Evaluation of Reinforced Concrete Buildings When Subjected to Tsunami Loads

Transcription

1 Evaluation of Reinforced Concrete Buildings When Subjected to Tsunami Loads by James Yokoyama and Ian N. Robertson Research Report UHM/CEE/14-01 Page i December, 2014

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3 ACKNOWLEDGMENTS This report is based on a Master of Science Research Report prepared by James Yokoyama under the direction of Ian Robertson. The authors would also like to thank Gary Chock for developing the prototype buildings used in this report and for providing valuable input and expertise. The authors also would like to thank Lyle Carden and Guangren Yu for providing the tsunami transect information for Hilo and Waikiki. The authors also thank Yuriy Mikhaylov for providing valuable information with his research on tsunami effects on reinforced concrete buildings. Finally, the authors wish to express their appreciation to Drs. Gaur Johnson and H. Ronald Riggs for reviewing this report. Page iii

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5 ABSTRACT The objective of this study was to develop prototypical designs of reinforced concrete buildings and evaluate them for resistance to tsunami loading following the provisions of ASCE 7: Chapter 6 Tsunami Loads and Effects. The mid-rise reinforced concrete building prototypical designs were developed according to the wind and seismic provisions of ASCE Two different types of reinforced concrete buildings were considered: a six story office building and a seven story residential building. Each of these prototype buildings was considered in three locations: Hilo Hawaii, Waikiki Hawaii and Monterey California. For each building and location, prototype designs were created for two different soil types: Soil Type B and Soil Type D. Once the prototype buildings were designed for wind and seismic loads, they were analyzed for tsunami loads appropriate for each building location. It was determined that redesign of some structural members was required for tsunami design of the buildings in Hilo and Waikiki. However, for the Monterey buildings, no redesign was required for the moment frame building and minimal redesign was needed for the shear wall building. Page v

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7 TABLE OF CONTENTS INTRODUCTION OVERVIEW TSUNAMI GENERATION INDIAN OCEAN TSUNAMI TOHOKU TSUNAMI... 5 LITERATURE REVIEW EVALUATION OF TSUNAMI LOADS AND THEIR EFFECT ON REINFORCED CONCRETE BUILDINGS FEMA P EVALUATION OF PROTOTYPICAL REINFORCED CONCRETE BUILDING PERFORMANCE WHEN SUBJECTED TO TSUNAMI LOADING... 8 TSUNAMI DESIGN PROVISIONS NOTATION LOAD CASES HYDROSTATIC LOADS Buoyancy HYDRODYNAMIC LOADS Overall Drag Force on Buildings and Other Structures Drag Force on Components Bore Loads on Vertical Structural Components DEBRIS IMPACT LOADS Alternative Simplified Debris Impact Static Load Design Instantaneous Debris Impact Force IMPORTANCE FACTORS LOAD COMBINATIONS ENERGY GRADE LINE METHOD DESIGN LOADS FOR PROTOTYPE BUILDINGS DESCRIPTION OF PROTOTYPE BUILDINGS DEAD LOADS Office Building Dead Loads Residential Building Dead Loads LIVE LOADS Office Building Live Loads Residential Building Live Loads WIND LOADS Notation Design Assumptions Wind Loads Hilo, Hawaii Wind Loads Waikiki, Hawaii Wind Loads Monterey, California SEISMIC LOADS Notation Seismic Load Distribution...37 PROTOTYPE BUILDING FINAL DESIGNS ETABS DRIFT ANALYSIS Special Moment Frame Office Building Design Intermediate Moment Frame Office Building Design OFFICE BUILDING Page vii

8 RESIDENTIAL BUILDING Hilo Residential Building Design Hilo Residential Building Design...47 TSUNAMI DESIGN LOADS OVERALL BUILDING DRAG FORCE COMPONENT DRAG FORCE Drag Force on Components Bore Loads on Vertical Structural Components DEBRIS IMPACT LOADS TSUNAMI BUILDING DESIGNS OFFICE BUILDING TSUNAMI DESIGNS Moment Frame Analysis Beam Designs Column Designs RESIDENTIAL BUILDING TSUNAMI DESIGNS Shear Wall Analysis Elevator Shear Wall Designs Stairwell Shear Wall Designs External Gravity Column Designs...70 MATERIAL QUANTITY COMPARISON MATERIAL QUANTITY COMPARISON CONCLUSIONS REFERENCES APPENDIX A HILO TSUNAMI DESIGN LOADS SAMPLE CALCULATION APPENDIX B ETABS MOMENT AND SHEAR DIAGRAMS APPENDIX C ENERGY GRADE LINE TRANSECT PROFILE PLOTS APPENDIX Page viii

9 LIST OF FIGURES Figure 1-1: Tsunami Generation... 4 Figure 4-1: Transect Lines for Hilo Building Location Figure 4-2: Transect Lines for Waikiki Building Location Figure 4-3: Transect Lines for Monterey Building Location Figure 4-4: Inundation Depths for Hilo Transect Lines Figure 4-5: Inundation Depths for Waikiki Transect Lines Figure 4-6: Flow Velocities Based on Distance from Shoreline for Hilo Transect Lines Figure 4-7: Flow Velocities Based on Distance from Shoreline for Waikiki Transect Lines Figure 5-1: Prototype Office Building Plan and Elevation Views Figure 5-2: Prototype Residential Building Plan and Elevation Views Figure 6-1: ETABS Model of Special Moment Frame Building with Hilo Soil D Seismic Loads Figure 6-2: ETABS Model of Special Shear Wall Building with Hilo Soil D Seismic Loads Figure 8-1: ETABS Model of Special Moment Frame Building with Hilo Tsunami Overall Building Drag Force Figure 8-2: ETABS North-South Special Moment Frame Column Moment Diagram Due to Hilo Tsunami Overall Building Drag Force Figure 8-3: RISA 2-D Special Moment Frame Column Moment Diagram Due to Hilo Tsunami Hydrodynamic Component Drag Force Figure 8-4: Location of Moment Frame Columns Affected by Overall Building Drag Force Figure 8-5: Hilo SMRF Beam Flexural Reinforcing Due to Tsunami Building Forces - Soil D Figure 8-6: Boundary reinforcing (left) and midspan reinforcing (right) for the Hilo Seismic Soil D first floor moment frame beams Figure 8-7: Boundary reinforcing (left) and midspan reinforcing (right) for the Hilo Tsunami Overall Building Drag Force first floor moment frame beams Figure 8-8: Boundary reinforcing the Hilo Seismic Soil D first floor moment frame columns Figure 8-9: Boundary reinforcing for the Hilo Tsunami Overall Building Drag Force first floor moment frame columns Figure 8-10: ETABS Model of Special Shear Wall Building with Hilo Tsunami Overall Building Drag Force Figure 8-11: ETABS Stairwell Shear Wall Moment Diagram Due to Hilo Tsunami Overall Building Drag Force Figure 8-12: RISA 2-D 12 Width Elevator Shear Wall Segment Moment Diagram Due to Hilo Tsunami Hydrodynamic Component Drag Force Figure 8-13: Reinforcing for the Hilo Seismic Soil D first floor elevator shear walls Figure 8-14: Reinforcing for the Hilo Tsunami Component Force first floor elevator shear walls Page ix

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11 LIST OF TABLES Table 3-1: Velocity and Flow Depths for Each Load Case Table 3-2: Tsunami Importance Factors Table 5-1: Wind Loads for Hilo Office Building Table 5-2: Wind Loads for Hilo Residential Building Table 5-3: Wind Loads for Waikiki Office Building Table 5-4: Wind Loads for Waikiki Residential Building Table 5-5: Wind Loads for Monterey Office Building Table 5-6: Wind Loads for Monterey Residential Building Table 5-7: Moment Frame Building Seismic Design Criteria Table 5-8: Shear Wall Building Seismic Design Criteria Table 5-9: Moment Frame Building Seismic Loads Soil D Table 5-10: Moment Frame Building Seismic Loads Soil B Table 5-11: Shear Wall Building Seismic Loads Soil D Table 5-12: Shear Wall Building Seismic Loads Soil B Table 6-1: Flexural Reinforcing of Typical Beam Sections Soil D Table 6-2: Shear Reinforcing of Typical Beam Sections Soil D Table 6-3: Flexural Reinforcing of Typical Beam Sections Soil B Table 6-4: Shear Reinforcing of Typical Beam Sections Soil B Table 6-5: Reinforcing of Typical Special MRF Column Sections Soil D Table 6-6: Reinforcing of Typical Intermediate MRF Column Sections Soil D Table 6-7: Reinforcing of Typical Special MRF Column Sections Soil B Table 6-8: Reinforcing of Typical Intermediate MRF Column Sections Soil B Table 6-9: Reinforcing of Typical Office Building Gravity Columns Table 6-10: Reinforcing of Typical Special Elevator Shear Walls Soil D Table 6-11: Reinforcing of Typical Ordinary Elevator Shear Walls Soil D Table 6-12: Reinforcing of Typical Special Stairwell Shear Walls Soil D Table 6-13: Reinforcing of Typical Ordinary Stairwell Shear Walls Soil D Table 6-14: Reinforcing of Typical Special Elevator Shear Walls Soil B Table 6-15: Reinforcing of Typical Ordinary Elevator Shear Walls Soil B Table 6-16: Reinforcing of Typical Special Stairwell Shear Walls Soil B Table 6-17: Reinforcing of Typical Ordinary Stairwell Shear Walls Soil B Table 6-18: Reinforcing of Typical Residential Building Gravity Columns Table 8-1: Hilo SMRF Beam Flexural Reinforcing Due to Overall Building Drag Force - Soil D Table 8-2: Hilo SMRF Beam Flexural Reinforcing Due to Overall Building Drag Force - Soil B Table 8-3: Hilo SMRF Beam Shear Reinforcing Due to Overall Building Drag Force - Soil D Table 8-4: Hilo SMRF Beam Shear Reinforcing Due to Overall Building Drag Force - Soil B Table 8-5: Hilo SMRF Column Reinforcing Due to Overall Building Drag Force - Soil D Table 8-6: Hilo SMRF Column Reinforcing Due to Overall Building Drag Force - Soil B Table 8-7: Waikiki IMRF Column Reinforcing Due to Overall Building Drag Force - Soil B Table 8-8: Hilo SMRF Column Reinforcing Due to Tsunami Component Forces - Soil D Table 8-9: Waikiki IMF Column Reinforcing Due to Tsunami Component Forces - Soil D Table 8-10: Hilo SMRF Column Reinforcing Due to Tsunami Component Forces - Soil B Table 8-11: Waikiki IMRF Column Reinforcing Due to Tsunami Component Forces - Soil B Table 8-12: Hilo Special Elevator Shear Wall Reinforcing Due to Tsunami Component Forces Table 8-13: Waikiki Elevator Shear Wall Reinforcing Due to Tsunami Component Forces Table 8-14: Monterey Elevator Shear Wall Reinforcing Due to Tsunami Component Forces Table 8-15: Hilo Special Stairwell Shear Wall Due to Overall Building Drag Force Soil D Table 8-16: Hilo Special Stairwell Shear Wall Due to Overall Building Drag Force Soil B Table 8-17: Hilo Residential Building Exterior Gravity Column Reinforcing Due to Tsunami Component Forces Page xi

12 Table 8-18: Oahu Residential Building Exterior Gravity Column Reinforcing Due to Tsunami Component Forces Table 9-1: Concrete Quantity Comparison Table 9-2: Reinforcement Quantity Comparison Page xii

13 1 Introduction 1.1 Overview All structures in the United States of America are designed for both gravity loads and lateral loads. The two main categories of lateral loads that are considered during the structural design phase are wind and seismic loads. Special detailing can be incorporated into the design of structures to allow the structure to withstand earthquakes and hurricanes to prevent collapse. However, there are currently limited design provisions provided by building codes to design structures for tsunami loads. Tsunamis have the potential to cause widespread destruction and massive loss of life in coastal areas, as evidenced by recent natural disasters such as the 2004 Indian Ocean tsunami and the 2011 Tohoku tsunami. With the implementation of a tsunami building code to guide design of structures to withstand tsunamis, such destruction can possibly be prevented. Hawaii is particularly at risk for a major tsunami due to its geographical location. Therefore, Hawaii s vulnerability emphasizes the importance of its structures being designed to withstand major tsunamis. A proposed Chapter 6 of the ASCE 7 Standard (ASCE, 2010) has been developed to establish a design standard for use in coastal areas in the United States susceptible to tsunamis, including Hawaii. The objective of this report is to create mid-rise reinforced concrete buildings designed according to the wind and seismic provisions of ASCE 7-10, and evaluate them for resistance to tsunami loading following the provisions of ASCE 7: New Chapter 6 Tsunami Loads and Effects. Page 1

14 1.2 Tsunami Generation Tsunamis are generated when a significant volume of water in the ocean is displaced in a short amount of time. In most cases, this displacement is caused by earthquakes on the ocean floor. A subduction zone is an area on the earth s crust where two tectonic plates move toward one another, with one plate riding over the other. The overriding plate forces the subduction plate down into the mantle of the earth with plate tectonic forces. Due to roughness of the plate surfaces, friction causes the overriding plate to become stuck on the subduction plate. Continued motion between the plates increases stress in the overriding plate over time, thereby deforming the overriding plate. Eventually, the energy accumulated in the overriding plate exceeds the friction forces, causing the plate to snap back into its original position, thereby causing an earthquake. Such earthquakes at subduction zones (as opposed to earthquakes at convergent or transform boundaries) are particularly dangerous, because these earthquakes cause the vertical deformation necessary for a tsunami to form in the ocean. If a subduction zone earthquake occurs on the ocean floor, the overriding plate pushes water up as it snaps back to its original position (Fig. 1-1). The deformation of water can cause a tsunami. When the tsunami is far from shore in deep water, it has a long wave length and small amplitude. The amplitude of a tsunami in deep water is generally small. Due to this low amplitude, tsunamis are difficult to detect when far from shore. As a tsunami approaches shallower water, it increases in height due to wave shoaling. As a tsunami gets closer to shore increased friction from the ocean floor due to shallower waters cause wave speed and wave length to decrease. However, the energy of the wave Page 2

15 must remain constant, so this reduction in speed and wave length is compensated with a significant increase in wave height. In major tsunamis, waves tend to break offshore before approaching land as bores (powerful walls of turbulent water). These bores run deep inland and can cause major damage to whatever exists in their path. After the bore reaches its maximum run up, the water then recedes back into the ocean, causing even more damage. In most cases, tsunamis come in sets of waves. After each consecutive wave, the water that runs inland recedes preparing for inundation of the next wave. As this cycle repeats itself, more and more damage is caused to the tsunami inundation zone. Debris from damages structures that recedes into the ocean can be launched back inland with the next wave, behaving as a projectile and further magnifying the damage caused by each successive wave. Page 3

