ADDENDA #4- RFP Sylvania CC building Re-Roof Progressive Design Build for Sylvania Campus CC Building Re-Roof Services

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1 ADDENDA #4- RFP Sylvania CC building Re-Roof Progressive Design Build for Sylvania Campus CC Building Re-Roof Services Addenda Dated: 01/16/2018 PURPOSE: The purpose of this Addenda #4 is to provide a copy of the Seismic Evaluation Report per KPFF (2012), listed as Appendix L on the RFP. The document follows this cover sheet and is attached. End of Cover Sheet for Addenda #4

2 Portland Community College - Sylvania Campus Seismic Evaluation Report - Final January 6, 2012

3 Table of Contents PCC Sylvania Campus Seismic Evaluation Report Executive Summary 1 Site & Building Data 2 ASCE 31 Tier 1 "Screening" 3 Seismic Upgrades 4 Appendix A - Overall Campus Seismic Evaluation Matrix Appendix B - Building Seismic Evaluation Data AM - Automotive & Metals Building CC - Amo DeBernardis College Center CT - Communication Technology Building HP - Heat Plant HT - Health Technology Building SS - Social Science & Technology Building ST - Science & Technology Building A B AM CC CT HP HT SS ST

4 PCC Sylvania Campus Seismic Evaluation Report GBD Architects and KPFF Consulting Engineers were contracted to perform a seismic evaluation of several existing buildings, located at Portland Community College s Sylvania Campus at SW 49th Avenue, in Portland, Oregon. This seismic evaluation includes a narrative description of the structural systems of the building, identification of structural and nonstructural seismic deficiencies, as well as recommendations for possible structural and non-structural voluntary seismic upgrades and rough order of magnitude costs for structural upgrades. The report is intended to provide guidance in planning and prioritizing voluntary seismic upgrades, taking into account the relative risks and upgrade costs associated with the identified seismic deficiencies. The seismic evaluation is based on methods outlined in ASCE Seismic Evaluation of Existing Buildings, which is an industry standard. The seismic evaluation is used to determine if the buildings meet the requirements for the Life Safety performance level, as defined by ASCE 31, and to identify any potential deficiencies. A Tier 1 screening is used to identify any parts of the structure that may be seismically deficient. Parts of the structure that are identified as being deficient are further investigated in a Tier 2 evaluation. As we recommended, we have performed a Tier 1 screening only at this time since we can use these findings to accurately identify most of the existing seismic deficiencies. Executive Summary We performed an ASCE 31 Tier 1 seismic screening for seven of the existing building at the PCC Sylvania Campus. The screening is used to identify structural and non-structural seismic deficiencies relative to the Life Safety performance level, which is equivalent to current building code performance. The existing buildings were built in the 1960 s and the early 1970 s and are constructed of cast in place concrete and in some cases, precast concrete. Since the time of the original construction, building codes have changed dramatically both in how seismic forces are determined and in the reinforcing steel detailing requirements for concrete buildings. It is typical for buildings of this vintage to be seismically deficient unless they have a significant amount of concrete shear walls. Three of the buildings have significant deficiencies in their seismic force resisting systems; these buildings include the Health Technology Building, College Center, and Communication Technology Building. These buildings have minimal and/or poorly connected seismic force resisting elements; we recommend providing new concrete shear walls or buckling restrained braced frames in these buildings. The other four buildings are significantly less deficient and should have a lower priority for structural seismic upgrades as noted in the appendices to this report. We also highly recommend seismically disconnecting the exterior walkway/bridges that connect the Social Science & Technology building with the Science and Technology building. Seismic Evaluation Report 1

5 All of the buildings have some non-structural seismic deficiencies. The most common deficiency is the apparent lack of lateral bracing at the top of interior concrete block partition walls. If further investigation reveals that these walls are unbraced, the walls should be laterally braced to the structure above. Highest priority should be placed on walls adjacent to exits, stairs, and areas with high occupancy. Another common deficiency is the lack of separation between the building structure and non-structural components such as windows and concrete block partitions, which can lead to damage to the non-structural element as the building frame moves in an earthquake. This deficiency can be mitigated by reducing the horizontal building movement by adding shear walls and by replacing any windows adjacent to exits with safety glazing. Additional non-structural seismic deficiencies are noted in the appendices to this report. Site & Building Data The followings seven buildings were included in the seismic evaluation: Automotive & Metals (AM) Amo DeBernardis College Center (CC) Communication Technology (CT) Heat Plant (HP) Health Technology (HT) Social Science & Technology (SS) Science & Technology (ST) CT HT CC ST SS AM HP N PCC Sylvania Campus, Aerial View Seismic Evaluation Report 2

