Port of New Orleans Design Resiliency Manual 2013

Transcription

1 Port of New Orleans Design Resiliency Manual 2013 Prepared by: MDM Design Group, Inc. 935 Gravier Street, Suite 686 New Orleans, LA In Conjunction With: 3500 N. Causeway Blvd., Suite 900 Metairie, LA Project No

2 Preface The information contained in this manual is provided for informational purposes only. It is intended to assist the user with the minimum standards set forth. PONO is not responsible for any errors or omissions. PONO makes no representations and disclaims all express, implied and statutory warranties of any kind as to accuracy, completeness or fitness for any particular purpose. PONO shall not have any liability in tort, contract, or otherwise to users and/or third parties.

3 TABLE OF CONTENTS ACRONYMS AND ABBREVIATIONS... ii SECTION ONE: INTRODUCTION Scope and Purpose Overview Objectives Limitations Acceptable Level of Risk Reference Publications SECTION TWO: MITIGATING FLOOD HAZARDS Flood Hazard Flood Mitigation Best Practices Protecting Buildings from Flood Hazard Events Elevating Structures Dry Floodproofing Require Use of Flood Damage-Resistant Materials Protecting the Building Envelope Protecting Utilities and Controls from Flood Hazard Events Electrical and Mechanical Systems Potable Water and Wastewater Systems Protecting Other Structures and Non-structures from Flood Hazard Events Sheds and Accessory Structures Fencing Signage Flood Mitigation Information Sources SECTION THREE: MITIGATING HIGH-WIND HAZARDS High-Wind Hazard High-Wind Mitigation Best Practices Protecting Buildings from High-Wind Events Strengthening New Buildings Strengthening Existing Buildings Strengthening the Structural Frame and Foundation Strengthening the Building Envelope Protecting Utilities and Equipment from High-Wind Events General Roof Top Equipment Electrical and Communications Equipment SECTION FOUR: REFERENCES Tables Table 1: Summary of currently adopted codes, standards, and regulations in New Orleans Table 2: Class Descriptions of Materials Table 3: Flood Mitigation Information Sources Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ i

4 TABLE OF CONTENTS Table 4: Saffir-Simpson Hurricane Wind Scale Figures Figure 1: Facilities map for Port of New Orleans (Source: PONO) Figure 2: FEMA s Design Framework to Achieve Successful Buildings (Source: FEMA 11) 1-4 Figure 3: Port of New Orleans Headquarters as shown on 1984 FIRM (Source: Louisiana State University Agricultural Center) Figure 4: Port of New Orleans Headquarters as shown on 2008 Preliminary Digital FIRM (Source: Louisiana State University Agricultural Center) Appendices Appendix A Repair/Replacement Guidelines Flowchart for Wind Damaged Sheds PONO Progressive Compliance Standards 2013 Appendix B Typical PONO Details Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ ii

5 Acronyms and Abbreviations BFE C&C MWRFS CMU DFE HMP FEMA FIRM DFIRM OSB PONO SFHA NFIP Base Flood Elevation Components and Cladding Main Wind Force Resisting System Concrete masonry unit Design Flood Elevation Hazard Mitigation Plan Federal Emergency Management Agency Flood Insurance Rate Map Digital Flood Insurance Rate Map Oriented Strand Board Port of New Orleans Special Flood Hazard Area National Flood Insurance Program Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ iii

6 Introduction 1.1 SCOPE AND PURPOSE SECTION ONE: INTRODUCTION The Port of New Orleans (PONO) Hazard Mitigation Plan (HMP) (2009) identifies the need for port-wide design criteria and guidance for incorporating mitigation strategies into new construction projects or for hazard mitigation of existing structures. This Design Guidebook (Guidebook), prepared for the PONO, describes applicable codes, standards, and guidance regarding best practices for hazard-resistant design at their port facilities. The guidance in this Guidebook applies to both new construction as well as the rehabilitation, modification, or retrofit of existing facilities. This Guidebook is intended to be a starting point for designers, architects, engineers, and contractors who are familiar with the design and construction of PONO facilities. The PONO HMP acknowledges the need for multi-hazard mitigation to reduce property damage and lessen the impact of natural and man made hazards. It describes 16 natural and man-made hazards specific to New Orleans, and outlines historical occurrences, frequency, threat to people, and property damage for each of these hazards specific to the PONO. The risk assessment in the PONO HMP identifies the following hazards as the most significant for their facilities: flood and wind due to hurricanes (Categories 3, 4, and 5), allision, and hazardous materials incidents. This Guidebook will focus on mitigation strategies to lessen the impact of flooding and high wind due to hurricanes (Categories 3, 4, and 5). 1.2 OVERVIEW The majority of PONO facilities are located in Orleans Parish, LA, but facilities are also located in Jefferson and St. Bernard Parishes. Existing facilities, shown in Figure 1, include 20 million square feet of cargo handling area, over 3.1 million square feet of covered storage area, 1.7 million square feet of cruise ship and parking facilities, and one headquarters building. The PONO is one of the largest ports in the United States by cargo tonnage, and is a significant contributor to the local and regional economy. Multi-hazard mitigation at the PONO is essential to protect life, minimize damage to the port s facilities and assets, and allow PONO to recover and maintain continual operations following natural hazard events. The PONO returned to partial operability in a short period of time following flood and wind damage resulting from Hurricane Katrina in 2005, but did not fully reopen all facilities for 4 months. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 1-1

7 Introduction 1.3 OBJECTIVES Figure 1: Facilities map for Port of New Orleans (Source: PONO) As stated in the PONO HMP (page 113), the mitigation goals established for the PONO are: 1. Protect life at the PONO. 2. Minimize damage from hazards to critical PONO infrastructure, those facilities and assets so vital that their destruction or incapacitation will have a debilitating effect on the security, economy, safety, health, and welfare of the public. For the purposes of this HMP, critical infrastructure may be built (structural, energy, water, transportation and communication systems), natural (surface water resources such as the Mississippi River), or virtual (cyber, electronic data, and information systems). 3. Enhance business resiliency, the capability to mitigate against the hazards identified in this HMP that threaten the PONO, and expeditiously recover and reconstitute critical services with minimum delay and damage to public safety and health, the economy, and security. 4. Provide for continuity of PONO services to the greatest extent practical in the face of these hazards Limitations It is important to understand that a building is typically not intended to resist all levels of flooding and high-wind events only to those design levels and criteria specified. For events such as a major hurricane or a tornado, which have levels above those specified in building codes Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 1-2