16 1.3 Indian Ocean Tsunami Figure 1-1: Tsunami Generation On December 26 th 2004, a 9.3 magnitude earthquake occurred along a subduction zone at the Northeast edge of the Indian Ocean. The earthquake resulted in a major tsunami which hit many countries in the Indian Ocean, including Indonesia, Sri Lanka, India, Thailand, and Malaysia. The tsunami resulted in widespread damage of structures in the affected countries. The Canadian Association for Earthquake Engineering (CAEE) wrote a reconnaissance report following the Indian Ocean Tsunami (CAEE, 2005). A team of Page 4

17 engineers visited Thailand and Indonesia to examine the performance of coastal structures. It was determined that lateral forces generated by the tsunami waves were much larger than design wind forces. The lateral forces from the tsunami waves were large enough to damage unreinforced masonry walls within the height of the wave. In addition to unreinforced masonry buildings, it was also determined that low rise non-engineered reinforced concrete frame buildings and low-rise timber frame structures suffered major damage due to tsunami wave forces. These buildings were also damaged extensively by impact forces from floating debris. However, the report also determined that engineered reinforced concrete frames appeared to have sufficient strength to withstand tsunami forces. The engineers observed that structural components of engineered reinforced concrete buildings sustained little damage. It was observed that nonstructural elements of these buildings would often fail before critical loads were achieved on structural members. The failure of the nonstructural members thereby relieved some pressure on the structural elements of the building. 1.4 Tohoku Tsunami On March 11 th 2011, a 9.0 magnitude subduction earthquake hit approximately 100 kilometers off the northeast (Tohoku) coast of Honshu, the main island of Japan. The earthquake generated a major tsunami which affected much of the Tohoku region of Japan. According to the Japan Meteorological Agency, the movement of ocean floor was estimated to be 3 meters upward and 24 meters laterally at the megathrust fault (Chock et al. 2011). The Japanese government estimates that 264,468 buildings either collapsed or partially collapsed primarily from tsunami inundation. It was also estimated that the disaster caused over $217 billion in damages. There were over 20,000 fatalities or missing persons in the tsunami-affected coastal areas of Honshu (Chock et al. 2011). Page 5

18 From April 15 to May , a team from the ASCE 7 Subcommittee on Tsunami Loads & Effects performed a reconnaissance visit to survey the effects of the Tohoku tsunami. The team focused on tsunami effects on coastal buildings, bridges, port facilities, and coastal protective structures. It was observed that nearly all residential light frame buildings completely collapsed in areas with a tsunami inundation of a story height or more. In coastal inundation areas, 75%-95% of low rise buildings collapsed. However, several taller multistory buildings survived the disaster and retained structural integrity in their vertical load carrying members and foundation. A significant number of the surviving buildings did not seem to have significant structural damage from either the earthquake or tsunami forces. Mid-rise buildings with robust columns or shear walls also performed relatively well if the building was high enough. This lack of structural damage in a number of the buildings shows potential tsunami resistance of larger modern buildings with robust seismic designs and uplift-resistant foundations. The results of this study proved that it is very realistic for taller structures to be designed to withstand tsunami events, thereby allowing the buildings to serve as vertical evacuation refuges. Page 6

19 2 Literature Review 2.1 Evaluation of Tsunami Loads and Their Effect on Reinforced Concrete Buildings In Evaluation of Tsunami Loads and Their Effect on Reinforced Concrete Buildings (Pacheco and Robertson, 2005), the performance of typical reinforced concrete buildings was analyzed under tsunami loads. The analysis was used to determine the buildings potential for vertical evacuation. Tsunami forces were calculated based on guidelines from the City and County of Honolulu Building Code (CCH, 2000) and the Federal Emergency Management Agency Coastal Construction Manual, (FEMA 2000). The buildings that were analyzed were prototype buildings designed by S.K. Ghosh and David Fanella in Seismic and Wind Design of Concrete Buildings (Ghosh and Fanella, 2003). It was determined from this study that the moment resisting frame building and shear wall frame building design for high seismic design categories were able to resist the tsunami forces. However, individual shear walls subjected to out of plane tsunami forces could possibly fail, leading to progressive collapse. The prototype bearing wall structure performed poorly under tsunami loads. However, this research had some shortcomings. The prototype reinforced concrete buildings were oversimplified and not representative of typical coastal buildings which would be at risk for tsunamis. Also, the tsunami load calculation guidelines in CCH and FEMA 2000 were oversimplified and did not adequately model tsunami flow force. It was concluded in the study that experimental validation of tsunami velocity and flow depth was needed and that wave tank studies needed to be performed to verify debris and hydrodynamic tsunami loading. Page 7

20 2.2 FEMA P-646 In 2004, the Federal Emergency Management Agency (FEMA) began a project to develop design guidelines for structures to withstand both tsunami and earthquake loads. FEMA addressed this issue due to the multitude of areas on the west coast of the United States that are vulnerable to a major tsunami. These communities are extremely vulnerable to a tsunami caused by an earthquake on the Cascadia subduction zone. Such a tsunami could potentially reach to the coastline within 20 minutes after the earthquake, making horizontal evacuation extremely difficult in at-risk communities on the west coast. In such cases, the best chance for survival would be to evacuate vertically up a building designed to withstand tsunami loads. This concept was shown to be effective in the Indian Ocean tsunami, where many people were able to survive by evacuating to upper floors of engineered reinforced concrete buildings. In 2008, Guidelines for Design of Structures for Vertical Evacuation from Tsunamis (FEMA P-646) was published, which provides guidance on tsunami structural design for coastal regions (FEMA 2008). FEMA P-646 includes information on tsunami assessment, load determination, structural design criteria, and options for vertical evacuation. In 2012, the second edition of FEMA P-646 was published (FEMA 2012). The second edition updated reference documents to current versions, provided observations and lessons learned based on the 2011 Tohoku tsunami, and revised debris impact load equations. 2.3 Evaluation of Prototypical Reinforced Concrete Building Performance When Subjected to Tsunami Loading In Evaluation of Prototypical Reinforced Concrete Building Performance When Subjected to Tsunami Loading (Mikhaylov and Robertson, 2009), multi-story reinforced concrete residential and office buildings were designed for three different seismic Page 8

21 conditions using IBC The seismic conditions were chosen such that they represented conditions common to different locations in Hawaii. Each of these buildings was then analyzed under tsunami loads calculated using the first edition of FEMA P-646 (FEMA 2008) to determine if it could be used for tsunami evacuation. If the building was deemed inadequate according to tsunami design standards, the amount of additional concrete and reinforcement needed to make the structure tsunami resistant was determined. The study concluded that multi-story reinforced concrete office and residential buildings can be realistically designed to survive major tsunamis and can be used for vertical evacuation. It was determined that the prototype buildings in the study would need less than an 8% increase in reinforcing steel weight and less than a 3% increase in concrete volume in order to become tsunami resistant. It was also determined that special moment-resisting frame structures designed for high seismic conditions may not need upgrades to resist tsunami loads. However, structural walls subject to out-of-plane shear from tsunami loads may need additional shear reinforcement. Also, it was concluded that debris impact loads from shipping containers would likely lead to shear and/or bending failure of individual reinforced concrete columns. Therefore, tsunami- resistant buildings should be designed to prevent progressive collapse in case of an individual column failure. From the study, shortcomings of the first edition of FEMA P-646 were discovered. It was concluded that the maximum water depth and bore velocity as calculated by FEMA P- 646 were very low and did not accurately represent a typical tsunami bore. In Characterization of Tsunami-Like Bores in Support of Loading on Structures (Mohamed, 2008), small tsunami waves were tested on wet and dry beds and equations were created to determine the velocity of a tsunami bore. It was concluded that Mohamed s equation for Page 9

22 tsunami wave velocity on a wet bed better represented the actual velocity of an expected tsunami bore in Waikiki than FEMA P-646 s wave velocity equation. Therefore, Mohamed s flow velocity equation was used for the determination of tsunami forces on the building. According to Mikhaylov and Robertson, another shortcoming of the first edition of FEMA P-646 was an inaccurate estimation of the stiffness of shipping containers. FEMA P-646 suggested that the mass of an empty shipping container should be used in the design process. However, in the event of a major tsunami, there exists a possibility that a filled shipping container could act as a floating projectile force. A filled shipping container would have greater mass, possibly resulting in larger debris loads. The report also concluded that the shipping container stiffness values provided by FEMA P-646 were considered too high. For the tsunami design in the report, more accurate container stiffness was estimated by examining and measuring several different shipping containers. Page 10

23 3 Tsunami Design Provisions For this report, ASCE 7: Chapter 6 Tsunami Loads and Effects will be used to calculate the tsunami loads used in the analysis of the prototype buildings. This document consists of a set of proposals to establish the first national design standard for tsunami design. This chapter of the ASCE 7 code would be used for tsunami design in Alaska, Washington, Oregon, California and Hawaii, where there exists a quantifiable tsunami risk. According to the draft chapter, structural engineers in these states are being asked to incorporate tsunami-resilient designs in critical structures, thereby creating a need for an engineering standard for tsunami design. The proposed ASCE 7 Chapter 6 categorizes tsunami loads into hydrostatic loads, hydrodynamic loads, and debris impact loads. 3.1 Notation A beam Vertical projected area of a beam element A col Vertical projected area of a column element A wall Vertical projected area of a wall b Width subject to force B Building width C cx Ratio of solid element area to the overall building area or closure coefficient C d Drag coefficient, from Table in Chapter 6 F d Drag force on a component F dx Drag force on a structure at each level F i Debris impact design force Page 11

24 F ni Nominal maximum instantaneous debris impact force F v Buoyancy force F w Tsunami load on vertical structural components h Tsunami inundation depth h e Inundated height of an element h max Maximum inundation depth h s Top of floor slab elevation h sx Story height of a given story x I tsu Importance factor of tsunami forces k Effective stiffness of the impacting debris m d Mass of debris object u Tsunami flow velocity u max Maximum tsunami flow velocity V w Displaced water volume γ s Fluid weight density ρ s Fluid mass density 3.2 Load Cases For calculation of tsunami loads, three load cases need to be analyzed. Each load case represents different critical design stages of structural loading. Page 12

25 Load Case 1 is the loading situation associated with maximum buoyancy. The structure is designed with a maximum buoyant force and the associated hydrodynamic forces. The main purpose of checking this load case is to check the stability of the structure and its foundation against net uplift. Load Case 2 is associated with maximum flow velocity of the tsunami, thereby resulting in maximum hydrodynamic forces on the structure. Load Case 2 uses two-thirds of the max inundation depth. Load Case 3 is associated with maximum inundation depth. For Load Case 3, velocity is assumed to be one-third the maximum velocity. The maximum flow depth and velocity at each site were determined using the Energy Grade Line Method proposed in ASCE 7 Chapter 6. Table 3-1 lists the velocity and flow depth for each load case at each building location. Table 3-1: Velocity and Flow Depths for Each Load Case Flow Parameters Hilo Waikiki Monterey Max. Inundation Depth, h max (ft) Max. Flow Velocity, u max (fps) Hydrostatic Loads Hydrostatic tsunami loads occur in structures due to standing or slowly moving water. Hydrostatic loads imparted on structures can be split into three main categories: buoyancy, unbalanced lateral hydrostatic forces, and residual water surcharge loads. For the purposes of this project, only the buoyant forces were calculated for the design of the structures. However, we are assuming the slab-on-grade of both the office and residential buildings to be non-structural. A non-structural slab implies that the grade beams are not tied into the slab-on-grade. Therefore it was assumed that buoyancy forces would not result in building uplift. Page 13

26 3.3.1 Buoyancy Uplift due to buoyancy is an upward force that results from air being trapped in an enclosed inundated portion of a structure. Buoyancy needs to be considered in enclosed spaces without breakaway walls that have an opening area of less than 25% of the exterior wall area. Buoyant force equals the weight of the water being displaced, and can be calculated using Equation Hydrodynamic Loads F v = γ s V w Equation 3-1: Buoyant Force Hydrodynamic tsunami loads are caused by water flowing around structural components at a moderate to high velocity. These forces can be caused by either incoming or outgoing flow. According to the proposed ASCE 7 Chapter 6, a structure s lateral force resisting system and all structural components below the tsunami inundation elevation must be designed for hydrodynamic forces Overall Drag Force on Buildings and Other Structures The lateral force resisting system of the building must be designed to resist hydrodynamic tsunami drag forces at each level. This force can be caused by either incoming or outgoing flow. The overall drag force on a building can be calculated with Equation 3-2. F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) Equation 3-2: Tsunami Overall Building Drag Force C cx is defined as the closure ratio and can be calculated with Equation 3-3. Page 14

27 C cx = (A col + A wall ) + 1.5A beam Bh sx Equation 3-3: Closure Ratio C d, the drag coefficient for the building, is determined from ASCE 7 Chapter 6 Table , and is based on the width to inundation depth ratio Drag Force on Components For designing components of the building, a design hydrodynamic drag force on components was also used. The drag force, calculated with Equation 3-4, was applied as a pressure on the projected inundated height of all structural components below the inundation depth. F d = 1 2 ρ si tsu C d b(h e u 2 ) Equation 3-4: Component Drag Force For exterior components, debris accumulation was included with a C d value of 2.0. For interior components, ASCE 7 Chapter 6 Table gives a C d value of 2 for square/rectangular columns Bore Loads on Vertical Structural Components Where the flow at a site has a Froude number greater than 1.0, and the vertical component width to inundation ratio is three or more, the foce on the wall is 50% larger than the drag force and is given by Equation 3-5. F w = 3 4 ρ si tsu C d b(h e u 2 ) bore Equation 3-5: Hydrodynamic Bore Load Out of the three locations studied, the Waikiki and Hilo locations were determined to have the potential for tsunami bores. Hilo was determined to have potential for tsunami bores Page 15

28 due to recorded historical evidence of bores during a past tsunami. Waikiki was determined to have potential for tsunami bores due to its fringing reef. 3.5 Debris Impact Loads Structural components on the structure were also designed for debris impact loads. Debris impact loads are caused by large debris (such as shipping containers and logs) striking the component during a tsunami. Debris impact forces must be considered when the minimum inundation depth is three feet or greater. Both static and dynamic analyses can be performed to determine the debris impact on a component Alternative Simplified Debris Impact Static Load The alternative simplified debris impact static load method from ASCE 7 Chapter 6 was used as the maximum static debris load on the components of the structure. The simplified debris impact static load can be determined from Equation 3-6. F i = 330C o I tsu Equation 3-6: Simplified Debris Impact Static Load C o is the orientation coefficient and is equal to 0.65 in all cases. When the building site is not in an impact zone for shipping containers, ships, and barges, the simplified debris impact load from equation 3-6 can be reduced by 50%. It was assumed that the Hilo location was in an impact zone for shipping containers. However, the Oahu and Monterey locations were not in an impact zone for shipping containers. The alternative simplified debris impact load controlled the debris loading for the Hilo and Waikiki locations Design Instantaneous Debris Impact Force The design instantaneous debris impact force from ASCE 7 Chapter 6 was used to determine the static debris load on components of the structure. The nominal instantaneous debris impact force was determined from Equation 3-7. Page 16