6 A complete list of our findings and building descriptions for each individual building is presented in Appendix B; a matrix summarizing our findings for all of the buildings can be found in Appendix A. ASCE 31 Tier 1 Screening We performed an ASCE 31 Tier 1 Screening as part of this seismic evaluation. The purpose of the Tier 1 screening is to quickly determine which elements of the structural and nonstructural building systems may be deficient with regard to seismic performance. If portions of a building are found to be seismically deficient, a Tier 2 evaluation can be performed for a more detailed investigation. At this point only a Tier 1 screening has been performed. The design earthquake used in ASCE 31 with respect to the Life Safety performance level is the same earthquake that is used in the current building code, which is the 2010 Oregon Structural Specialty Code, based on the 2009 International Building Code. Both standards use seismic maps produced by the U.S Geological Survey in The USGS released the next generation seismic maps in 2008 which have increased the seismic forces by less than 2% at the Sylvania Campus relative to the 2002 values. The 2008 maps are not in effect yet but will be referenced by the next generation of seismic standards. A geotechnical investigation was not performed for this evaluation. However, based on our experience with other projects in the area we have assumed Site Class D soil, which is typical for this area of Portland. We have also assumed that earthquake induced liquefaction is not a concern at the site. The Level of Seismicity for the structure is considered to be High as defined by Section 2.5 of ASCE 31, which is typical for all buildings in Portland. We assumed a Life Safety level of performance, which is typical for nonemergency buildings. The Building Type, which is used to classify the type of seismic force resisting system, was determined separately for each building, as noted in Appendix B. We had access to the original structural drawings for most of the buildings, which we reviewed as part of our investigation. Additionally, we visited the site several times to evaluate the condition of the existing buildings and to verify that the information noted in the drawings appeared to be accurate. During our site visits we were not able to view all structural members and connections since some of the structural frame is concealed by finishes and reinforcing steel in concrete members is completely concealed from view. The Life Safety performance level is equivalent to the level of performance of a building meeting the current building code: LIFE SAFETY PERFORMANCE LEVEL: Building performance that includes damage to both structural and non-structural components during a design earthquake, such that: (a) partial or total structural collapse does not occur, and (b) damage to nonstructural components is non-life-threatening. - ASCE The condition of the existing buildings appeared to be reasonably good. There was some deterioration of the exposed structure as noted in Appendix B as well as a foundation failure at the Health Technology Building which was caused by a pool leak several years ago and has since been repaired. Seismic Evaluation Report 3

7 Seismic Upgrades In the City of Portland, Chapter of the City Code governs the requirements and triggers for seismic upgrades of existing buildings. When a mandatory seismic upgrade is not triggered by new work, a building owner may elect to perform voluntary seismic upgrades at their own discretion, as described in the section below. When a mandatory seismic upgrade is required it may be necessary to seismically upgrade the entire building structure. In order to avoid a mandatory seismic upgrade the following triggers should be avoided: Change of building use to a higher occupancy classification. Increase in occupant load of 150 occupants or more. New building additions that increase the seismic force in any existing element by more than 10%. Alterations to the existing building structure that increase the seismic force in any element or decrease the capacity of any element by more than 10%. Work associated with a voluntary seismic upgrade as described below will not trigger a full building seismic upgrade. Voluntary Seismic Upgrades Voluntary seismic upgrades are performed at the discretion of the building owner. The only limitation on such upgrades is that they do not make any portion of the building worse with respect to seismic performance. Voluntary upgrades can be made to address any deficiencies that the owner chooses, whether they choose to address all or just some of the deficiencies, and they do not need to be full code level upgrades. Voluntary seismic upgrades are still subject to the building permitting process so that the jurisdiction can verify these requirements are met. Recommended Voluntary Structural Upgrades The specific structural upgrades that we recommend are discussed in detail for each building in Appendix B. When structural upgrades require the removal and replacement of nonstructural materials such as walls, ceilings, and floor finishes, or the relocation of existing MEP systems, the total cost of the work can be two to three times the cost of the structural work considered alone. It is therefore desirable to locate any new lateral elements in areas that are readily accessible and in order to minimize any non-structural work. This can be accomplished by locating new lateral elements at the building perimeter or adjacent to existing floor openings such as at atriums or stairs. New lateral elements can also be located next to existing non-structural concrete block walls. New lateral elements should be located in line with existing beam and girder lines in order to minimize the need for new collector elements in the diaphragms. Seismic Evaluation Report 4