8 Introduction buildings are typically not intended to provide life-safety protection per the building code. While constructing and retrofitting PONO buildings and structures to increase their resiliency and thereby allow continuity of operations after an event, it would be economically infeasible to transform the structures such that they would not be damaged from any event, no matter how extreme Acceptable Level of Risk As with any facility, building, or structure, the acceptable level of risk for the PONO must be determined. Due to the importance and criticality of the PONO, the acceptable level of risk should be higher than prevailing design levels and typical construction. The Federal Emergency Management Agency (FEMA) defines a successful disaster-resistant structure as one that is capable of resisting damage from distinct events (such as hurricanes) and ongoing processes (such as subsidence) over a period of decades. This does not mean that a building will remain undamaged over its intended lifetime, rather that damage will be limited. According to FEMA s Coastal Construction Manual (FEMA P-55, 2011, page 1-3), the following should be true in order for a building to be considered successful after a design-level flood and/or wind event: The building foundation is intact and functional The envelope (lowest floor, walls, openings, and roof) is structurally sound and capable of minimizing penetration of wind, rain, and debris. The building is accessible and habitable The lowest floor elevation is high enough to prevent floodwaters from entering the building envelope The utility connections (e.g., electricity, water, sewer, natural gas to the building) remain intact or can be easily restored Any damage to enclosures below the lowest floor does not result in damage to the foundation, utility connections, or elevated portions of the building or nearby structures FEMA follows a design framework centered on the premise that anticipated loads must be transferred through the building in a continuous path to the supporting soils. A number of issues and constraints must be addressed to realize this design framework (Figure 2). Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 1-3

9 Introduction Figure 2: FEMA s design framework to achieve successful buildings (Source: FEMA 2011) The framework shown in Figure 2 for designing a successful hazard-resistant building is used as the basis for the best practices hazard-resistant design guidance offered in this Guidebook. For more information on FEMA s approach to successful buildings and best practices, see Section 1.3 of FEMA P-55, Coastal Construction Manual (FEMA 2011). 1.4 REFERENCE PUBLICATIONS This document provides information on specific sections of available publications, including codes, standards, regulations, and best practices guidance. Building codes and referenced design and construction standards set the minimum requirements for structural and non-structural design and apply primarily to new construction, but may also apply to modifications of existing buildings when required by codes or local regulations. A summary of the codes, standards, and Federal regulations application to PONO are shown in Table 1. As a best practice, the PONO should always design buildings based on the latest available codes and standards. At the time of this publication, the latest available model codes are the 2012 International Codes published by the International Code Council (ICC). At the time of this publication, Louisiana has adopted the 2009 editions of the following model codes from the International Code Series published by the International Code Council (ICC): International Building Code (IBC) (ICC 2009a) International Residential Code (ICC 2009b) International Existing Building Code (ICC 2009c) International Mechanical Code (ICC 2009d) International Fuel Gas Code (ICC 2009e) Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 1-4

10 Introduction International Energy Conservation Code (ICC 2009f) International Existing Building Code (ICC 2009g). In addition, New Orleans has adopted the International Fire Code (ICC 2009h). The guidance provided in this Guidebook for designing and constructing structures at the PONO are based primarily on the requirements specified in the IBC. The IBC incorporates numerous standards by reference rather than by inclusion of additional text within the code. Applicable flood and wind standards referenced by the 2009 IBC are: ASCE 7-05, Minimum Design Loads for Buildings and Other Structures (ASCE 2005a) ASCE 24-05, Flood Resistant Design and Construction (ASCE 2005b) New Orleans participates in the National Flood Insurance Program (NFIP). Therefore, locally adopted floodplain management regulations in New Orleans must meet or exceed the minimum regulatory requirements set forth in Title 44 of the Code of Federal Regulations (CFR) Section 60.3 (44 CFR 60.3). New Orleans floodplain regulations are currently outlined in the City of New Orleans, Louisiana, Code of Ordinances Ordinance No , Article II, Flood Damage Prevention. Best practices guidance publications describe design and practices that exceed the minimum requirements set forth in building codes; design and construction standards; and Federal, State, and local regulations. A majority of the guidance on best practices referenced in this Guidebook is published by FEMA, a A complete list of FEMA Building Science guidance can be found online at dingscience/publications.shtm. nationally recognized government authority on mitigating natural hazards. FEMA s guidance on best practices is based on several decades of post-disaster investigations that evaluate the success and failure of buildings in response to natural and man-made hazard events. Table 1: Summary of currently adopted codes, standards, and regulations in New Orleans Building Codes Adopted by State of Louisiana Agencies (Recommended for formal adoption by PONO) Adopted by City of New Orleans Design and Construction Standards Through reference in the 2009 International Building Code 2009 International Building Code 2009 International Residential Code 2009 International Existing Building Code 2009 International Mechanical Code 2009 International Fuel Gas Code 2009 International Energy Conservation Code 2009 International Existing Building Code 2009 International Fire Code & All of the above ASCE 7-05, Minimum Design Loads for Buildings and Other Structures ASCE 24-05, Flood Resistant Design and Construction Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 1-5

11 Introduction Floodplain Management Regulations NFIP Communities Minimum Requirements applicable to PONO Enacted by New Orleans (Recommended for formal adoption) Title 44 of the Code of Federal Regulations Section 60.3 (44 CFR 60.3) Code of Ordinances Ordinance No , Article II, Flood Damage Prevention. 20of%20New%20Orleans,%20Louisiana,%20Ordinance%20No.% pdf Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 1-6