29 F ni = u max (km d ) 0.5 Equation 3-7: Nominal Instantaneous Debris Impact Force The design instantaneous debris impact force was determined from Equation 3-8. F i = I tsu C o F ni Equation 3-8: Design Instantaneous Debris Impact Force C o is the orientation coefficient and is equal to 0.65 in all cases. In Hilo and Waikiki, equation 3-8 calculated debris impact forces which were greater than the value determined with the simplified debris impact load equation, which acts as the maximum static debris load for design. Therefore, the design instantaneous debris impact force was only used as the controlling debris impact force for the Monterey location. 3.6 Importance Factors The importance factors from ASCE 7 Chapter 6 Section , given in Table 3-1, were considered when determining tsunami loads. For both the office and residential buildings, Tsunami Risk Category II was assumed. Table 3-2: Tsunami Importance Factors Tsunami Risk Category I TSU II 1.0 III 1.25 Tsunami Risk Category IV, Vertical Evacuation Refuges, and Tsunami Risk 1.25 Category III Critical Facilities 3.7 Load Combinations The following load combinations from ASCE 7 Chapter 6 Section , given by Equations 3-9 and 3-10, were considered when designing for tsunami loads. Page 17

30 0.9D + FTSU + HTSU Equation 3-9: Tsunami Load Combination 1 1.2D + FTSU + 0.5L + 0.2S + HTSU Equation 3-10: Tsunami Load Combination 2 Page 18

31 4 Energy Grade Line Method In order to determine the tsunami forces on the structures, the maximum tsunami inundation depth and maximum tsunami flow velocity are required. The Energy Grade Line Method is a stepwise procedure that can be used to determine the maximum inundation depth and maximum flow velocity at any site between the shoreline and the inundation limit. Starting from the runup elevation at the inundation limit, the flow parameters are determined progressing shoreward to get the tsunami velocity and inundation depth at the site of the building. The following are the steps that were taken for the Energy Grade Line Method: Runup and Inundation Limit values were obtained. For the Monterey building, a site specific analysis was used to determine the Runup and Inundation Limit values. For the Hilo and Waikiki locations, the Runup and Inundation Limit values were obtained from maps created by Prof. Fai Cheung based on the Great Aleutian Tsunami (Cheung). The transect lines were approximated by a series of x-z grid coordinates of the points, which create a series of segmented slopes. X is the horizontal distance measured from the shoreline, and z is the topographic elevation. For each of the locations of the buildings, transect lines were created for tsunami flow acting perpendicular to the shoreline, flow acting 22.5 degrees clockwise from the perpendicular line, and flow acting 22.5 degrees counterclockwise from the perpendicular line. This allows for variation of the direction of the tsunami within a 45 degree envelope. See Figures 4-1, 4-2, and 4-3 for the transect lines for Hilo, Oahu, and Monterey, respectively. Page 19

32 Figure 4-1: Transect Lines for Hilo Building Location Page 20

33 Figure 4-2: Transect Lines for Waikiki Building Location Page 21

34 Figure 4-3: Transect Lines for Monterey Building Location The topographic slope, i, of each segment, or pair of consecutive points, was determined along the transect line. The topographic slope is calculated as the ratio of elevation difference and distance between two adjacent points on the transect. i = z i z i+1 x i x i+1 The Manning s Coefficient, n, was determined based on the terrain along the transect line. The Manning s Coefficient can be obtained from the draft Chapter 6 Table An n value of 0.03 was assumed for all three locations. The Froude number, F ri, was calculated for each point along the transect. The Froude number can be calculated with the draft Chapter 6 Equation Page 22

35 F ri = (1 x 0.5 ) x R The hydraulic friction slope, s i was calculated the draft Chapter 6 Equation The calculation for the slope began at the runup point and progressed toward the shoreline. At the runup point, a nominally small value of h i (0.1 feet) was used to avoid a singularity. s i = 2 gf ri (( 1.49 n ) 2 h i 1 3 ) The hydraulic energy head, E i+1, was calculated at successive points progressing toward the shoreline. E g,i+1 = E g,i + ( i + s i ) x i The inundation depth, h i+1, was determined at each point along the transect line. E g,i+1 h i+1 = ( F ri 2 ) The velocity of flow at each point was calculated. The equation for velocity is derived from the equation for the Froude number. u i+1 = F ri (gh) 0.5 Section states that flow velocity used in the tsunami load equations may not be less than 10 ft/s but it need not be greater than 50 ft/s. The flow velocity and flow depth were calculated for each point along the three transect lines for each location. See Figures 4-4 through 4-7 for the flow depths and flow velocities for Hilo and Waikiki along the transect lines. The critical h and u values out of the three transect lines at the project site Page 23

36 were chosen as the design h max and u max values. From the Energy Grade Line Method analysis, it was determined that the maximum inundation depths to be used for design at the building locations in Hilo and Waikiki would be 55 feet and 25 feet, respectively. The EGL method also determined that the maximum flow velocity to be used for design in Hilo and Waikiki would be 35.8 ft/s and 28 ft/s, respectively. Figure 4-4: Inundation Depths for Hilo Transect Lines Page 24

37 Figure 4-5: Inundation Depths for Waikiki Transect Lines Figure 4-6: Flow Velocities Based on Distance from Shoreline for Hilo Transect Lines Page 25

38 Figure 4-7: Flow Velocities Based on Distance from Shoreline for Waikiki Transect Lines Page 26

39 5 Design Loads for Prototype Buildings 5.1 Description of Prototype Buildings For this project, two different types of reinforced concrete buildings with different structural systems are to be analyzed. The two buildings are a six story office building and a seven story residential building. Each of these prototype buildings are to be analyzed in three locations: Hilo, Hawaii, Waikiki, Hawaii and Monterey, California. The six story office building consists of moment resisting frames, a flat plate floor system, and interior gravity load resisting columns. The Hilo and Monterey buildings have perimeter and interior special moment frames, while the Waikiki building has perimeter intermediate moment frames. The seven story residential building consists of shear walls at elevators and stairwells, a flat plate floor system, and gravity load resisting columns. The Hilo and Monterey buildings have special reinforced concrete shear walls, while the Waikiki building has ordinary reinforced concrete shear walls. Page 27

40 Figure 5-1: Prototype Office Building Plan and Elevation Views Page 28

41 5.2 Dead Loads Figure 5-2: Prototype Residential Building Plan and Elevation Views Office Building Dead Loads The following dimensions were used for the self-weight of the office building: Building Plan Dimensions: 88 x 254 Assumed Interior Column Dimensions: 24 x 24 Assumed Exterior Column Dimensions: 30 x 30 Assumed Beam Dimensions: 24 x30 Slab Thickness: 8 The following gravity loads were assumed: 8 Slab: 100 psf Page 29

42 Floor Finish/Tapered Roofing: 5 psf Ceiling/Insulation: 5 psf Mechanical, Electrical and Plumbing (MEP): 10 psf Perimeter Window Wall: 10 psf x 12 ft = 120 plf (at each level except the roof) Using these values, an assumed concrete unit weight of 150 pcf, and an assumed 25% sustained live load, a typical floor weight of 4202 kips and a roof weight of 4107 kips was calculated. These values result in a total building seismic weight of approximately kips for the office building Residential Building Dead Loads The following dimensions were used for the self-weight of the residential building: Building Plan Dimensions: 64 x 254 Assumed Column Dimensions: 20 x 20 Assumed Shear Wall Thickness: 10 Slab Thickness: 8 The following gravity loads were assumed: 8 Slab: 100 psf Floor Finish/Tapered Roofing: 10 psf (typical floor), or 5 psf (roof) Ceiling/Insulation: 8 psf Mechanical, Electrical and Plumbing (MEP): 10 psf Perimeter Window Wall: 10 psf x 12 ft = 120 plf (at each level except the roof) Using these values, an assumed concrete unit weight of 150 pcf, and an assumed 25% sustained live load, a typical floor weight of 2771 kips and a roof weight of 2999 kips was calculated. These values result in a total weight of approximately kips for the residential building. Page 30

43 5.3 Live Loads Office Building Live Loads The following live loads were assumed for the office building based on Table 4-1 of ASCE 7-10: Corridors: 80 psf Offices: 50 psf Stairs: 100 psf Partitions: 15 psf Roof: 20 psf It was assumed that the corridor is 10 feet wide down the long direction center line of each floor Residential Building Live Loads The following live loads were assumed for the residential building based on Table 4-1 of ASCE 7-10: Typical Floor Area: 40 psf Stairs: 100 psf Partitions: 15 psf Roof: 20 psf Live load reductions were taken using ASCE 7-10 Section 4.8, which allows up to a 60% reduction in live load for members supporting two or more floors. Live load reductions were taken into account for the design of the columns and shear walls. 5.4 Wind Loads Notation V Effective wind speed, from ASCE 7-10 Figure (mph) I Importance factor, from ASCE 7-10 Page 31

44 Z Height above ground level (ft) K d Wind directionality factor, from the Hawaii State Building Code Amendments K z Velocity pressure exposure coefficient evaluated at height Z, from ASCE 7-10 Table K h Velocity pressure exposure coefficient evaluated at height Z=h, from ASCE 7-10 Table K zt Topographic Factor from the Hawaii State Building Code Amendments G Gust effect factor, from ASCE 7-10 Section 26.9 C p External pressure coefficient, from ASCE 7-10 Figure C pi Internal pressure coefficient, from ASCE 7-10 Figure q z Velocity pressure evaluated at height Z (psf) q h Velocity pressure evaluated at height Z=h (psf) P Design wind pressure (psf) P W Design wind pressure acting on windward face (psf) P L Design wind pressure acting on leeward face (psf) Design Assumptions The Directional Procedure from ASCE 7-10 Chapter 27 was used for determination of wind loads. Based on Figure , V=130 miles per hour for Hawaii. The importance factor = 1.0 for residential and office buildings. Page 32

45 Both the reinforced concrete office building and residential buildings are assumed to be rigid structures, resulting in G=0.85 from ASCE 7-10 Section According to ASCE 7-10 Figure , the external pressure coefficient Cp for the windward wall is 0.8, while the external pressure coefficient Cp for the leeward wall is -0.5 for north-south winds, and for east-west winds Wind Loads Hilo, Hawaii A) Office Building Table 5-1 gives the wind loads determined for the Office Building located in Hilo. Table 5-1: Wind Loads for Hilo Office Building Floor Z (ft) NS Direction EW Direction Pw (psf) PL (psf) P (psf) Fstory (k) Pw (psf) PL (psf) P (psf) Fstory (k) Base B) Residential Building Table 5-2 gives the wind loads determined for the Residential Building located in Hilo. Page 33

46 Table 5-2: Wind Loads for Hilo Residential Building Floor Z (ft) NS Direction EW Direction Pw (psf) PL (psf) P (psf) Fstory (k) Pw (psf) PL (psf) P (psf) Fstory (k) Base Wind Loads Waikiki, Hawaii A) Office Building Table 5-3 gives the wind loads determined for the Office Building located in Waikiki. Table 5-3: Wind Loads for Waikiki Office Building Floor Z (ft) NS Direction EW Direction Pw (psf) PL (psf) P (psf) Fstory (k) Pw (psf) PL (psf) P (psf) Fstory (k) Base B) Residential Building Table 5-4 gives the wind loads determined for the Residential Building located in Waikiki. Page 34

47 Table 5-4: Wind Loads for Waikiki Residential Building Floor Z (ft) NS Direction EW Direction Pw (psf) PL (psf) P (psf) Fstory (k) Pw (psf) PL (psf) P (psf) Fstory (k) Base Wind Loads Monterey, California A) Office Building Table 5-5 gives the wind loads determined for the Office Building located in Monterey. Table 5-5: Wind Loads for Monterey Office Building Floor Z (ft) NS Direction EW Direction Pw (psf) PL (psf) P (psf) Fstory (k) Pw (psf) PL (psf) P (psf) Fstory (k) Base B) Residential Building Table 5-6 gives the wind loads determined for the Residential Building located in Monterey. Page 35

48 Table 5-6: Wind Loads for Monterey Residential Building Floor Z NS Direction EW Direction Pw (psf) PL (psf) P (psf) Fstory (k) Pw (psf) PL (psf) P (psf) Fstory (k) Base Seismic Loads To determine the design seismic loads, the Equivalent Lateral Force Procedure from ASCE 7-10 Section 12.8 was used. All seismic design coefficients for the respective sites were obtained from the USGS online seismic design tool. Occupancy Category II was assumed for all sites. Seismic design provisions for Soil Type B and D were obtained to compare seismic designs for both poor soil and good soil conditions Notation S S 0.2 second response acceleration S second response acceleration S DS Design spectral acceleration parameter based on SS S D1 Design spectral acceleration parameter based on S1 F a Site coefficient based on SS F V Site coefficient based on S1 I Importance factor, from ASCE 7-10 Table C S Seismic response coefficient, from ASCE 7-10 Section Page 36

49 T a Approximate fundamental period, from ASCE 7-10 Section R Response modification factor, from ASCE 7-10 Table SDC Seismic Design Category, from ASCE 7-10 Section 11.6 W Seismic dead weight (kips) V Seismic base shear (kips) Table 5-7: Moment Frame Building Seismic Design Criteria Office Moment Frame Building Seismic Design Criteria Location Soil Type SDC S s S DS S 1 S D1 Ta (s) R Cs Hilo - Special MF B D Hilo - Special MF D D Monterey - Special MF B D Monterey - Special MF D D Oahu - Intermediate MF B C Oahu - Intermediate MF D C Table 5-8: Shear Wall Building Seismic Design Criteria Residential Shear Wall Building Seismic Design Criteria Location Soil Type SDC S s S DS S 1 S D1 Ta (s) R Cs Hilo - Special SW B D Hilo - Special SW D D Monterey - Special SW B D Monterey - Special SW D D Oahu - Ordinary SW B C Oahu - Ordinary SW D C Seismic Load Distribution Using the Equivalent Lateral Force Procedure, the base shears of the respective buildings were obtained and distributed throughout the floors of the buildings. After completing both the seismic and wind load analysis, it was determined that the seismic loading would control the lateral force demand for all buildings and locations. Page 37