8 Phasing of structural improvements within a single building should be carefully considered. In some cases, the construction of a portion of a seismic upgrade can temporarily make the building seismic performance worse until the full upgrade is completed. It is important that a construction phasing plan be designed to minimize or eliminate any such periods of reduced seismic performance in order to allow continued occupation of the building during construction. There are several possible lateral systems that could be used to retrofit the CC, CT, and HT buildings. These systems include concrete shear walls, steel braced frames, and steel buckling restrained braced frames. All of these systems can provide adequate strength to resist current code level seismic forces, and also provide enough stiffness to help mitigate the risk of non-structural damage due to lateral movement. We recommend using either concrete shear walls or buckling restrained braced frames. Concrete shear walls provide greater stiffness, while buckling restrained braced frames are more able to accommodate window and door openings. Buckling restrained braced frames provide excellent ductility and energy dissipation characteristics and represent the current state of the art for seismic force resisting systems. Unlike conventional braced frames, buckling restrained braced frames use special braces designed to yield in compression rather than buckle. The International Building Code recognizes the greater ductility of buckling restrained braced frames as compared to shear walls, and allows a 15% reduction in seismic forces on primary structural components,including the existing floor and roof structures, new foundation elements, and the frames themselves. Portland State University, Lincoln Hall Renovation (Buckling Restrained Brace Frame) Recommended Voluntary Non-Structural Upgrades Concrete Block Partitions: We recommend providing new lateral bracing at the top of existing unbraced concrete block partition walls. We were not able to determine if any connection exists at the top of these walls but it is likely that some of the walls are completely un-braced and some are inadequately braced. We recommend that non-destructive field investigations be performed to determine if there are any connections that are concealed from view. Unbraced walls are at risk of collapse in a major seismic event and should be laterally braced to the structure above or removed. The highest priority should be placed on bracing walls adjacent to exits, stairs, and classrooms; lower priority can be placed on bracing walls adjacent to areas with lower occupancy or rooms that are infrequently occupied such as storage rooms. Seismic Evaluation Report 5

9 Mechanical, Electrical and Plumbing: We did not perform a comprehensive review of all mechanical, electrical and plumbing systems. We did note that some of the equipment located in the Heat Plant was not bolted to the foundation and it is likely that any existing MEP systems installed prior to the 1990 s are not seismically braced. All water heaters should have seismic straps. All mechanical units should be bolted to the supporting structure and suspended mechanical units should be seismically braced to the structure above. Fire sprinkler systems should be braced where required in accordance with NFPA 13, and should be given the highest priority of the MEP systems. Other Non-Structural Elements: ASCE 31 includes checks for many non-structural components that were not readily accessible in our walk-thrus. These include such things as cladding connections which in many cases are hidden from view, bracing of acoustic tile ceilings, independent wire hangers for lights in acoustic tile ceilings, and bracing of tall narrow building contents. Cladding and ceilings should be evaluated and updated to current requirements when new work is performed on an element that is deficient. All tall or narrow contents with a height of over 4 feet or height to width ratio greater than 3:1 should be anchored to the floor slab or structural walls. Seismic Evaluation Report 6