12 Mitigating Flood Hazards 2.1 FLOOD HAZARD SECTION TWO: MITIGATING FLOOD HAZARDS New Orleans is uniquely situated primarily below sea level, and is at risk of flooding from both coastal and riverine sources. The PONO HMP identifies flood risks from high Mississippi River conditions, severe storms causing tidal surges, stormwater flooding, groundwater flooding, levee or floodwall failure, and levee failure from low Mississippi River conditions. Nearly all PONO facilities are located on the unprotected side of the Mississippi River flood protection system, between the flood protection system and the Mississippi River, at an elevation of approximately 20+ feet above sea level. Some PONO facilities are at an elevation of 10+ feet above sea level and are located between the Lake Pontchartrain hurricane flood protection system and the Inner Harbor Navigation Canal, Gulf Intracoastal Waterway, or the Mississippi River Gulf Outlet. The most damaging flooding at PONO facilities has resulted from hurricanes. In August of 2005, Hurricane Katrina struck Louisiana and the Gulf Coast as the costliest natural disaster in the history of the United States. Hurricane Katrina was soon followed by Hurricane Rita in September of The combined rainwater, storm surge, and levee failures from these two hurricanes caused $250 million in damage at the PONO (this cost includes wind damage). The most significant damage at the PONO from the 2005 hurricane season occurred as a result of storm surge (overtopping and levee failure) and wind, vessel allisions, roof and damage to containers from wind, and flooding due to storm surge. Although the current Effective Flood Insurance Rate Map (FIRM) dated March 1, 1984 indicates that PONO riverside property is in an area of minimal flood hazard (Zone B), the latest available preliminary digital FIRM released in 2008 (set to be adopted in 2012) shows an expansion of the Zone A special flood hazard area (SFHA) along the Mississippi River in the vicinity of PONO property. PONO properties on the IHNC inside and outside the floodwalls are currently located in Zone A with an elevation of 12 feet, the new map will also be Zone A but with a revised elevation of 6 feet. For FEMA warns that FIRMs do not account for future effects of sea level rise and long-term erosion. All mapped flood hazard zones (V, A, and X) in areas subject to sea level rise and/or long-term erosion likely underestimate the extent and magnitude of actual flood hazards that a coastal building will experience over its lifetime (FEMA 2011). example, as shown in Figures 3 and 4, the PONO headquarters building is located in Zone B on the Effective FIRM, but is located in Zone AE on the preliminary digital FIRM. The base flood elevation (BFE) on the preliminary digital FIRM for the location is 18 feet above sea level, and the ground elevation is 15.4 feet. Therefore, according to the preliminary digital FIRM, this building is at risk of flooding from the 1-percent-annual-chance flood event (commonly called the 100-year flood event). All PONO property on the flood-side of the federally certified riskreduction system, i.e. floodwalls and levees, are at risk of flooding. It is important to refer to the preliminary digital FIRM for each building site when determining flood risk and BFE. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-1

13 Mitigating Flood Hazards Figure 3: Port of New Orleans Headquarters as shown on 1984 FIRM (Source: Louisiana State University Agricultural Center) Figure 4: Port of New Orleans Headquarters as shown on 2008 preliminary digital FIRM (Source: Louisiana State University Agricultural Center) Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-2

14 Mitigating Flood Hazards Figure 5: Port of New Orleans IHNC properties on 2008 preliminary digital FIRM (Source: Louisiana State University Agricultural Center) LEGEND FOR FIRM Special Flood Hazard Areas Inundated By 100-Year Flood ZONE A ZONE AE ZONE AH ZONE AO ZONE A99 ZONE V ZONE VE No base flood elevations determined. Base flood elevations determined Flood depths of 1 to 3 feet (usually areas of ponding); base flood elevations determined Flood depths of 1 to 3 feet (usually sheet flow on sloping terrain); average depths determined. For areas of alluvial fan flooding; velocities also determined To be protected from 100-year flood by Federal flood protection system under construction; no base flood elevations determined Coastal flood with velocity hazard (wave action); no base flood elevations determined Coastal flood with velocity hazard (wave action); no base flood elevations determined Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-3

15 Mitigating Flood Hazards 2.2 FLOOD MITIGATION BEST PRACTICES Floodwaters can damage or destroy structures through flotation, collapse, and lateral movement resulting from hydrodynamic and hydrostatic loads. These loads include: Standing or slow-moving water Storm surge Wave runup Outflow of floodwaters Strong currents Flood-borne debris Erosion and localized scour In addition to structural damage, floodwaters can damage building materials, interior finishes, and building contents. The flood mitigation best practices outlined in this Guidebook are applicable to all flood forces and sources of flooding at the PONO. Because a majority of PONO riverfront facilities and IH-NC/GIWW facilities are located in or near Zone A, the flood mitigation guidance provided is for buildings located in Zone A Protecting Buildings from Flood Hazard Events The IBC, through reference to ASCE 7, requires that buildings be designed, constructed, connected, and anchored to resist flotation, collapse, and permanent lateral displacement due to the action of flood loads associated with the design flood. The design flood at the PONO is the 1- percent-annual-chance flood (also known as the 100-year flood). One way to increase the flood resistance of the PONO is to select a more conservative design flood, such as the 0.2-percentannual-chance flood (also known as the 500-year flood). This allows for more conservative design regarding flood loads on the structure, and also increases the height to which buildings are elevated and/or floodproofed. Preliminary design should be prepared, costed, and a cost-benefit analysis performed to determine the reasonableness of the higher level of protection. The IBC and its referenced standards use risk or occupancy category to classify structures. Category I represents structures with a low hazard to human life in the event of failure, and Category IV represents critical and essential facilities. Although most of the facilities at the PONO can be categorized as Category II or III (see Table 1-1 of ASCE 7-10), designing the structure for a higher occupancy or risk category allows for a more conservative elevation and more conservative flood loads, resulting in a stronger design that is more resistant to flood events. Proper siting, elevation, and floodproofing are the main ways to resist or avoid flood damage to structures and their foundations. However, PONO facilities have limited siting options due to the requirement that port facilities be located adjacent to waterways. Therefore, this Guidebook focuses on elevation and dry floodproofing as the primary mitigation methods. Additionally, the Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-4