50 Table 5-9: Moment Frame Building Seismic Loads Soil D Level W x (k) h x (ft) h x k (ft) w x h x k (ft-k) C vx FxHILO (k) FxWAIKIKI (k) FxMONTEREY (k) Roof SUM Table 5-10: Moment Frame Building Seismic Loads Soil B Level W x (k) h x (ft) h x k (ft) w x h x k (ft-k) C vx FxHILO (k) FxWAIKIKI (k) FxMONTEREY (k) Roof SUM Table 5-11: Shear Wall Building Seismic Loads Soil D Level W x (k) h x (ft) h x k (ft) w x h x k (ft-k) C vx FxHILO (k) FxWAIKIKI (k) FxMONTEREY (k) Roof SUM Page 38

51 Table 5-12: Shear Wall Building Seismic Loads Soil B Level W x (k) h x (ft) h x k (ft) w x h x k (ft-k) C vx FxHILO (k) FxWAIKIKI (k) FxMONTEREY (k) Roof SUM Page 39

52 Page 40

53 6 Prototype Building Final Designs 6.1 ETABS Drift Analysis ETABS was used to determine the final design dimensions the lateral force resisting members of both the moment frame and shear wall buildings (Fig 6-1 and 6-2). The lateral loads were applied to the buildings to determine the drift of the structure. The member sizes were then optimized by comparing the inelastic story drift values to the seismic allowable story drift calculated using ASCE 7-10 Table A lateral drift limit of H/400 was also checked for the lateral displacement at the roof of the structure when subjected to wind loads. For this case, elastic cracked section properties based on ACI Section were used. In order to model elastic cracked section properties, a modification factor of 0.7 was applied to the flexural stiffness of the columns and walls and a modification factor of 0.35 was applied to the flexural stiffness of the beams. From this analysis, the special moment frame building required 28 square columns with 30 wide by 24 deep beams. Moment frames are provided on the perimeter of the special moment frame building with two additional moment frames spanning in the short direction in the interior of the building. The intermediate moment frame building required 20 square columns with 20 wide by 26 deep beams. The special shear wall buildings were determined to have 10 thick shear walls. Although the drift analyses determined that thinner walls could be permitted for the ordinary shear wall buildings, walls thinner than 10 were deemed not to be practical. Page 41

54 Figure 6-1: ETABS Model of Special Moment Frame Building with Hilo Soil D Seismic Loads Page 42

55 Figure 6-2: ETABS Model of Special Shear Wall Building with Hilo Soil D Seismic Loads Special Moment Frame Office Building Design For the design of the special reinforced concrete moment frame, provisions of ACI Chapter 21 were used. Controlling shear and moment values obtained from the ETABS analysis for seismic loading were combined with gravity shear and moment values using the appropriate load combinations. For the purposes of this project, two typical special moment frame beam designs were performed: a typical 28 beam design and a typical 10 beam design. The 28 beam design was chosen because of its likelihood to control flexural reinforcing design. Likewise, the 10 beam was chosen because it was assumed that the shortest beam would control shear design for the special moment frame. These assumptions proved to be correct for the special moment frame design. One typical column was designed for the special reinforced Page 43

56 moment frame. PCA Column was used to assist in the design of the column longitudinal reinforcing. Tables 6-1 through 6-4 show the flexural and shear reinforcing for the beams and Tables 6-5 and 6-7 show the reinforcing of the column Intermediate Moment Frame Office Building Design For the ordinary reinforced concrete moment frame, simple beam and column design was performed. Controlling values for both shear and moment were obtained from the Oahu ETABS model to create a typical beam and column design. PCA Column was used to assist in the design of the longitudinal reinforcing of the column. See Tables 6-1 through 6-4 for the flexural and shear reinforcing for the beams and Tables 6-6 and 6-8 for the reinforcing of the column. 6.2 Office Building Tables 6-1 through 6-4 display the flexural and shear reinforcing designs of typical beam sections for the office building. Tables 6-5 through 6-9 display the reinforcing designs of typical columns for the office building. The seismic force values of both the Hilo and Monterey building were very similar, with the Hilo moment frame building having slightly larger seismic forces. Therefore, it was determined that all special moment frame calculations would use the values obtained from the Hilo seismic load calculations. Due to the similarity of forces between the two cases, two different special moment frame designs were not necessary. The intermediate moment frame building was designed using the Waikiki seismic loads. Page 44

57 Table 6-1: Flexural Reinforcing of Typical Beam Sections Soil D MRF BEAM FLEXURAL REINFORCING - SOIL D Beam Type Length Width Height Midspan Reinf (bot) Midspan Reinf (top) End Reinf. (bot) End Reinf. (top) Special MRF 28' 30" 24" (2) #10's (2) #10's (5) #10's (5) #10's Special MRF 10' 30" 24" (2) #10's (2) #10's (4) #10's (4) #10's Intermediate MRF 28' 24" 28" (3) #8's (2) #10's (2) #8's (5) #10's Intermediate MRF 10' 24" 28" (2) #10's (2) #10's (2) #10's (3) #10's Table 6-2: Shear Reinforcing of Typical Beam Sections Soil D MRF BEAM SHEAR REINFORCING - SOIL D Beam Type Length Width Height Shear Reinf. (mid) Shear Reinf. (end) Special MRF 28' 30" 24" (2) #3 5" (3) #4 5" Special MRF 10' 30" 24" (4) #4 4" (4) #4 4" Intermediate MRF 28' 24" 28" (2) #3 8" (2) #3 6" Intermediate MRF 10' 24" 28" (2) #3 6" (2) #3 6" Table 6-3: Flexural Reinforcing of Typical Beam Sections Soil B MRF BEAM FLEXURAL REINFORCING - SOIL B Beam Type Length Width Height Midspan Reinf (bot) Midspan Reinf (top) End Reinf. (bot) End Reinf. (top) Special MRF 28' 26" 22" (2) #10's (2) #10's (5) #10's (5) #10's Special MRF 10' 26" 22" (2) #9's (2) #9's (4) #9's (4) #9's Intermediate MRF 28' 20" 26" (2) #9's (2) #9's (2) #9's (5) #9's Intermediate MRF 10' 20" 26" (2) #8's (2) #8's (2) #8's (2) #8's Table 6-4: Shear Reinforcing of Typical Beam Sections Soil B MRF BEAM SHEAR REINFORCING - SOIL B Beam Type Length Width Height Shear Reinf. (mid) Shear Reinf. (end) Special MRF 28' 26" 22" (2) #3 5" (3) #4 4" Special MRF 10' 26" 22" (4) #4 4" (4) #4 4" Intermediate MRF 28' 20" 26" (2) #3 8" (2) #3 5" Intermediate MRF 10' 20" 26" (2) #3 5" (2) #3 5" Table 6-5: Reinforcing of Typical Special MRF Column Sections Soil D SPECIAL MRF COLUMNS SOIL D Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 28"x28" (8) #10's (3) #4 4" (2) #3 6" Rem. Floors 12' 28"x28" (8) #9's (3) #4 4" (2) #3 6" Page 45

58 Table 6-6: Reinforcing of Typical Intermediate MRF Column Sections Soil D INTERMEDIATE MRF COLUMNS SOIL D Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 24"x24" (8) #8's (2) #3 9" (2) #3 14" Rem. Floors 12' 24"x24" (8) #8's (2) #3 9" (2) #3 14" Table 6-7: Reinforcing of Typical Special MRF Column Sections Soil B SPECIAL MRF COLUMNS SOIL B Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 24"x24" (8) #8's (3) #4 4" (2) #3 6" Rem. Floors 12' 24"x24" (8) #8's (3) #4 4" (2) #3 6" Table 6-8: Reinforcing of Typical Intermediate MRF Column Sections Soil B INTERMEDIATE MRF COLUMNS SOIL B Column Type Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 20"x20" (8) #7's (2) #3 9" (2) #3 18" Rem. Floors 12' 20"x20" (8) #7's (2) #3 9" (2) #3 18" Table 6-9: Reinforcing of Typical Office Building Gravity Columns GRAVITY COLUMNS - ALL OFFICE BUILDINGS Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 24"x24" (8) #7's (3) #4 4" (3) #3 5" Rem. Floors 12' 24"x24" (8) #7's (3) #4 4" (3) #3 5" 6.3 Residential Building Hilo Residential Building Design Tables 6-10 and 6-11 display the flexural and shear reinforcing details of typical elevator shear wall sections for the residential building. All shear walls for each building have a thickness of 10. The seismic force values of both the Hilo and Monterey building were again very similar, with the Monterey moment frame building having slightly larger seismic forces for Soil D, and the Hilo shear wall building having slightly larger seismic forces for Soil B. The Page 46

59 soil D special shear wall building was designed with the Monterey loads, and the soil B special shear wall building was designed with the Hilo loads. Due to the similarity of forces between the two cases, two different special moment frame designs were not necessary. The ordinary shear wall buildings were designed using the Waikiki seismic loads Hilo Residential Building Design Table 6-10: Reinforcing of Typical Special Elevator Shear Walls Soil D SPECIAL ELEVATOR SHEAR WALLS - SOIL D Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required 1st Floor Flange 132" 18" E.F. E.F. (16) #10's Y 1st Floor Web 336" 18" E.F. E.F. (4) #8's Y 2nd Floor Flange 132" 18" E.F. E.F. (10) #9's Y 2nd Floor Web 336" 18" E.F. E.F. (4) #7's Y Rem. Floors Flange 132" 18" E.F. E.F. (10) #7's N Rem. Floors Web 336" 18" E.F. E.F. (4) #6's N Table 6-11: Reinforcing of Typical Ordinary Elevator Shear Walls Soil D ORDINARY ELEVATOR SHEAR WALLS - SOIL D Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required 1st Floor Flange 132" 18" E.F. E.F. (16) #8's Y 1st Floor Web 336" 18" E.F. E.F. (4) #8's Y 2nd Floor Flange 132" 18" E.F. E.F. (10) #7's N 2nd Floor Web 336" 18" E.F. E.F. (4) #7's N Rem. Floors Flange 132" 18" E.F. E.F. (10) #6's N Rem. Floors Web 336" 18" E.F. E.F. (4) #6's N Page 47

60 Table 6-12: Reinforcing of Typical Special Stairwell Shear Walls Soil D SPECIAL STAIRWELL SHEAR WALLS - SOIL D Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required 1st Floor Flange 120" 12" E.F. E.F. (8) #10's Y 1st Floor Web 192" 18" E.F. E.F. (12) #10's Y 1st Floor Door Wall 146" 18" E.F. E.F. (8) #10's Y 2nd Floor Flange 120" 18" E.F. E.F. (6) #10's Y 2nd Floor Web 192" 18" E.F. E.F. (8) #10's Y 2nd Floor Door Wall 146" 18" E.F. E.F. (6) #10's Y 3rd Floor Flange 120" 18" E.F. E.F. (4) #10's Y 3rd Floor Web 192" 18" E.F. E.F. (4) #10's Y 3rd Floor Door Wall 146" 18" E.F. E.F. (4) #10's Y 4th Floor Flange 120" 18" E.F. E.F. (4) #7's N 4th Floor Web 192" 18" E.F. E.F. (4) #7's N 4th Floor Door Wall 146" 18" E.F. E.F. (4) #7's N Rem. Floors Flange 120" 18" E.F. E.F. (4) #6's N Rem. Floors Web 192" 18" E.F. E.F. (4) #6's N Rem. Floors Door Wall 146" 18" E.F. E.F. (4) #6's N Table 6-13: Reinforcing of Typical Ordinary Stairwell Shear Walls Soil D ORDINARY STAIRWELL SHEAR WALLS - SOIL D Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required 1st Floor Flange 120" 18" E.F. E.F. (4) #7's N 1st Floor Web 192" 18" E.F. E.F. (4) #7's N 1st Floor Door Wall 146" 18" E.F. E.F. (4) #7's N Rem. Floors Flange 120" 18" E.F. E.F. (4) #6's N Rem. Floors Web 192" 18" E.F. E.F. (4) #6's N Rem. Floors Door Wall 146" 18" E.F. E.F. (4) #6's N Table 6-14: Reinforcing of Typical Special Elevator Shear Walls Soil B SPECIAL ELEVATOR SHEAR WALLS - SOIL B Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required 1st Floor Flange 132" 18" E.F. E.F. (10) #10's Y 1st Floor Web 336" 18" E.F. E.F. (4) #7's Y 2nd Floor Flange 132" 18" E.F. E.F. (10) #8's N 2nd Floor Web 336" 18" E.F. E.F. (4) #6's N Rem. Floors Flange 132" 18" E.F. E.F. (10) #7's N Rem. Floors Web 336" 18" E.F. E.F. (4) #6's N Page 48

61 Table 6-15: Reinforcing of Typical Ordinary Elevator Shear Walls Soil B ORDINARY ELEVATOR SHEAR WALLS - SOIL B Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required All Floors Flange 132" 18" E.F. E.F. (10) #6's N All Floors Web 336" 18" E.F. E.F. (4) #6's N Table 6-16: Reinforcing of Typical Special Stairwell Shear Walls Soil B SPECIAL STAIRWELL SHEAR WALLS - SOIL B Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required 1st Floor Flange 120" 18" E.F. E.F. (8) #10's Y 1st Floor Web 192" 18" E.F. E.F. (12) #10's Y 1st Floor Door Wall 146" 18" E.F. E.F. (8) #10's Y 2nd Floor Flange 120" 18" E.F. E.F. (4) #10's Y 2nd Floor Web 192" 18" E.F. E.F. (4) #10's Y 2nd Floor Door Wall 146" 18" E.F. E.F. (4) #10's Y 3rd Floor Flange 120" 18" E.F. E.F. (4) #8's N 3rd Floor Web 192" 18" E.F. E.F. (4) #8's N 3rd Floor Door Wall 146" 18" E.F. E.F. (4) #8's N Rem. Floors Flange 120" 18" E.F. E.F. (4) #6's N Rem. Floors Web 192" 18" E.F. E.F. (4) #6's N Rem. Floors Door Wall 146" 18" E.F. E.F. (4) #6's N Table 6-17: Reinforcing of Typical Ordinary Stairwell Shear Walls Soil B ORDINARY STAIRWELL SHEAR WALLS - SOIL B Wall Type Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Required All Floors Flange 120" 18" E.F. E.F. (4) #6's N All Floors Web 192" 18" E.F. E.F. (4) #6's N All Floors Door Wall 146" 18" E.F. E.F. (4) #6's N Table 6-18: Reinforcing of Typical Residential Building Gravity Columns GRAVITY COLUMNS - ALL RESIDENTIAL BUILDINGS Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1st Floor 12' 20"x20" (8) #7's (3) #4 4" (3) #3 5" Rem. Floors 9' 20"x20" (8) #7's (3) #4 4" (3) #3 5" Page 49

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63 7 Tsunami Design Loads The lateral force resisting system of the building must be designed to resist hydrodynamic tsunami drag forces at each level, hydrodynamic drag component loads, and debris impact loads. From the Energy Grade Line Method analysis, it was determined that the maximum inundation depths to be used for design in Hilo and Waikiki would be 55 feet and 25 feet, respectively. The EGL method also determined that the maximum flow velocity to be used for design in Hilo and Waikiki would be 35.8 ft/s and 28 ft/s, respectively. With these maximum inundation depth and velocity values, the lateral tsunami loads for each building were calculated for each of the three load cases. Component loads were also calculated for the columns and walls of each of the buildings. See Table 7-1 for a summary of the design loads. 7.1 Overall Building Drag Force The overall tsunami building drag force was determined for the office and residential buildings for the Hilo, Waikiki, and Monterey locations using Equation 3-2. This force was then compared with the base shear due to seismic forces. Section of ASCE 7 Chapter 6 allows the overall building drag force to be compared to the Horizontal Seismic Load Effect, E mh. If F d > E mh, the overall building drag force must be considered for the structural design. The Horizontal Seismic Load Effect, E mh, includes 75 percent of the system s Overstrength Factor, Ω 0, for Seismic Design Category D, E, or F for the life safety performance level and is given by Equation 7-1. This provision applied to the buildings at Monterey and Hilo, which had Seismic Design Category D. Page 51

64 E mh = 0.75Ω o E h Equation 7-1: Horizontal Seismic Load Effect Including Overstrength Factor Table 7-1: Tsunami Loading Summary Office Building Residential Building Flow Parameters Hilo Waikiki Monterey Hilo Waikiki Monterey Max. Inundation Depth, h max (ft) Max. Flow Velocity, u max (fps) Overall Building Lateral Loading (kips) Load Case Load Case Load Case Hydrodynamic Drag Component Loading Exterior Column Hydrodynamic Drag (kips/ft) Interior Column Hydrodynamic Drag (kips/ft) Exterior Wall Hydrodynamic Drag (kips/ft) Interior Wall Hydrodynamic Drag (kips/ft) Exterior Wall Bore Force (kips/ft) Debris Loading Ext. Column Debris Impact (kips) Ext. Wall Debris Impact (kips) For Seismic Design Category A, B and C, the value of the seismic base shear must be directly compared to the overall building drag force. When comparing the tsunami loads to the seismic loads of each building, it was determined that the base shear due to tsunami loading was larger than the seismic base shear values at the Hilo and Waikiki locations. Therefore, overall building drag force had to be considered to redesign the members of the Page 52

65 buildings in Hilo and Waikiki. In the Hilo and Waikiki locations, Load Case 2 controlled the overall building drag force. In Monterey, Load Case 1 controlled the overall building drag force. 7.2 Component Drag Force Drag Force on Components The component hydrodynamic drag force was computed for components of each building. For the office building, the hydrodynamic component drag was calculated for the exterior moment frame columns and the interior gravity columns. Exterior columns experience increased drag due to debris blockage. Therefore, b was taken as the tributary width of the column multiplied by a closure ratio value of 0.7. For the residential building, the hydrodynamic drag was calculated for the broad side (web) of the elevator shear wall, the narrow side (flange) of the stairwell shear wall and the interior and exterior gravity columns Bore Loads on Vertical Structural Components The bore hydrodynamic load was calculated for the exterior facing elevator shear walls in the Waikiki residential building, due to the fringing reefs in Waikiki. In areas where bores are possible, the bore force must be calculated for vertical components with a width to inundation depth ratio of three or more. Therefore, the bore load on the elevator shear wall was calculated for an inundation depth of 9.33 feet (1/3 of the elevator wall width or 28 feet). 7.3 Debris Impact Loads The debris impact loads were calculated for design of components in each building. Because of their location away from shipping ports, the Waikiki and Monterey building sites Page 53

66 were not in impact zones for shipping containers. Therefore, only logs were considered using the simplified debris impact load from equation 3-6 reduced by 50%. Page 54

67 8 Tsunami Building Designs 8.1 Office Building Tsunami Designs Moment Frame Analysis ETABS was used to apply the tsunami overall building drag forces to the broad side of the moment frame building (Fig 8-1). Figure 8-1: ETABS Model of Special Moment Frame Building with Hilo Tsunami Overall Building Drag Force Page 55

68 Figure 8-2: ETABS North-South Special Moment Frame Column Moment Diagram Due to Hilo Tsunami Overall Building Drag Force The moment and shear values from ETABS were used to redesign the beams and columns in the north-south moment frames. RISA-2D was used to determine the moment and shear values due to component loading (which includes hydrodynamic drag component forces and impact forces) on structural members. For the moment frame building, only exterior and interior columns Page 56

69 were analyzed for component loading. Figure 8-3 shows an example of the hydrodynamic component loading and moment diagram of a portion of an exterior column on RISA-2D. Figure 8-3: RISA 2-D Special Moment Frame Column Moment Diagram Due to Hilo Tsunami Hydrodynamic Component Drag Force Beam Designs Tables 8-1 through 8-4 display the beam flexural and shear reinforcing designs due to the tsunami overall building drag force for the Hilo special moment frame. The overall building drag force resulted in larger beam moments and shears than the seismic moments and shears in the lower portion of the office building. The tsunami forces resulted in an increase in beam size for the first floor of the Hilo Soil Type D buildings and the first and second floors of the Hilo Soil Type B buildings. Reinforcing was also increased in various beams in the Hilo building. Due to the relatively small overall building drag forces in the Waikiki and Monterey buildings, redesign of the beams was not needed in those locations. Table 8-1: Hilo SMRF Beam Flexural Reinforcing Due to Overall Building Drag Force - Soil D HILO TSUNAMI BULDING FORCES SMF BEAM FLEXURAL REINFORCING - SOIL D Location Length Width Height Midspan Reinf (bot) Midspan Reinf (top) End Reinf. (bot) End Reinf. (top) 1st Floor - Typ. 28' 36" 32" (3) #10's [(2) #10's] (3) #10's [(2) #10's] (8) #10's [(5) #10's] (8) #10's [(5) #10's] 1st Floor - 10' Beam 10' 36" 32" (8) #10's [(2) #10's] (8) #10's [(2) #10's] (8) #10's [(4) #10's] (8) #10's [(4) #10's] 2nd Floor - Typ. 28' 30" 26" (2) #10's (2) #10's (5) #10's (8) #10's [(5) #10's] 2nd Floor - 10' Beam 10' 30" 26" (6) #10's [(2) #10's] (6) #10's [(2) #10's] (6) #10's [(4) #10's] (6) #10's [(4) #10's] Rem. Floors - Typ. 28' 30" 24" (2) #10's (2) #10's (5) #10's (6) #10's [(5) #10's] Rem. Floors - 10' Beam 10' 30" 24" (5) #10's [(2) #10's] (5) #10's [(2) #10's] (5) #10's [(4) #10's] (5) #10's [(4) #10's] Note: Reinforcing for seismic designed members in brackets [ ] Page 57

70 Table 8-2: Hilo SMRF Beam Flexural Reinforcing Due to Overall Building Drag Force - Soil B HILO TSUNAMI BUILDING FORCES SMF BEAM FLEXURAL REINFORCING - SOIL B Location Length Width Height Midspan Reinf (bot) Midspan Reinf (top) End Reinf. (bot) End Reinf. (top) 1st Floor - Typ. 28' 36" 32" (3) #10's [(2) #10's] (3) #10's [(2) #10's] (8) #10's [(5) #10's] (8) #10's [(5) #10's] 1st Floor - 10' Beam 10' 36" 32" (8) #10's [(2) #9's] (8) #10's [(2) #9's] (8) #10's [(4) #9's] (8) #10's [(4) #9's] 2nd Floor - Typ. 28' 30" 26" (2) #10's (2) #10's (5) #10's (8) #10's [(5) #10's] 2nd Floor - 10' Beam 10' 30" 26" (6) #10's [(2) #10's] (6) #10's [(2) #10's] (6) #10's [(4) #9's] (6) #10's [(4) #9's] Rem. Floors - Typ. 28' 26" 22" (2) #10's (2) #10's (5) #10's (5) #10's Rem. Floors - 10' Beam 10' 26" 22" (2) #10's (2) #10's (5) #10's [(4) #9's] (5) #10's [(4) #9's] Note: Reinforcing for seismic designed members in brackets [ ] Table 8-3: Hilo SMRF Beam Shear Reinforcing Due to Overall Building Drag Force - Soil D HILO TSUNAMI BULDING FORCES SMF BEAM SHEAR REINFORCING - SOIL D Beam Type Length Width Height Shear Reinf. (mid) Shear Reinf. (end) 1st Floor - Typ. 28' 36" 32" (2) #4 4" [(2) #3's@5"] (5) #3 4" [(3) #4's@5"] 1st Floor - 10' Beam 10' 36" 32" (6) #4 4" [(4) #4's@4"] (6) #4 4" [(4) #4's@4"] Rem. Floors - Typ. 28' 30" 26" (2) #4 6" [(2) #3's@5"] (4) #4 5" [(3) #4's@5"] Rem. Floors - 10' Beam 10' 30" 26" (5) #4 4" [(4) #4's@4"] (5) #4 4" [(4) #4's@4"] Rem. Floors - Typ. 28' 30" 24" (2) #4 6" [(2) #3's@5"] (4) #4 5" [(3) #4's@5"] Rem. Floors - 10' Beam 10' 30" 24" (5) #4 4" [(4) #4's@4"] (5) #4 4" [(4) #4's@4"] Note: Reinforcing for seismic designed members in brackets [ ] Table 8-4: Hilo SMRF Beam Shear Reinforcing Due to Overall Building Drag Force - Soil B HILO TSUNAMI BULDING FORCES SMF BEAM SHEAR REINFORCING - SOIL B Beam Type Length Width Height Shear Reinf. (mid) Shear Reinf. (end) 1st Floor - Typ. 28' 36" 32" (2) #4 4" [(2) #3's@5"] (5) #3 4" [(3) #4's@4"] 1st Floor - 10' Beam 10' 36" 32" (6) #4 4" [(4) #4's@4"] (6) #4 4" [(4) #4's@4"] 2nd Floor - Typ. 28' 30" 26" (2) #4 6" [(2) #3's@5"] (4) #4 5" [(3) #4's@4"] 2nd Floor - 10' Beam 10' 30" 26" (5) #4 4" [(4) #4's@4"] (5) #4 4" [(4) #4's@4"] Rem. Floors - Typ. 28' 26" 22" (2) #3 5" [(2) #3's@5"] (3) #4 4" [(3) #4's@4"] Rem. Floors - 10' Beam 10' 26" 22" (4) #4 4" [(4) #4's@4"] (4) #4 4" [(4) #4's@4"] Note: Reinforcing for seismic designed members in brackets [ ] Column Designs Tables 8-5 through 8-7 display the beam flexural and shear reinforcing designs due to the tsunami overall building drag force for the Hilo and Waikiki moment frames. Because the building was oriented such that the broad side faces the flow, the columns in the northsouth moment frames were designed with the overall building drag force as indicated in Figure 8-4. Page 58

71 Figure 8-4: Location of Moment Frame Columns Affected by Overall Building Drag Force The tsunami forces resulted in an increase in moment frame column size for the first floor of the Hilo Soil Type D buildings and the first and second floors of the Hilo Soil Type B buildings. Flexural reinforcement was also increased in several columns in the Hilo building. Moment frame column size and reinforcing also needed increasing in the first floor of the Oahu Soil Type B building. However, the columns in the Oahu Soil Type D columns were adequate for tsunami building forces. Due to the relatively small overall building drag forces in the Monterey building redesign of the columns was not needed. Table 8-5: Hilo SMRF Column Reinforcing Due to Overall Building Drag Force - Soil D HILO SPECIAL MRF COLUMNS SOIL D, TSUNAMI BUILDING FORCES Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 36"x36" (24) #10's [(8) #10's] (5) [(3) #4's@4"] (5) [(2) #3's@6"] 2 12' 30"x30" (16) #10's [(8) #9's] (4) [(3) #4's@4"] (3) [(2) #3's@6"] Rem. Floors 12' 28"x28" (8) #9's (3) 4" (3) 6" Note: Reinforcing for seismic designed members in brackets [ ] Page 59

72 Table 8-6: Hilo SMRF Column Reinforcing Due to Overall Building Drag Force - Soil B HILO SPECIAL MRF COLUMNS SOIL B, TSUNAMI BUILDING FORCES Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 36"x36" (24) #10's [(8) #8's] (5) [(3) #4's@4"] (5) [(2) #3's@6"] 2 12' 30"x30" (16) #10's [(8) #8's] (4) [(3) #4's@4"] (3) [(2) #3's@6"] Rem. Floors 12' 24"x24" (8) #8's (3) 4" (3) 6" Note: Reinforcing for seismic designed members in brackets [ ] OAHU INTERMEDIATE MRF COLUMNS SOIL B, TSUNAMI BUILDING FORCES Floor Height Size Longitudinal Reinf. Boundary Reinf. Shear Reinf. 1 14' 24"x24" (8) #8's [(8) #7's] (2) 9" (2) [(2) #3's@18"] Rem. Floors 12' 20"x20" (8) #7's (2) 9" (2) 18" Table 8-7: Waikiki IMRF Column Reinforcing Due to Overall Building Drag Force - Soil B OAHU INTERMEDIATE MRF COLUMNS SOIL B, TSUNAMI BUILDING FORCES Floor Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. 1 14' 24" (8) #8's [(8) #7's] (2) 9" (2) [(2) #3's@18"] Rem. Floors 12' 20" (8) #7's (2) 9" (2) 18" Note: Reinforcing for seismic designed members in brackets [ ] Tables 8-8 through 8-11 display the beam flexural and shear reinforcing designs due to the tsunami component forces for the Hilo and Waikiki moment frames. Because the building was oriented such that the broad side faces the flow, the columns on the broad side of the building, as indicated in Figure 8-5, are exposed to component forces. Page 60