16 Mitigating Flood Hazards following discussion describes the required use of flood-resistant materials and best practices related to protecting the building envelope Elevating Structures A properly designed foundation connected to a continuous load path is critical to a successfully flood-resistant building when the flood hazard cannot be avoided through siting. Foundations must support gravity loads, and resist uplift (flotation) and lateral loads. Foundations in coastal areas must also resist high winds and corrosion. Foundation designs should explicitly account for all design loads and conditions. In addition to properly accounting for flood loads in the design of the foundation, the foundation should be elevated to a specified design flood elevation. Elevation is preferred over floodproofing for new construction. There are several acceptable ways to elevate a building in Zone A. FEMA s recommendations are summarized below: Slab-on-grade foundation on structural fill: If velocities are high or debris load is anticipated, open foundations are recommended in lieu of elevating on fill (FEMA 2011). Slab-on-grade foundations are not appropriate for many of the PONO facilities, especially those closer to the water where flood-borne debris is a concern. If structural fill is used, the fill must be designed to minimize adverse impacts, such as increasing flood elevations on adjacent properties, increasing erosive velocities, and causing local drainage problems. A geotechnical engineer should examine the underlying soils to determine if the bearing capacity of the soil is sufficient. The community may require that buildings elevated on fill are reasonably safe from flooding. See ASCE 24 Section 2.4 for fill requirements and Section 2.5 for slab-on-grade-footing requirements. Solid foundation walls/closed foundations: If velocities are high or debris load is anticipated, open foundations are recommended in lieu of elevating on solid walls (FEMA 2011). Stem wall foundations are the most stable closed foundation because the foundation is backfilled and hydrostatic pressures are minimized. Continuous perimeter walls that enclose an open area or crawlspace must have flood openings that are designed to equalize interior and exterior water levels. See ASCE 24 Section 2.6 and 4.6 for requirements related to enclosures below the DFE. Open foundations: Open foundations on piles, piers, columns, or posts are recommended in Zone A if riverine velocities are high or debris load is anticipated. See ASCE 24 Section 4.4 for requirements related to open foundations. Open foundations minimize changes to the floodplain and local drainage patterns, and the use of the area under the building is restricted to parking and storage. The design may need to take into account the increased exposure to wind, uplift, and breaking waves Dry Floodproofing If a building cannot be elevated, dry floodproofing can be used to protect the building from flooding. Dry floodproofing may be a more practical solution for retrofitting an existing Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-5

17 Mitigating Flood Hazards building. Dry floodproofing lowers the potential for flood damage by reducing the frequency of floodwaters that enter the structure. Dry floodproofing measures include: Installing watertight shields for doors and windows and using membranes and sealants to reduce seepage of floodwaters (walls must be design checked to resist the additional water loads) Reinforcing walls to withstand floodwater pressures and impact forces generated by floating debris Installing drainage collection systems, sump pumps, and check valves to control water levels and prevent backflow of floodwaters Require Use of Flood Damage-Resistant Materials Guidance for flood damage resistant materials can be found in FEMA Technical Bulletin 2, Flood Damage-Resistant Materials Requirements (FEMA 2008a). Building materials are classified according to their ability to resist flood damage. Only class 4 and 5 materials are acceptable for use below the design flood elevation (DFE). When practical, DFE should be at or above the base flood elevation (BFE). In accordance with the NFIP, all materials below the DFE must be durable, resistant to flood forces, and retardant to deterioration caused by repeated exposure to floodwater. This requirement applies to structural materials, the building envelope, and interior finishes. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-6

18 Mitigating Flood Hazards Table 2: Class Descriptions of Materials Notes: 1. Floodwater is assumed to be considered black water; black water contains pollutants such as sewage, chemicals, heavy metals, or other toxic substances that are potentially hazardous to humans. 2. Moving water is defined as water moving at low velocities of 5 feet per second (fps) or less. Water moving at velocities greater than 5 fps may cause structural damage to building materials. 3. Some materials can be successfully cleaned of most of the pollutants typically found in floodwater. However, some individual pollutants such as heating oil can be extremely difficult to remove from uncoated concrete. These materials are flood damage-resistant except when exposed to individual pollutants that cannot be successfully cleaned. 4. Clean water includes potable water as well as gray water; gray water is wastewater collected from normal uses (laundry, bathing, food preparation, etc.). 5. For Types, Uses, and Classification of Materials see Table 2 at MODIFIED FROM: USACE 1995 Flood Proofing Regulations Protecting the Building Envelope (Source: FEMA 2008) Protecting the building envelope is critical to protecting interior finishes and contents. Protecting contents at PONO storage facilities is especially important for the local and regional economy to return to normal operations following a flood event. In addition to using flood damage-resistant materials, the building envelope should be designed to avoid wind-driven rain. Although developed for residential construction, the principles in FEMA P-499, Home Builders Guide to Coastal Construction (FEMA 2010a) Fact Sheets 1.9 (Moisture Barrier Systems), 6.1 (Window and Door Installation), and 7.5 (Minimizing Water Intrusion through Roof Vents in High-Wind Regions) would apply to PONO s facilities in designing building envelopes to seal the building from rainwater penetration and seepage. It is critical that the design and installation of new Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-7