73 Figure 8-5: Hilo SMRF Beam Flexural Reinforcing Due to Tsunami Building Forces - Soil D Therefore, the columns on the broad side of the building were designed with either the hydrodynamic drag component force or the impact force, whichever was larger. Because the corner columns are both exposed to component forces and are also part of the moment frame that resists overall building forces, the corner columns were designed based on the controlling loading between the overall building force and the component forces. Several columns in both the Hilo and Waikiki buildings needed an increase in reinforcement due to the tsunami component forces. The columns in the Monterey building were adequate for hydrodynamic component forces. Table 8-8: Hilo SMRF Column Reinforcing Due to Tsunami Component Forces - Soil D HILO SPECIAL MRF COLUMNS SOIL D, TSUNAMI COMPONENT FORCES Floor Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. Controlling Load 1 14' 28" (16) #10's [(8) #10's] (4) 4" [(3) #4's@4"] (3) 4" [(2) #3's@6"] HYDRODYNAMIC 2 AND 3 12' 28" (12) #10's [(8) #9's] (4) 4" [(3) #4's@4"] (3) 4" [(2) #3's@6"] HYDRODYNAMIC Rem. Floors 12' 28" (8) #10's [(8) #9's] (3) 4" [(3) #4's@4"] (3) 4" [(2) #3's@6"] IMPACT Note: Reinforcing for seismic designed members in brackets [ ] Page 61

74 Table 8-9: Waikiki IMF Column Reinforcing Due to Tsunami Component Forces - Soil D OAHU INTERMEDIATE MRF COLUMNS SOIL D, TSUNAMI COMPONENT FORCES Floor Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. Controlling Load 1 14' 24" (8) #8's (3) 5" [(3) #3's@9"] (3) 4" [(2) #3's@14"] HYDRODYNAMIC 2 12' 24" (8) #8's (3) 5" [(3) #3's@9"] (3) 4" [(2) #3's@14"] HYDRODYNAMIC Rem. Floors 12' 24" (8) #7's (2) 9" (2) 14" SEISMIC Note: Reinforcing for seismic designed members in brackets [ ] Table 8-10: Hilo SMRF Column Reinforcing Due to Tsunami Component Forces - Soil B HILO SPECIAL MRF COLUMNS SOIL B, TSUNAMI COMPONENT FORCES Floor Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. Controlling Load 1 14' 28" (16) #10's [(8) #8's] (4) 4" [(3) #4's@4"] (3) 4" [(2) #3's@6"] HYDRODYNAMIC 2 AND 3 12' 28" (12) #10's [(8) #8's] (4) 4"[(3) #4's@4"] (3) 4" [(2) #3's@6"] HYDRODYNAMIC Rem. Floors 12' 24" (8) #8's (3) 5" [(3) #4's@4"] (3) 5" [(2) #3's@6"] IMPACT Note: Reinforcing for seismic designed members in brackets [ ] Table 8-11: Waikiki IMRF Column Reinforcing Due to Tsunami Component Forces - Soil B OAHU INTERMEDIATE MRF COLUMNS SOIL B, TSUNAMI COMPONENT FORCES Column Type Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. Controlling Load 1 14' 24" (8) #8's [(8) #7's] (3) 5" [(2) #3's@9"] (3) 4" [(2) #3's@18"] HYDRODYNAMIC 2 12' 24" (8) #8's [(8) #7's] (3) 5" [(2) #3's@9"] (3) 4" [(2) #3's@18"] HYDRODYNAMIC Rem. Floors 12' 20" (8) #7's (2) 9" (2) 18" SEISMIC Note: Reinforcing for seismic designed members in brackets [ ] Figures 8-6 and 8-7 show the typical first floor beam reinforcement layouts for the seismic designed Hilo Soil D building and the tsunami designed Hilo building, respectively. Each figure has the beam reinforcing layout for the boundary and the midspan of the beam. Page 62

75 Figure 8-6: Boundary reinforcing (left) and midspan reinforcing (right) for the Hilo Seismic Soil D first floor moment frame beams. Figure 8-7: Boundary reinforcing (left) and midspan reinforcing (right) for the Hilo Tsunami Overall Building Drag Force first floor moment frame beams. Figures 8-8 and 8-9 show the typical first floor column reinforcement layouts for the seismic designed Hilo Soil D building and the Hilo tsunami designed building, respectively. The figures display the boundary column reinforcing layout. Page 63

76 Figure 8-8: Boundary reinforcing the Hilo Seismic Soil D first floor moment frame columns. Figure 8-9: Boundary reinforcing for the Hilo Tsunami Overall Building Drag Force first floor moment frame columns. 8.2 Residential Building Tsunami Designs Shear Wall Analysis ETABS was used to apply the tsunami overall building drag forces to the broad side of the shear wall building (Fig 8-10). Page 64

77 Figure 8-10: ETABS Model of Special Shear Wall Building with Hilo Tsunami Overall Building Drag Force The moment and shear values from ETABS were used to redesign the elevator shear walls, which provide the main resistance against lateral loads perpendicular to the broad side of the building. Figure 8-11 shows the ETABS moment distribution on an elevator shear wall caused by the overall building drag force. Page 65

78 Figure 8-11: ETABS Stairwell Shear Wall Moment Diagram Due to Hilo Tsunami Overall Building Drag Force RISA-2D was used to determine the moment and shear values due to component loading (which includes hydrodynamic drag component forces and impact forces) on structural members. For the shear wall building, exterior columns, interior columns, and the exterior portion of the elevator shear walls were analyzed for component loading. For analysis of the elevator shear walls, the load was determined for a one-foot width section of the wall. Figure 8-12 shows an example the hydrodynamic component loading and moment diagram of a portion of the exterior elevator shear wall on RISA-2D. Page 66

79 Figure 8-12: RISA 2-D 12 Width Elevator Shear Wall Segment Moment Diagram Due to Hilo Tsunami Hydrodynamic Component Drag Force Elevator Shear Wall Designs Tables 8-12, 8-13, and 8-14 display the shear wall flexural and shear reinforcing designs due to the tsunami component forces for the Hilo, Waikiki, and Monterey elevator shear walls. Because the building was oriented such that the broad side faces the flow, the shear walls on the exterior of the building were designed with component forces. It was determined that the debris impact loads controlled over the hydrodynamic component drag forces. The vertical reinforcing was increased in the exterior (web) portion of the elevator shear walls to resist out of plane bending. The width of this portion of the wall was also increased from 10 to 12 to help resist out of plane shear. Due to the out of plane shear force in the exterior portion of the elevator shear walls due to component forces, the original shear wall design would fail in shear. Therefore, headed shear studs are needed to resist the out of plane shear forces due to components on the exterior portion of the elevator walls. For the tsunami component design of the exterior (web) portion of the elevator shear walls, note that the horizontal reinforcing, boundary reinforcing, and tie reinforcing do not change from the seismic designed shear walls. Therefore, those respective columns have been left out of Tables 8-12, 8-13, and Page 67

80 Table 8-12: Hilo Special Elevator Shear Wall Reinforcing Due to Tsunami Component Forces HILO SPECIAL ELEVATOR SHEAR WALL- TSUNAMI COMPONENT FORCES (DEBRIS IMPACT CONTROL) Location Portion Length Width Vert. Reinf. Headed Studs Stud Row Spacing All Floors Flange 132" 10" No Change n/a n/a 1st Floor Web 336" 12" 10" E.F. E.F.] 4" 12" 2nd Floor Web 336" 12" 10" E.F. E.F.] 4" 12" Rem. Floors Web 336" 12" 10" E.F. E.F.] 4" 12" Note: Reinforcing for seismic designed members in brackets [ ] Table 8-13: Waikiki Elevator Shear Wall Reinforcing Due to Tsunami Component Forces WAIKIKI ORDINARY ELEVATOR SHEAR WALL - TSUNAMI COMPONENT FORCES (DEBRIS IMPACT CONTROL) Location Portion Length Width Vert. Reinf. Headed Studs Stud Row Spacing All Floors Flange 132" 10" No Change n/a n/a 1st Floor Web 336" 12" 16" E.F. E.F.] 5" 12" 2nd Floor Web 336" 12" 16" E.F. E.F.] 5" 12" 3rd Floor Web 336" 12" 16" E.F. E.F.] 5" 12" Rem. Floors Web 336" 12" No Change n/a n/a Note: Reinforcing for seismic designed members in brackets [ ] Table 8-14: Monterey Elevator Shear Wall Reinforcing Due to Tsunami Component Forces MONTEREY SPECIAL ELEVATOR SHEAR WALL - TSUNAMI COMPONENT FORCES (DEBRIS IMPACT CONTROL) Location Portion Length Width Vert. Reinf. Headed Studs Stud Row Spacing All Floors Flange 132" 10" No Change n/a n/a 1st Floor Web 336" 12" 16" E.F. E.F.] 5" 12" 2nd Floor Web 336" 12" 16" E.F. E.F.] 5" 12" Rem. Floors Web 336" 12" No Change n/a n/a Note: Reinforcing for seismic designed members in brackets [ ] Figures 8-13 and 8-14 show the typical first floor elevator shear wall reinforcement layouts for the seismic designed Hilo Soil D building and the tsunami designed Hilo building, respectively. Page 68

81 Figure 8-13: Reinforcing for the Hilo Seismic Soil D first floor elevator shear walls. Figure 8-14: Reinforcing for the Hilo Tsunami Component Force first floor elevator shear walls Stairwell Shear Wall Designs Table 8-15 displays the shear wall flexural and shear reinforcing designs due to the tsunami overall building drag forces for the Hilo special stairwell shear walls. Because the building was oriented such that the broad side faces the flow, the stairwell shear walls on the east and west side of the building was designed to resist the overall building drag forces. The seismic designs of the Waikiki ordinary stairwell and the Monterey special shear wall are adequate to resist tsunami overall building forces. Page 69

82 Table 8-15: Hilo Special Stairwell Shear Wall Due to Overall Building Drag Force Soil D HILO SPECIAL STAIRWELL SHEAR WALL - TSUNAMI BUILDING FORCES - SOIL D Location Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Req'd 1st Floor Flange 120" (2) 12" E.F. E.F. (14) #10's [(8) #10's] Y 1st Floor Web 192" 12" E.F. 18" E.F.] E.F. E.F.] (24) #10's [(12) #10's] Y 1st Floor Door Wall 146" 12" E.F. 18" E.F.] E.F. E.F.] (14) #10's [(8) #10's] Y 2nd Floor Flange 120" 18" E.F. E.F. (6) #10's Y 2nd Floor Web 192" 18" E.F. E.F. E.F.] (8) #10's Y 2nd Floor Door Wall 146" 18" E.F. E.F. E.F.] (6) #10's Y 3rd Floor Flange 120" 18" E.F. 18" E.F.] E.F. (6) #10's [(4) #10's] Y 3rd Floor Web 192" 18" E.F. 18" E.F.] E.F. (8) #10's [(4) #10's] Y 3rd Floor Door Wall 146" 18" E.F. 18" E.F.] E.F. (6) #10's [(4) #10's] Y 4th Floor Flange 120" 18" E.F. 18" E.F.] E.F. (6) #10's [(4) #7's] Y [N] 4th Floor Web 192" 18" E.F. 18" E.F.] E.F. (8) #10's [(4) #7's] Y [N] 4th Floor Door Wall 146" 18" E.F. 18" E.F.] E.F. (6) #10's [(4) #7's] Y [N] Rem. Floors Flange 120" 18" E.F. 18" E.F.] E.F. (6) #10's [(4) #6's] Y [N] Rem. Floors Web 192" 18" E.F. 18" E.F.] E.F. (8) #10's [(4) #6's] Y [N] Rem. Floors Door Wall 146" 18" E.F. 18" E.F.] E.F. (6) #10's [(4) #6's] Y [N] Note: Reinforcing for seismic designed members in brackets [ ] Table 8-16: Hilo Special Stairwell Shear Wall Due to Overall Building Drag Force Soil B HILO SPECIAL STAIRWELL SHEAR WALL - TSUNAMI BUILDING FORCES - SOIL B Location Portion Length Vert. Reinf. Horiz. Reinf. Boundary Vert. Reinf. Ties Req'd 1st Floor Flange 120" (2) 12" E.F. E.F. E.F.] (14) #10's [(8) #10's] Y 1st Floor Web 192" 12" E.F. 18" E.F.] E.F. E.F.] (24) #10's [(12) #10's] Y 1st Floor Door Wall 146" 12" E.F. 18" E.F.] E.F. E.F.] (14) #10's [(8) #10's] Y 2nd Floor Flange 120" 18" E.F. E.F. E.F.] (6) #10's [(4) #10's] Y 2nd Floor Web 192" 18" E.F. E.F. E.F.] (8) #10's [(4) #10's] Y 2nd Floor Door Wall 146" 18" E.F. E.F. E.F.] (6) #10's [(4) #10's] Y 3rd Floor Flange 120" 18" E.F. 18" E.F.] E.F. E.F.] (6) #10's [(4) #8's] Y [N] 3rd Floor Web 192" 18" E.F. 18" E.F.] E.F. E.F.] (8) #10's [(4) #8's] Y [N] 3rd Floor Door Wall 146" 18" E.F. 18" E.F.] E.F. E.F.] (6) #10's [(4) #8's] Y [N] Rem. Floors Flange 120" 18" E.F. 18" E.F.] E.F. E.F.] (6) #10's [(4) #6's] Y [N] Rem. Floors Web 192" 18" E.F. 18" E.F.] E.F. E.F.] (8) #10's [(4) #6's] Y [N] Rem. Floors Door Wall 146" 18" E.F. 18" E.F.] E.F. E.F.] (6) #10's [(4) #6's] Y [N] Note: Reinforcing for seismic designed members in brackets [ ] External Gravity Column Designs Tables 8-17 and 8-18 display the gravity column flexural and shear reinforcing designs due to the tsunami component forces for the Hilo and Waikiki buildings. Because the building was oriented such that the broad side faces the flow, the gravity on the exterior of the building were designed with component forces. It was determined that the gravity columns on the interior of the building would not need to be redesigned due to small Page 70

83 hydrodynamic component forces on the interior columns. The original design of the Monterey gravity columns was adequate to resist tsunami component forces. Table 8-17: Hilo Residential Building Exterior Gravity Column Reinforcing Due to Tsunami Component Forces EXTERIOR GRAVITY COLUMNS - HILO RESIDENTIAL BUILDING (TSUNAMI COMPONENT LOADING) Column Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. Load Type 1st Floor 12' 24" (12) #10's [(8) #7's] (4) 4" [(3) #4's@4"] (3) 5" [(3) #3's@5"] Hydrodynamic 2nd Floor 9' 24" (12) #9's [(8) #7's] (4) 4" [(3) #4's@4"] (3) 5" [(3) #3's@5"] Hydrodynamic Rem. Floors 9' 24" (12) #8's [(8) #7's] (3) 4" [(3) #4's@4"] (3) 5" [(3) #3's@5"] Impact Note: Reinforcing for seismic designed members in brackets [ ] Table 8-18: Oahu Residential Building Exterior Gravity Column Reinforcing Due to Tsunami Component Forces EXTERIOR GRAVITY COLUMNS - OAHU RESIDENTIAL BUILDING (TSUNAMI COMPONENT LOADING) Column Height Size Flexural Reinf. Boundary Reinf. Shear Reinf. LOAD TYPE 1st Floor 12' 22" (12) #8's [(8) #7's] (3) #5 4" (3) 5" [(3) #3's@5"] Hydrodynamic 2nd Floor 9' 20" (8) #8's [(8) #7's] (3) #4 4" (3) 5" [(3) #3's@5"] Hydrodynamic Rem. Floors 9' 20" (8) #7's (3) #4 4" (3) 5" Seismic Note: Reinforcing for seismic designed members in brackets [ ] Page 71