19 Mitigating Flood Hazards windows and doors, including the sealing and glazing, be tested for water tightness prior to acceptance Protecting Utilities and Controls from Flood Hazard Events Continuity of operations after a flood event requires the survival and functionality of critical utilities and equipment at the facility. Flooding can damage utility systems, potable water systems, and wastewater systems. The failure of such systems can significantly impair the operation of the facility and, in the case of failure of the wastewater system, can pose a serious hazard to public health. In addition, floods can detach improperly anchored equipment, and allow water to enter the facility where equipment was displaced Electrical and mechanical systems Electrical and mechanical utilities can best be protected from flooding by elevating them to a height above the DFE. Designers should pay particular attention to under-floor utilities and ductwork to ensure that they are properly elevated. Electrical and other conduits below the DFE should be properly located and anchored to resist the effects of flooding. Utilities and equipment located outside of the building must also be elevated on platforms that are attached to the primary structure these platforms should be designed to resist all flood loads. Backflow preventers should be installed on water and sewer. Permanent generators with onsite fuel sources, such as propane or diesel tanks, should be used to provide emergency power. Portable generators require human intervention and require that the generator be in the right place at the right time. After Hurricane Katrina, FEMA observed a number of generator failures at critical facilities because the generators relied on offsite fuel sources, such as city natural gas pipes, which were cut off due to damage. ASCE 24 specifies that aboveground storage tanks be elevated, and be designed and anchored to resist at least 1.5 times the potential buoyant and other flood forces under design flood conditions, assuming an empty tank. Critical structures with generators should have automatic transfer switches Potable water and wastewater systems Potable water systems and wastewater collection system are required to resist flood damage, especially damage associated with infiltration of floodwaters and discharge of effluent. Failure of these systems poses a public health hazard. Onsite water supplies should be located on land elevated above the surrounding landscape to allow contaminated surface water and runoff to drain away from the site. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-8

20 Mitigating Flood Hazards Sewer collection lines should be located and designed to avoid filtration and backup due to rising floodwaters. Secondary backup devices should be used as redundant measure of protection. Additional information can be found in FEMA 543, Design Guide for Improving Critical Facility Safety from Flooding and High Winds (2007) Protecting Other Structures and Non-structures from Flood Hazard Events In addition to buildings, the PONO should pay attention to accessory and attached structures, as well as fencing, signage, and other items should be considered. Elements that are not directly attached to buildings should still be considered when determining how to mitigate damage from flood events. If torn loose, these items can become large flood-borne debris that can be and impose forces on other buildings and port infrastructure Sheds and Accessory Structures Accessory structures are often over-looked components. These structures are typically sheds, temporary buildings, walkways, canopies, or other structures that may be used for secondary functions. The vulnerabilities of these structures should be considered regardless of whether or not they protect critical equipment or functions. When accessory structures that are attached to buildings fail during a flood event, internal building components are often exposed; such failures can lead to flooding of the entire building. Accessory structures must be properly elevated and anchored to resist flood forces, even in those cases where mitigation is not intended to maintain full functionality of the structure. The NFIP requirement for use of flood damage-resistant materials applies to accessory buildings as well as main buildings. Although written for manufactured homes, the principles in FEMA P- 85, Protecting Manufactured Homes from Floods and Other Hazards (FEMA 2009a), apply to smaller accessory structures and portable units Fencing Fences have the potential to become flood-borne debris and the potential to trap flood-borne debris. Fences should be designed with openings to allow for the automatic entry and exit of floodwaters to equalize hydrostatic flood forces. Fences should also be designed using flood damage-resistant materials below the DFE. Fences that are perpendicular to the shoreline are more likely to become damaged. Non-essential fences can be designed to break apart, although these fences would then become flood-borne debris. For guidance on typical fence and gates details, refer to Appendix B Typical PONO Details Signage Signs on posts have the potential to become flood-borne debris if not properly embedded in the soil. Sign posts should be properly embedded in the soil and account for scour and erosion. 2.3 FLOOD MITIGATION INFORMATION SOURCES Sources of design requirements and best practices guidance are summarized in Table 3. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-9

21 Mitigating Flood Hazards Mitigation Table 3: Flood Mitigation Information Sources Source General flood design requirements ASCE 24 Flood load calculations ASCE 7 Chapter 5 Foundation design ASCE 24 Section 1.5 FEMA P-55 Chapter 10 FEMA P-550 FEMA 543 Section Elevation ASCE 24 Section 2.3 Slab-on-grade and slab-on-fill ASCE 24 Section 2.4 ASCE 24 Section 2.5 Enclosures below the DFE ASCE 24 Section 2.6 ASCE 24 Section 4.6 Open foundations ASCE 24 Section 4.4 Dry floodproofing FEMA P-259 Chapter 5D ASCE 24 Section 6.2 FEMA 543 Section Flood damage-resistant materials FEMA Technical Bulletin 2 Protecting the building envelope FEMA P-499 Fact Sheet 1.9 FEMA P-499 Fact Sheet 6.1 FEMA P-499 Fact Sheet 7.5 Utilities ASCE 24 Chapter 7 FEMA 543 Section Accessory Structures FEMA P-85 Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 2-10

22 Mitigating High-Wind Hazards 3.1 HIGH-WIND HAZARD SECTION THREE: MITIGATING HIGH-WIND HAZARDS The PONO HMP identified wind risks from local thunderstorms, tropical storms, hurricanes, and tornadoes. Tropical storms, hurricanes, and other coastal storms that affect the New Orleans, LA, area occur in varying strengths and intensities. Tropical storms have wind speeds of between 39 and 74 mph (1-minute sustained), while hurricanes have wind speeds of greater than 74 mph (1-minute sustained). Hurricanes are divided into five classes according to the Saffir-Simpson Hurricane Wind Scale (SSHWS), which uses 1- minute sustained wind speed at a height of 33 feet over open water as the sole parameter to categorize storm damage potential (see Table 4). Table 4: Saffir-Simpson Hurricane Wind Scale (Source: FEMA 2011) Hurricane Katrina struck the New Orleans area as a Category 3 hurricane in August 2005, significantly damaging the PONO facilities. FEMA 549, Hurricane Katrina in the Gulf Coast, estimated the wind speeds from Katrina in New Orleans to be approximately 105 mph (3-second gust). While the flooding from Katrina was a larger factor in the overall damage, the high-winds also caused damage throughout the city. The hurricane caused significant damage to the PONO, and while the PONO was operational within two weeks, portions of the port were closed for 4 months following Katrina. 3.2 HIGH-WIND MITIGATION BEST PRACTICES High winds can damage structures through both wind pressures, applied directly on the structure, and by creating wind-borne debris that can strike the structure. The debris can originate from the Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-1

23 Mitigating High-Wind Hazards structure itself or from surrounding sources. The effects of high winds on a building depend on many factors, including: Wind speed and duration of winds Height of the building above the ground Exposure or shielding of the building (by topography, vegetation, or other buildings) relative to the wind direction Strength of the structural frame, connections, and envelope (walls and roof) Shape of the building and building components Number, size, location, and strength of openings in the building (e.g., windows, doors, vents) Presence and strength of shutters or opening protection Type, quantity, and velocity of wind-borne debris Even when wind speeds do not exceed design levels, buildings can suffer extensive wind damage when they are improperly designed and constructed. Proper design and construction of structures, particularly those close to open water, demand that every factor be assessed and addressed carefully. Buildings are generally not intended to resist all levels of high-wind events; buildings constructed in compliance with building codes are typically intended to provide life-safety protection for the intended loads. When considering events such as major hurricanes (Categories 3, 4, and 5) and tornadoes, it is generally more economical for facility owners to construct a safe room or storm shelter to provide life-safety protection to occupants. wind. These facilities are designed to higher levels of While a major hurricane may warrant a mandatory evacuation for a region, the criticality of the facility may necessitate that some staff remain onsite through the storm to provide continuity of operations afterwards. Provision of a safe room may be an economically feasible option to provide protection to occupants. The level of protection afforded by a safe room ICC 500, Standard for the Design and Construction of Storm Shelters (2008), provides design requirements for storm shelters. FEMA P-361, Design and Construction Guidance for Community Safe Rooms (2008b), provides design guidance for safe rooms. could also be provided for components of the PONO that are critical to continuity of operations, such as emergency generators and other equipment. The following sections provide design considerations for high-wind events. The information is primarily taken from Section 3.3 of FEMA 543, Design Guide for Improving Critical Facility Safety from Flooding and High Winds (2007). For additional considerations and best practices, see Section 3.4 of FEMA 543. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-2

24 Mitigating High-Wind Hazards Protecting Buildings from High-Wind Events Strengthening New Buildings Required wind loads are calculated by reference to the design standard ASCE 7, Minimum Design Loads for Buildings and Other Structures. The most current version, ASCE 7-10, uses a slightly different approach to developing the wind loads for buildings and other structures than the older version, ASCE 7-05, which IBC 2009 adheres to. IBC 2012, not yet adopted by the State of Louisiana, adheres to ASCE In ASCE 7-05, the previous edition of ASCE 7, the minimum design wind speed at the PONO would be 130 mph (3-second gust) for guidance. ASCE 7-05 would then use the Importance Factor in the equation to develop wind pressure. For example, an important building might be designed with an Importance Factor of 1.15, resulting in a 15 percent increase in design wind pressures. In ASCE 7-10, however, different wind maps (based on different mean recurrence intervals) are provided for structures based on occupancy category. According to ASCE 7-10 and using a 3- second gust wind speed for structures at the PONO: Occupancy category I structures at the PONO should have a minimum design wind speed of 130 mph or the latest IBC adopted by the PONO. This category covers transit sheds and buildings that represent a low hazard to human life in the event of failure, among others. Occupancy category II should not be used at the PONO sheds. Occupancy category III structures have a design wind speed of 130 mph or the latest IBC adopted by the PONO. This category covers buildings and other structures where more than 300 people congregate in one area. Occupancy category IV structures should have a minimum design wind speed of 130 mph or the latest IBC adopted by the PONO. This category includes those buildings that the PONO considers vital and essential for PONO operations and where the PONO desires maximum resiliency. New building construction can be designed to resist or minimize damage from high-wind events. Examples of conservative measures that can be taken to go beyond code requirements include: Designing structures for higher occupancy category levels to provide greater resistance to high-wind events Using an exposure category that is more conservative (ASCE 7-05 categories). Surface roughness categories: Exposure D shall apply where the ground service roughness, as defined by surface roughness D, prevails in the up-wind direction for a distance greater than 5,000 ft or 20 times the building height, whichever is greater. Exposure B shall apply where the ground surface roughness condition as defined by surface roughness B, prevails in the up-wind direction for a distance of at least 2,600 ft or 20 times the building Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-3

25 Mitigating High-Wind Hazards height, whichever is greater. Exposure C shall apply for all cases where Exposures D or B do not apply. Designing buildings that are partially enclosed, even when the criteria for an enclosed structure is met. It should be noted that when the PONO ever decides to adopt IBC 2012, the corresponding ASCE 7-10 allows exposure D only Strengthening Existing Buildings While new buildings can be properly designed and constructed to meet the desired performance criteria, existing buildings may represent a more difficult challenge. In order to retrofit an existing building, each individual building or structure must be evaluated. A standard set of retrofits should not be applied to all buildings, since each existing building may have its own unique vulnerabilities. For example, if an existing building has a deteriorated roof structure, providing shutters on the openings of the building is not likely to increase the protection to the building at all. If the roof of the building fails, the shutters will not make much of a difference in the performance of the building, and the money spent to retrofit that item will have been wasted. Therefore in order to determine how a building may be effectively retrofitted to resist high-wind events, an evaluation should be performed. Chapter 3 of FEMA P-804, Wind Retrofit Guide for Residential Buildings (2010b), discusses the evaluation process. While FEMA P-804 was written primarily for wood-frame, residential structures, the techniques and processes described in the publication may be adapted and applied to other types of structures. Appendix B of FEMA P-804 also provides further evaluation guidance, including key information to collect for an evaluation report Strengthening the Structural Frame and Foundation The structure of a building, also known as the main wind force resisting system (MWFRS), is the skeleton that provides structural support. The structure includes the structural frame and foundation. It is important for any building subjected to high winds to have a continuous load path present. A continuous load path refers to the structural condition required to resist loads acting on a building. A load path can be thought of as a chain running through the building. A building may contain hundreds of continuous load paths. The continuous load path starts at the point or surface where loads are applied, moves through the building, continues through the foundation, and terminates where the loads are transferred to the soils that support the building. Because all applied loads must be transferred to the foundation, the load path must connect to the foundation. To be effective, each link in the load path chain must be strong enough to transfer loads without breaking. The Port of New Orleans owns transit sheds and other structures that date back to the Port s inception. These sheds and structures were not designed for today s wind speeds, and therefore a structural analysis is required before any improvements are implemented. A feasibility analysis will then be developed in order to decide the feasibility of the structural upgrades. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-4