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85 9 Material Quantity Comparison 9.1 Material Quantity Comparison Tables 9-1 and 9-2 display the amount of concrete and steel required for the seismic designed buildings and the tsunami designed buildings. The increase in volume of concrete between the seismic buildings and tsunami buildings were minimal. However, the designs for all buildings needed an increase in reinforcement tonnage for the tsunami designs. Table 9-1: Concrete Quantity Comparison Concrete Quantity Comparison Building Seis. Conc Vol. (CY) TSU Conc Vol. (CY) % Increase Hilo Special Moment Frame - D Hilo Special Moment Frame - B Intermediate Moment Frame - D Intermediate Moment Frame - B Monterey Special Moment Frame - D Monterey Special Moment Frame - B Hilo Special Shear Wall - D Hilo Special Shear Wall - B Ordinary Shear Wall - D Ordinary Shear Wall - B Monterey Special Shear Wall - D Monterey Special Shear Wall - B Page 73

86 Table 9-2: Reinforcement Quantity Comparison Reinforcing Steel Quantity Comparison Building Seis. Reinf. Wt (Ton) TSU Reinf. Wt (Ton) % Increase Hilo Special Moment Frame - D Hilo Special Moment Frame - B Intermediate Moment Frame - D Intermediate Moment Frame - B Monterey Special Moment Frame - D Monterey Special Moment Frame - B Hilo Special Shear Wall - D Hilo Special Shear Wall - B Ordinary Shear Wall - D Ordinary Shear Wall - B Monterey Special Shear Wall - D Monterey Special Shear Wall - B For the Hilo special moment frame buildings, an increase concrete volume of 2.3% and 8.8% was required for the tsunami design of the Soil D and Soil B buildings, respectively. An increase of reinforcement weight of 22.2% and 27.5% was also required for the tsunami design of the Soil D and Soil B moment frame buildings, respectively. The increase of concrete volume between both Hilo special shear wall buildings was only 2.2%. However, an increase in reinforcement weight of 38.3% and 39.9% was also required for the tsunami design of the Soil D and Soil B shear wall buildings, respectively. Much of the reinforcement increase was due to the significant increase in reinforcing required for the exterior portion of the elevator shear walls due to impact loads. For the Waikiki intermediate moment frame buildings, an increase concrete volume of 1.86% and 7.37% was required for the tsunami design of the Soil D and Soil B buildings, respectively. An increase in reinforcement weight of 3.21% and 4.24% was also required for the tsunami design of the Soil D and Soil B moment frame buildings, respectively. The increase of concrete volume between both Waikiki ordinary shear wall buildings was only 0.12%. However, an increase in reinforcement weight of 8.41% and 10.4% was also Page 74

87 required for the tsunami design of the Soil D and Soil B shear wall buildings, respectively. The increases in concrete and reinforcement were smaller in the Waikiki buildings than in the Hilo buildings due to the smaller tsunami forces in the Waikiki location. Due to the relatively low tsunami forces in Monterey, there was no difference in concrete or reinforcement volume in the moment frame building. There was also a minimal increase in concrete in the Monterey shear wall building. However, an increase in reinforcing weight of 7.24% and 5.53% was required for the tsunami design of the Soil D and Soil B shear wall buildings, respectively. This increase in reinforcement was primarily due to the impact forces on the exterior shear walls and the exterior gravity columns on the lower floors of the Monterey residential building. Page 75

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89 10 Conclusions After analyzing these prototype buildings for tsunami loads, the following conclusions were made: Tsunami forces resulted in redesign for members in Waikiki and Hilo buildings. For the Monterey buildings, no redesign was required for the moment frame building and minimal redesign was needed for the shear wall building. The increase in concrete volume was small for each building analyzed. The greatest required increase of concrete volume for the moment frame buildings due to tsunami forces was 8.8%. For the shear wall buildings, the greatest required concrete volume increase was 1.99%. An increase in reinforcing weight of 7.24% and 5.53% was required for the tsunami design of the Monterey Soil D and Soil B special shear wall buildings, respectively. An increase of reinforcement weight of 22.2% and 27.5% was also required for the tsunami design of the Soil D and Soil B moment frame buildings, respectively. In the lower floors of the building, column and beam size were greatly increased due to overall building drag forces. Impact loading on the Hilo and Waikiki exterior elevator shear walls resulted in an increase of wall thickness, an increase in longitudinal steel and also required the addition of shear studs. An increase in reinforcement weight of 38.3% and 39.9% was required for the tsunami design of the Hilo Soil D and Soil B shear wall buildings, respectively. Page 77

90 Due to out of plane tsunami impact forces from shipping containers, the exterior portion of the elevator shear wall required an increase in thickness of 2 and the addition of shear headed studs. In, Waikiki, an increase in reinforcement weight of 3.21% and 4.24% was also required for the tsunami design of the Soil D and Soil B intermediate moment frame buildings, respectively. An increase in reinforcement weight of 8.41% and 10.4% was also required for the tsunami design of the Waikiki Soil D and Soil B ordinary shear wall buildings, respectively. The addition of shear headed studs was required for the inundated floors of the shear wall buildings due to out of plane impact forces. Page 78

91 11 References ACI, 2011, Building Code Requirements for Structural Concrete, American Concrete Institute, Farmington Hills, Michigan ASCE, 2010, Minimum Design Loads for Buildings and Other Structures, American Society of Civil Engineers, Reston, Virginia. ASCE, 2014, ASCE 7 Chapter 6 Draft Tsunami Loads and Effects, ASCE 7 Tsunami Loads and Effects Subcommittee. CAEE, 2005, The December 26, 2004 Sumatra Earthquake and Tsunami, The Canadian Association for Earthquake Engineering, The University of Ottawa, Ottawa, ON, Canada. CCH Department of Planning and Permitting of Honolulu Hawai'i. City and County of Honolulu Building Code. Chapter 16 Article 11 Chock, G., Robertson, I.N., Kriebel D., Francis, M., and Nistor, I., 2011, Tohoku Japan Tsunami of March 11, 2011 Performance of Structures, American Society of Civil Engineers Structural Engineering Institute. FEMA Coastal Construction Manual. FEMA 55, Federal Emergency Management Agency FEMA, 2008, Guidelines for Design of Structures for Vertical Evacuation from Tsunamis, FEMA P646 Report, Federal Emergency Management Agency, Washington D.C. Ghosh, S.K., and David A. Fanella (2003). Seismic and Wind Design of Concrete Buildings. Illinois: Country Club Hills IBC, 2012, International Building Code, International Code Council, Country Club Hills, Illinois. Mikhaylov, Y. and Robertson, I., 2009, Evaluation of Prototypical Reinforced Concrete Building Performance When Subjected to Tsunami Loading, Research Report UHM/CEE/09-01, University of Hawai i at Mānoa, Honolulu, Hawai i. ( Mohamed, A., 2008, Characterization of Tsunami-Like Bores in Support of Loading on Structures, University of Hawai i at Mānoa, Honolulu, Hawai i. Pacheco, K. and Robertson, I., 2005, Evaluation of Tsunami Loads and Their Effect on Reinforced Concrete Buildings, Research Report UHM/CEE/05-06, University of Hawai i at Mānoa, Honolulu, Hawai i. ( Page 79

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93 Appendix A Hilo Tsunami Design Loads Sample Calculation Prototype Concrete Buildings - Hilo 6-Story Office Building Special Moment Resisting Frame on perimeter and interior frames; interior gravity columns with posttensioned floor slabs Seismic Design Criteria: S s = 1.5, S 1 = 0.6; Seismic site class D; R = 8, o = 3, C d = 5.5 Tsunami Risk Category II building located in Tsunami Design Zone per Figure Mean height above grade plane = 74 ft > 65 ft, therefore tsunami design is required (per Section 6.1.1a). 7-Story Residential Building Building Frame System with special reinforced concrete shear walls at exit stairs and elevator core, with concrete floor slabs on gravity columns Seismic Design Criteria: S s = 1.5, S 1 = 0.6; Seismic site class D; R = 6, o = 2.5, C d = 5 Tsunami Risk Category II building located in Tsunami Design Zone per Figure Mean height above grade plane = 66 ft > 65 ft, therefore tsunami design is required (per Section 6.1.1a) Assumed Conditions A. Building oriented with longitudinal axis parallel to shoreline. B. Building has no basement. C. Foundation system is deep piles with pile caps supporting all shear walls and all exterior columns. D. Ground floor slab on grade with isolation joints at columns. E. Top of first floor windows 8 ft. above grade (window sill at 3 ft). F. Section Tsunami Bores: Shall be considered where any of the following conditions exist: 1. Prevailing nearshore bathymetric slope is 1/100 or milder Does not apply 2. Shallow fringing reefs or other similar step discontinuities Does not apply 3. Where historically documented Applies 4. As described in the Recognized Literature Does not apply 5. As determined by a site-specific inundation analysis not required for these buildings Therefore bore loading must be considered in this design. G. Section Debris Impact Loads: Subject to shipping containers, ships or barges. H. Exterior cladding spans vertically between floors. Page 81

94 Tsunami Loading Summary Table gives a summary of the tsunami loads determined for each of the two buildings located at each of the selected sites. Note that these values include the loading values for the Monterey and Waikiki locations. This sample calculation will only use the loading values for the Hilo location. Table 1: Summary of Tsunami Loading for Office and Residential Buildings Office Building Residential Building Flow Parameters Hilo Waikiki Monterey Hilo Waikiki Monterey Max. Inundation Depth, h max (ft) Max. Flow Velocity, u max (fps) Overall Building Lateral Loading (kips) Load Case Load Case Load Case Hydrodynamic Drag Component Loading Exterior Column Hydrodynamic Drag (kips/ft) Interior Column Hydrodynamic Drag (kips/ft) Exterior Wall Hydrodynamic Drag (kips/ft) Interior Wall Hydrodynamic Drag (kips/ft) Exterior Wall Bore Force (kips/ft) Debris Loading Exterior Column Debris Impact (kips) Exterior Wall Debris Impact (kips) Page 82

95 Overall Building Forces Tsunami Design for Hilo Office Building Section defines the following three Load Cases, which must be considered in the design. Load Case 1: Maximum buoyancy and associated hydrodynamic drag. The exterior inundation depth need not exceed the lesser of h ext < h max = 55.0 ft < 10 ft < top of first story windows = 8 ft. CONTROLS Because the ground floor consists of a slab-on-grade that is isolated from the building columns, any uplift pressures developed below the slab will cause localized slab failure but will not result in buoyancy of the building. Therefore overall buoyancy is not a consideration. For the sake of illustration, if we had assumed that the ground floor consists of structural grade beams and integral slab on grade without isolation joints, and that the soil allowed ground water pressure increase below the building (ie. sandy or gravely subsoil), the buoyancy would need to be considered as follows: Section 6.9.1, Eqn Apply load combination: 0.9D + F TSU H TSU F v = γ s V w = (1.1x64.0)(254 x 88 x 8 )/1000 = 12,588 kips where H TSU = 0 since scour is assumed uniform around the building perimeter. and building dead weight, D = 25,100 kips, including foundation. Therefore net uplift = x 25, ,588 = kips, downward. Overall uplift would therefore not be a concern, even if the ground floor were a structural slab capable of resisting the associated buoyancy pressures. This example also ignores any uplift resistance provided by the deep foundations. In combination with buoyancy, Load Case 1 requires application of the associated hydrodynamic drag on the entire building. Section , Eqn gives F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) Where s = 1.1 x 2.0 = 2.2 slugs/cuft I tsu = 1.0 (Table TRC II) C d = 1.45 (Table based on B/h sx = 254/8 = 31.8) C cx = 1.0 since the exterior walls are assumed to be intact for Load Case 1 B = 254 overall width of building h = 8 Figure is used to determine the flow velocity corresponding to an inundation depth of 8 ft. For h = 8, h/h max = 8/55.0 = Identifying this point on the inflow side of Figure 6.8-1(a) indicates that this inundation depth occurs at t/(t TSU ) = At the same time in Figure 6.8-1(b) the flow velocity ratio is u/u max = Therefore the flow velocity is u = 0.6 x 35.8 = fps. So F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) = ( )/1000 = 1495 kips This load is compared with the seismic base shear to determine if the lateral force resisting system has ample capacity to resist the overall tsunami loads. For the redesign of the lateral force resisting Page 83

96 system, if needed, the force is distributed to each inundated floor and is applied to an ETABS model. Load Case 2: Maximum Flow Velocity According to Figure 6.8-1, LC2 occurs when the inundation depth is 2/3h max = 2/3 x 55.0 = ft. Section , Eqn gives F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) Where all parameters are the same as for LC1 except: C d = 1.25 (Table based on B/h sx = 254/36.67 = 6.93) C cx(typ) = (A col+a wall )+1.5A beam = (( ) ) = < 0.7 Bh sx Therefore C cx = 0.7 controls per Section Due to differing floor heights, the Ccx calculation was repeated for all floors. The Ccx value of the top inundated floor is also different due to the fact that the top inundated floor is only partially inundated by the tsunami. It was determined that Ccx = 0.7 controlled for all floors. For simplicity, only the Ccx calculation for the typical floor is shown. h = ft. u = u max = 35.8 fps So F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) = ( )/1000 = kips This load is compared with the seismic base shear to determine if the lateral force resisting system has ample capacity to resist the overall tsunami loads. For the redesign of the lateral force resisting system, if needed, the force is distributed to each inundated floor and is applied to an ETABS model. Load Case 3: Maximum Inundation Depth According to Figure 6.8-1, LC3 occurs when the inundation depth is h max = 55.0 ft. and the flow velocity is 1/3u max = 1/3 x 35.8 = fps. Section , Eqn gives F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) All other parameters are the same as LC2 parameters. So F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) = ( )/1000 = 1914 kips This load is compared with the seismic base shear to determine if the lateral force resisting system has ample capacity to resist the overall tsunami loads. For the redesign of the lateral force resisting system, if needed, the force is distributed to each inundated floor and is applied to an ETABS model. Although LC3 does not control design of the lateral force resisting system, the intent of LC3 is to ensure evaluation of components up to the maximum inundation depth. Evaluation of Lateral Force Resisting System Because the structure has been designed for Seismic Design Category D, Section permits the use of 0.75 o E h to evaluate the lateral force resisting system (LFRS), where E h is the seismic base shear. From the seismic design of this structure, E h = 2,435 kips. Therefore: 0.75Ω o E h = ,435 = 5,479 kips Page 84