26 Mitigating High-Wind Hazards Section of FEMA 543, Design Guide for Improving Critical Facility Safety from Flooding and High Winds, provides the following recommendations to improve the performance of structural systems: Pre-engineered metal building: Special steps should be taken to ensure the structure has more redundancy than is typically the case with pre-engineered buildings. Steps should be taken to ensure the structure is not vulnerable to progressive collapse in the event a primary bent (steel moment frame) is compromised or bracing components fail. Exterior load-bearing walls of masonry or precast concrete: Should be designed to have sufficient strength to resist external and internal loading when analyzed as components and cladding (C&C, e.g., the building envelope). Concrete masonry unit (CMU) walls should have vertical and horizontal reinforcing and be intentionally grouted to resist wind loads. The connections of precast concrete wall panels should be designed to have sufficient strength to resist wind loads. Roof decks: Use of concrete, steel, is recommended. Steel roof decks: Specify a screw attachment rather than puddle welds or powder-driven pins. Screws are more reliable and much less susceptible to workmanship problems. Precast concrete decks: Deck connections should be designed to resist the design uplift loads because the deck dead load itself is often insufficient to resist the uplift. Precast Tee decks: Reinforcing should be designed to accommodate the uplift loads from rising in water levels and waves in addition to the gravity loads. Otherwise, large uplift forces can cause member failure due to the Tee s own pre-stress forces after the uplift load exceeds the dead load of the Tee. Buildings with mechanically attached single-ply or modified bitumen membranes: Designers should refer to the decking recommendations presented in the Wind Design Guide for Mechanically Attached Flexible Membrane Roofs, B1049 (National Research Council of Canada, 2005) Strengthening the Building Envelope While the structural frame and foundation provide much of the load resistance for a building, the building envelope, also known as Components and Cladding (C&C), is also a determining component in the performance of a building during a high-wind event. Breaches to the building envelope during a high-wind event can lead to wind-driven rain penetration, peeling and progressive damage to the envelope, and damage to other portions of the structure that become unprotected. Additionally, breaches in the building envelope, in combination with wind interaction with a building, can cause either an increase in the pressure within a building (i.e., positive internal pressure), or it can cause a decrease in the pressure (i.e., negative internal pressure). In either situation the loads imparted on the structure are significantly altered, and in some cases this can lead to structural failure. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-5

27 Mitigating High-Wind Hazards The building envelope acts as the skin of a building and covers most, if not all, areas exposed to wind; therefore it is an important component in the continuous load path. All elements of the envelope should be capable of transferring the loads applied in a high-wind event to the structure, where they can be transferred to the foundation and into the ground. FEMA 543, Section 3.3.3, provides recommendations for design considerations of building envelopes, including the following: Exterior doors (primary and secondary egress doors, sectional, and rolling doors): The IBC requires that the door assembly (i.e., door, hardware, frame, and frame attachment to the wall) be of sufficient strength to resist the positive and negative design wind pressure. Design professionals should require that doors comply with wind load testing in accordance with ASTM E The design professional shall follow the minimum guidelines set forth in the Progressive Compliance Standards (P.C.S.) for evaluating repairs to existing structures. Design professionals should also specify the attachment of the door frame to the wall (e.g., type, size, spacing, and edge distance of frame fasteners). For sectional and rolling doors attached to wood nailers, design professionals should also specify the attachment of the nailer to the wall. Windows and skylights The IBC requires that windows, curtain walls, and skylight assemblies (i.e., the glazing, frame, and frame attachment to the wall or roof) have sufficient strength to resist the positive and negative design wind pressure. Design professionals should specify that these assemblies comply with ASTM E ASTM E 2112 provides guidance on the design of sealant joints, as well as other information pertaining to the installation of windows. Where water infiltration protection is particularly demanding and important, it is recommended that onsite water infiltration testing in accordance with ASTM E 1105 be specified. Non-load bearing walls, wall coverings, and soffits The IBC requires that soffits, exterior non-load-bearing walls, and wall coverings have sufficient strength to resist the positive and negative design wind pressures. Soffits are an often over-looked and typically vulnerable area of the envelope. Failed soffits may provide a convenient path for wind-driven rain to enter a building, cause significant damage to contents, and potentially lead to structural failures. Soffits can receive either positive or negative pressure and should be adequately fastened. While there is little guidance available on soffit design and testing, FEMA P-55, Section 11.4, and FEMA P-804, Section 4.1.3, contain guidance for soffits in residential Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-6

28 Mitigating High-Wind Hazards applications (including retrofitting measures) that may be adapted to apply to nonresidential buildings. Where corrosion is a problem, stainless steel fasteners are recommended for wall and soffit systems. Exterior non-load-bearing masonry walls should be designed to resist the external and internal loading for C&C in order to avoid collapse. While interior non-load-bearing masonry walls are not required by building codes to be designed to resist wind loads, if the building becomes pressurized due to a breach in the envelope, the interior walls could be subjected to significant loads. It is recommended that non-load-bearing masonry walls adjacent to occupied areas be designed to accommodate loads exerted by a design wind event using the partially enclosed pressure coefficient. Roof systems Roof covering damage has historically been the most frequent and costliest type of wind damage. Post-Katrina, the Port of New Orleans has developed a minimum progressive compliance standard in order to reduce the risk of roof failure. The design professional shall follow the minimum guidelines set forth in Appendix A, the Progressive Compliance Standards (P.C.S.). The IBC requires the load resistance of the roof assembly be evaluated by one of the test methods listed in the IBC. While the IBC does not specify a minimum safety factor, a safety factor of 2 is recommended for the roof system. For more guidance on specific roof coverings, see Section of FEMA Protecting Utilities and Equipment from High-Wind Events Continuity of operations after a high-wind event requires the survival and functionality of critical utilities and equipment at the facility. With regard to high-wind events, roof-top equipment is particularly vulnerable. In addition to impairing the operation of the facility, damaged equipment can detach and become wind-borne missiles and water can enter the facility where equipment was displaced General Rooftop Equipment The most common problems for rooftop equipment typically relate to inadequate equipment anchorage, inadequate strength of the equipment itself, and corrosion. A minimum safety factor of 3 is recommended for rooftop equipment on critical facilities. Loads and resistance should also be calculated for heavy pieces of equipment since the dead load of the equipment is often inadequate to resist the design wind load. The following best practices can be applied to improve the performance of rooftop equipment in high-wind events: Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-7