97 For this example, the controlling load case for overall building tsunami lateral load is LC2, with F dx = kip. 0.75Ω o E h = 5,479 kips < kips NG So the lateral force resisting system does not have ample capacity to resist the overall tsunami loads. Component Loads Drag Force on Components - Section Exterior Columns The exterior columns are assumed to have accumulated debris resulting in an increased tributary width of hydrodynamic load. Section will require that C d = 2.0 and the width dimension, b, be taken as the tributary width multiplied by the closure ratio value, C cx, given in Section Therefore b = 0.70x28 = 19.6 ft. The controlling load case will be LC2, when the inundated height of the element is h e = 12 ft and u max = 35.8 fps. The hydrodynamic drag is computed using Eqn as: F d = 1 2 ρ si tsu C d b(h e u 2 ) = ( )/1000 = 663 kips This load is applied to the column as an equivalent uniformly distributed lateral load of 663/12 = 55.3 kips/ft over the entire length of the column. The column must be designed for this load combined with gravity loads using the load combinations in Section Interior Columns Interior columns are 24 (2 ft) square R.C. columns. The controlling load case will be LC2, when the inundation height of the element is h e = 12 ft and u max = 35.8 fps. The hydrodynamic drag is computed using Eqn as: F d = 1 2 ρ si tsu C d b(h e u 2 ) Where C d = 2.0 for square columns (Table ) Therefore F d = 1 2 ρ si tsu C d b(h e u 2 ) = ( )/1000 = 67.7 kips This load is applied to the column as an equivalent uniformly distributed lateral load of 67.7/12 = 5.64 kips/ft over the height of the column. This load must be combined with gravity loads using the load combinations in Section and the column capacity. Debris Impact Loads - Section 6.11 The inundation depth at the site exceeds 3 feet, therefore exterior structural elements below the flow depth must be designed for debris impact loads per Section Alternative Simplified Debris Impact Static Load - Section In lieu of detailed debris impact analysis, the member can be designed for the maximum static load given by Eqn : F i = 330C o I tsu = = kips Since the building location is in an impact zone for shipping containers, ships, and barges, this entire force is used, and cannot be reduced by 50%. This load must be applied to the exterior Page 85

98 columns as a static lateral load at points critical for flexure and shear, in combination with gravity loads on the column. It is not combined with other tsunami loads and it need not be applied to interior columns. In the event that this load exceeds the column capacity, a detailed debris impact analysis can be performed. This detailed analysis may result in a smaller debris impact load. Page 86

99 Overall Building Forces Tsunami Design for Residential Building Section defines the following three Load Cases, which must be considered in the design. Because the calculation procedures for the overall building force for the three load cases were shown for the Hilo office building, only the calculations for the controlling load case (Load Case 2) will be shown for the residential building for simplicity. Load Case 2: Maximum Flow Velocity According to Figure 6.8-1, LC2 occurs when the inundation depth is 2/3h max = 2/3 x 55.0 = ft. Section , Eqn gives F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) Where all parameters are the same as for LC1 except: C d = 1.25 (Table based on B/h sx = 254/36.67 = 6.93) C cx(typ) = (A col+a wall )+1.5A beam = (( )+( ) ) = < 0.7 Bh sx Therefore C cx = 0.7 controls per Section Due to differing floor heights, the Ccx calculation was repeated for all floors. The Ccx value of the top inundated floor is also different due to the fact that the top inundated floor is only partially inundated by the tsunami. It was determined that Ccx = 0.7 controlled for all floors. For simplicity, only the Ccx calculation for the typical floor is shown. h = ft. u = u max = 35.8 fps So F dx = 1 2 ρ si tsu C d C cx B(hu 2 ) = ( )/1000 = kips This load is compared with the seismic base shear to determine if the lateral force resisting system has ample capacity to resist the overall tsunami loads. For the redesign of the lateral force resisting system, if needed, the force is distributed to each inundated floor and is applied to an ETABS model. Evaluation of Lateral Force Resisting System Because the structure has been designed for Seismic Design Category D, Section permits the use of 0.75 o E h to evaluate the lateral force resisting system (LFRS), where E h is the seismic base shear. From the seismic design of this structure, E h = 3,273 kips. Therefore; 0.75Ω o E h = ,273 = 7,364 kips For this example, the controlling load case for overall building tsunami lateral load is LC2, with F dx = kips. 0.75Ω o E h = 7,364 kips < kips NG So the lateral force resisting system does not have ample capacity to resist the overall tsunami loads. Page 87

100 Component Loads Drag Force on Components - Section Exterior Wall Exterior walls are assumed to have accumulated debris resulting in an increase tributary width of hydrodynamic load. Section requires that C d = 2.0 and the width dimension, b, be taken as the tributary width multiplied by the closure ratio value, C cx, given in Section However, C cx should be taken as 1.0, because the exterior shear wall has no openings over 28.Therefore b = 1.0x28 = 28.0 ft. The controlling load case will be LC2, when the inundation depth is h e = ft and u max = 35.8 fps. The hydrodynamic drag is computed using Eqn as: F d = 1 2 ρ si tsu C d b(h e u 2 ) = ( )/1000 = 2895 kips This load is applied to the wall as an equivalent uniformly distributed lateral load of 2895/(36.67*28) = 2.82 kips/ft over of a 1 ft section of wall. The wall must be designed for this load combined with gravity loads per Section Exterior Gravity Columns Interior columns are 20 (1.67 ft) square R.C. columns. The controlling load case will be LC2, when the inundation depth is is h e = ft and u max = 35.8 fps.. Section requires that C d = 2.0 and the width dimension, b, be taken as the tributary width multiplied by the closure ratio value, C cx, given in Section Therefore b = 0.7x28 = 19.6 ft. The hydrodynamic drag is computed using Eqn as: F d = 1 2 ρ si tsu C d b(h e u 2 ) Therefore F d = 1 2 ρ si tsu C d b(h e u 2 ) = ( )/1000 = 2027 kips This load is applied to the column as an equivalent uniformly distributed lateral load of 2027/36.67 = 55.3 kips/ft over the lower feet of the column. This load must be combined with gravity loads per Section and the column capacity verified. Tsunami Loads on Structural Walls, F w Section Since tsunami bores are anticipated at this location, the lateral load on the structural walls given by Eqn b must also be checked, and is given as: F d = 3 4 ρ si tsu C d b(h e u 2 ) Where C d = 2.0 for a wall per Table , and b = 28 and 10 for the elevator and stairwell walls respectively. Because the wall to inundation depth ratio must be three or more, the inundation depth is limited to 28 /3=9.33. Therefore, h/hmax = 9.33/55 = From Figure 6.8-1(a) and 6.8-1(b), the corresponding u/umax = Therefore, u = (0.65)(35.8) = 23.3 fps. Therefore: F d = ( )/1000 = 468 kips These loads are applied to the walls as a uniformly distributed load of 468/(9.33*28) = 1.79 kips/ft < 2.82 kips/ft over the lower 9.33 ft of a 1 ft section of wall. Therefore, bore loads will not control the hydrodynamic tsunami loading on the shear walls. Page 88

101 Debris Impact Loads - Section 6.11 The inundation depth exceeds 3 feet, therefore exterior structural elements below the flow depth must be Alternative Simplified Debris Impact Static Load - Section In lieu of detailed debris impact analysis, the member can be designed for the maximum static load given by Eqn : F i = 330C o I tsu = = kips Since the building location is in an impact zone for shipping containers, ships, and barges, this entire force is used, and cannot be reduced by 50%. This load must be applied to the exterior columns as a static lateral load at points critical for flexure and shear, in combination with gravity loads on the column. It is not combined with other tsunami loads and it need not be applied to interior columns. In the event that this load exceeds the column capacity, a detailed debris impact analysis can be performed. This detailed analysis may result in a smaller debris impact load. This equivalent static impact load of kips must also be applied to any structural walls on the perimeter of the building. This applies to the 28 ft wide elevator walls on both exterior sides of the building (GLs A and D) since impact must be considered during inflow and outflow conditions Page 89

102 Page 90

103 Appendix B ETABS Moment and Shear Diagrams SEISMIC LOADING DIAGRAMS SOIL D Hilo Soil D Elevator Shear Walls EW Seismic Loading (Moment Diagrams) Page 91

104 Hilo Soil D Elevator Shear Walls NS Seismic Loading (Moment Diagrams) Page 92

105 Oahu Soil D Elevator Shear Walls EW Seismic Loading (Moment Diagrams) Page 93

106 Oahu Soil D Elevator Shear Walls NS Seismic Loading (Moment Diagrams) Page 94

107 Monterey Soil D Elevator Shear Walls EW Seismic Loading (Moment Diagrams) Page 95

108 Monterey Soil D Elevator Shear Walls NS Seismic Loading (Moment Diagrams) Page 96

109 Hilo Soil D Stairwell Shear Walls EW Seismic Loading (Moment Diagrams) Page 97

110 Hilo Soil D Stairwell Shear Walls NS Seismic Loading (Moment Diagrams) Page 98

111 Oahu Soil D Stairwell Shear Walls EW Seismic Loading (Moment Diagrams) Page 99

112 Oahu Soil D Stairwell Shear Walls NS Seismic Loading (Moment Diagrams) Page 100

113 Monterey Soil D Stairwell Shear Walls EW Seismic Loading (Moment Diagrams) Page 101

114 Monterey Soil D Stairwell Shear Walls NS Seismic Loading (Moment Diagrams) Page 102

115 Hilo Soil D Elevator Shear Walls EW Seismic Loading (Shear Diagrams) Page 103

116 Hilo Soil D Elevator Shear Walls NS Seismic Loading (Shear Diagrams) Page 104

117 Oahu Soil D Elevator Shear Walls EW Seismic Loading (Shear Diagrams) Page 105

118 Oahu Soil D Elevator Shear Walls NS Seismic Loading (Shear Diagrams) Page 106

119 Monterey Soil D Elevator Shear Walls EW Seismic Loading (Shear Diagrams) Page 107

120 Monterey Soil D Elevator Shear Walls NS Seismic Loading (Shear Diagrams) Page 108

121 Hilo Soil D Stairwell Shear Walls EW Seismic Loading (Shear Diagrams) Page 109

122 Hilo Soil D Stairwell Shear Walls NS Seismic Loading (Shear Diagrams) Page 110

123 Oahu Soil D Stairwell Shear Walls EW Seismic Loading (Shear Diagrams) Page 111

124 Oahu Soil D Stairwell Shear Walls NS Seismic Loading (Shear Diagrams) Page 112

125 Monterey Soil D Stairwell Shear Walls EW Seismic Loading (Shear Diagrams) Page 113

126 Monterey Soil D Stairwell Shear Walls NS Seismic Loading (Shear Diagrams) Page 114

127 SEISMIC LOADING DIAGRAMS SOIL B Hilo Soil B Elevator Shear Walls EW Seismic Loading (Moment Diagrams) Page 115

128 Hilo Soil B Elevator Shear Walls NS Seismic Loading (Moment Diagrams) Page 116

129 Oahu Soil B Elevator Shear Walls EW Seismic Loading (Moment Diagrams) Page 117

130 Oahu Soil B Elevator Shear Walls NS Seismic Loading (Moment Diagrams) Page 118

131 Hilo Soil B Stairwell Shear Walls EW Seismic Loading (Moment Diagrams) Page 119

132 Hilo Soil B Stairwell Shear Walls NS Seismic Loading (Moment Diagrams) Page 120

133 Oahu Soil B Stairwell Shear Walls EW Seismic Loading (Moment Diagrams) Page 121

134 Oahu Soil B Stairwell Shear Walls NS Seismic Loading (Moment Diagrams) Page 122

135 Hilo Soil B Elevator Shear Walls EW Seismic Loading (Shear Diagrams) Page 123

136 Hilo Soil B Elevator Shear Walls NS Seismic Loading (Shear Diagrams) Page 124

137 Oahu Soil B Elevator Shear Walls EW Seismic Loading (Shear Diagrams) Page 125

138 Oahu Soil B Elevator Shear Walls NS Seismic Loading (Shear Diagrams) Page 126

139 Hilo Soil B Stairwell Shear Walls EW Seismic Loading (Shear Diagrams) Page 127

140 Hilo Soil B Stairwell Shear Walls NS Seismic Loading (Shear Diagrams) Page 128

141 Oahu Soil B Stairwell Shear Walls EW Seismic Loading (Shear Diagrams) Page 129

142 Oahu Soil B Stairwell Shear Walls NS Seismic Loading (Shear Diagrams) Page 130

143 SEISMIC LOADING DIAGRAMS SOIL D MOMENT FRAME Hilo EW Seismic Loading 24x28 Beams (Controlling Beam and Column Moment) Page 131

144 Hilo EW Seismic Loading 24x28 Beams (Controlling Beam Shear) Page 132

145 Hilo NS Seismic Loading 10 Beams (Controlling Beam Moment) Page 133

146 Hilo NS Seismic Loading 10 Beams (Controlling Column Moment) Page 134

147 Hilo NS Seismic Loading 10 Beams (Controlling Beam Shear) Page 135

148 Hilo NS Seismic Loading 10 Beams (Controlling Column Shear) Page 136

149 Oahu EW Seismic Loading 24x28 Beams (Controlling Beam and Column Moment) Page 137

150 Oahu EW Seismic Loading 24x24 Columns (Controlling Beam and Column Shear) Page 138

151 Oahu NS Seismic Loading 24x28 Beams (Controlling Beam Moment) Page 139

152 Oahu NS Seismic Loading 24x24 Columns (Controlling Column Moment) Page 140

153 Oahu NS Seismic Loading 24x28 Beams (Controlling Beam Shear) Page 141

154 Oahu NS Seismic Loading 24x24 Columns (Controlling Column Shear) Page 142

155 SEISMIC LOADING DIAGRAMS SOIL B MOMENT FRAME Hilo EW Seismic Loading 22x26 Beams (Controlling Beam and Column Moment) Page 143

156 Hilo EW Seismic Loading 22x26 Beams (Controlling Beam and Column Shear) Page 144

157 Hilo NS Seismic Loading 10 Beams (Controlling Beam Moment) Page 145