29 Mitigating High-Wind Hazards Fans: Frequently blown off their curbs because they are poorly attached. Blown-off cowlings can tear roof membranes and break glazing. Unless the fan manufacturer specifically engineered the cowling attachment to resist the design wind load, use cable tie-downs to avoid cowling blow-off. Rooftop ductwork: The best approach to avoiding wind and wind-borne debris damage to rooftop ductwork is to not install it on the roof. If ductwork is installed on the roof, it is recommended that the duct gauge and method of attachment be able to resist the design wind loads. Rooftop-mounted condensers: In lieu of placing rooftop-mounted condensers on wood sleepers resting on the roof, condensers should be anchored to equipment stands. The attachment of the stand to the roof deck also needs to be designed to resist the design loads. Vibration isolators: If vibration isolators are used to mount equipment, only those able to resist design uplift loads should be specified and installed, or an alternative means to accommodate uplift resistance should be provided. Boiler and exhaust stacks: To avoid wind damage to boiler and exhaust stacks, wind loads on stacks should be calculated and guy-wires be designed and constructed to resist the loads. Toppled stacks can allow water to enter the building at the stack penetration, damage the roof membrane, and become wind-borne debris. The guy-wires should be inspected annually to ensure they are taut. Screens: Screens around rooftop equipment are frequently blown away. Screens should be designed to resist the wind load derived from ASCE 7. Since the effect of screens on equipment wind loads is unknown, any equipment attached behind the screens should be designed to resist the design load Signage The design professional shall be responsible that any signage attached to any post or other structure is sufficiently anchored to resist wind load in accordance with ASCE-7-05 or the latest IBC adopted by the PONO Electrical and Communications Equipment Damage to smaller exterior-mounted electrical equipment is infrequent. Larger equipment, such as communication towers, generators, control cabinets, surveillance cameras, electrical service masts, satellite dishes, and lighting protection systems, is typically damaged due to inadequate mounting (and sometimes from corrosion). The design professional shall be responsible that the equipment and any support structures are sufficiently anchored to resist wind load in accordance with ASCE-7-05 or the latest IBC adopted by the PONO. ANSI/C2 provides guidance for determining wind loads on power distribution and transmission poles and towers. AASHTO LTS-4-M (amended by LTS-4-12, 2001 and 2003, respectively) Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-8

30 Mitigating High-Wind Hazards provides guidance for determining wind loads on light fixture poles. Both ASCE 7 and ANSI/TIA-222-G contain wind load provisions for communication towers (structures). The IBC allows the use of either approach. In addition to the disruption of communications, collapsed towers can puncture roof membranes and allow water leakage into facilities, unless the roof system incorporated a secondary membrane. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 3-9

31 References SECTION FOUR: REFERENCES American Society of Civil Engineers (ASCE). 2005a. Minimum Design Loads for Buildings and Other Structures. ASCE Standard ASCE ASCE. 2005b. Flood Resistant Design and Construction. ASCE Standard ASCE ASCE Minimum Design Loads for Buildings and Other Structures. ASCE Standard ASCE City of New Orleans, Louisiana, Code of Ordinances Ordinance No , Article II, Flood Damage Prevention Federal Emergency Management Agency (FEMA) Design Guide for Improving Critical Facility Safety from Flooding and High Winds. FEMA 543. January. FEMA. 2008a. Flood Damage-Resistant Materials Requirements. NFIP Technical Bulletin 2. FEMA 2008b. Design and Construction Guidance for Community Safe Rooms. FEMA P-361. August. FEMA. 2009a. Protecting Manufactured Homes from Floods and Other Hazards. FEMA P-85. FEMA. 2009b. Recommended Residential Construction for Coastal Areas: Building on Strong and Safe Foundations. FEMA P-550. December. FEMA. 2010a. Home Builder s Guide to Coastal Construction Technical Fact Sheet Series. FEMA P-499. December. FEMA 2010b. Wind Retrofit Guide for Residential Buildings. FEMA P-804. December. FEMA Coastal Construction Manual, Fourth Edition. FEMA P-55. August. FEMA Engineering Principles and Practices for Retrofitting Flood-Prone Residential Structures. FEMA P-259. January. ICC Standard for the Design and Construction of Storm Shelters. ICC Birmingham, AL. ICC. 2009a. International Building Code. Birmingham, AL. ICC. 2009b. International Residential Code. Birmingham, AL. ICC. 2009c. International Existing Building Code. Birmingham, AL. ICC. 2009d. International Mechanical Code. Birmingham, AL. ICC. 2009e. International Fuel Gas Code. Birmingham, AL. Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 4-10

32 References ICC. 2009f. International Energy Conservation Code. Birmingham, AL. ICC. 2009g. International Existing Building Code. Birmingham, AL. ICC. 2009h. International Fire Code. Birmingham, AL. Port of New Orleans Board of Commissioners Board of Commissioners Port of New Orleans Hazard Mitigation Plan. October 13, Title 44 of the Code of Federal Regulations (CFR) Section 60.3 (44 CFR 60.3). Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ 4-11

33 Appendix A Appendix A Repair/Replacement Guidelines Flowchart for Wind Damaged Sheds PONO Progressive Compliance Standards 2013 Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix A

34 Appendix A Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix A

35 Appendix B Appendix B Typical PONO Details 2013 Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix B

36 Appendix B Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix B

37 Appendix B Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix B

38 Appendix B Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix B

39 Appendix B Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix B

40 Appendix B Prepared by: MDM Design Group, Inc. & URS 4-SEP-13\\ Appendix B