10 Appendix A - Overall Campus Seismic Evaluation Matrix ASCE 31 Tier 1 Seismic Study Matrix AM CC CT HP HT SS ST Primary Structural System Non-Structural Systems Building Seismic Force Resisting System Deficiency Summary Proposed Retrofit Rating - Cost Deficiency Summary Proposed Retrofit Rating Automotive & Metals Amo DeBernardis College Center Communication Technology Heat Plant Health Technology Social Science & Technology Science & Technology Concrete Shear Walls Topping slab diaphragms over precast floor and roof framing Concrete Moment Frames Topping slab diaphragms over precast channel framing Concrete Moment Frames Cast-in-place slab diaphragms Concrete Frame with Infill Masonry Shear Walls Cast-in-place slab diaphragms Concrete Shear Walls and Concrete Frames with Infill Masonry Shear Walls Metal roof deck, cast-in-place and connected precast concrete diaphragms Concrete Moment Frames Topping slab diaphragms over precast channel framing Concrete Moment Frames Topping slab diaphragms over precast channel framing -Overstressed Shear Walls -Overstressed Diaphragms -Deterioration of Concrete and Post-tensioning Anchors -Columns Overstressed in Shear -Inadequate Moment Frame Detailing -Beam Pre-stress Exceeds Allowable for Moment Frames -Diaphragm Discontinuities -No Top Reinforcing in Pile Caps -Torsion -Interfering Walls -Columns Overstressed in Shear -Inadequate Moment Frame Detailing -Un-braced Mezzanine -Vertical Discontinuities -Torsion -Overstressed Shear Walls -Inadequate Wall Anchorage -Add new interior concrete shear walls in both directions -Add 150ft of new 12 thick concrete shear walls or (6) bays of BRB s in each direction, distributed throughout the building -Add 80ft of new 12 thick concrete shear walls or (4) bays of BRB s in each direction -Anchor mezzanine to building exterior walls and screw down plywood decking to steel framing -Add additional shear walls in both directions in the academic wing of building -Retrofit roof level wall connections around gym perimeter 2 1A - $20-30sf 1B - $20-30sf 3 1C - $20-30/sf -No Top Reinforcing in Pile Caps -None proposed 4 -Discontinuities in masonry shear walls -Adjacent Building Separation -Deterioration of Concrete and Post-tensioning Anchors -Interfering Walls -Columns Overstressed in Shear -Inadequate Moment Frame Detailing -Adjacent Building Separation -Deterioration of Concrete and Post-tensioning Anchors -Interfering Walls -Columns Overstressed in Shear -Inadequate Moment Frame Detailing -Infill openings with masonry or concrete -Provide a seismic joint at walkways connecting to the ST building -Add 70ft of new 12 thick concrete shear walls or (4) bays of BRB s in each direction -Provide a seismic joint at walkways connecting to the SS building -Add 80ft of new 12 thick concrete shear walls or (4) bays of BRB s in each direction 2 3 1D - $30-40/sf of walkway 2 1D - $30-40/sf of walkway 2 -Concrete block partition walls are un-braced -Cladding is not isolated from the structural frame -Cladding is not isolated from the structural frame Un-braced and/or un-anchored equipment and piping -Concrete block partition walls are un-braced -Cladding is not isolated from the structural frame -Cladding is not isolated from the structural frame Brace the tops of concrete block partition walls to structure -Add shear walls to reduce the building drift -Add shear walls to reduce the building drift Laterally brace equipment and piping per current code and anchor equipment to bases Brace the tops of concrete block partition walls to structure -Add shear walls to reduce the building drift -Add shear walls to reduce the building drift Legend: 1 Indicates highest priority for retrofit based on life safety deficiencies and cost/benefit. Letter following number 1 indicates order of priority. 2 Indicates lower priority deficiencies that should be corrected. 3 Indicates deficiencies that are relatively low risk. 4 Indicates essentially in conformance with current seismic design standards. BRB4 Cost4 Indicates steel buckling restrained braced frame. Indicates rough order of magnitude cost of structural work only on a gross square footage basis. Total cost including non-structural work may be 2 to 3 times this. Seismic Evaluation Report - Appendix A A

11 Appendix B - Seismic Evaluation Data All buildings in the study were evaluated using an ASCE 31 Tier 1 screening and the following seismic criteria: PCC Sylvania Seismic Data - ASCE 31 Spectral Response Accelerations S S = 0.96 S 1 = 0.34 Soil Factors Site Class D F a = 1.12 F v = 1.72 Design Spectral Response Accelerations S DS = 0.71 S D1 = 0.39 Level of Seismicity High Performance Level Pseudo Lateral Force Calculation* Life Safety *The Pseudo Lateral Force varies for each building. Refer to the building specific sections of this report for the calculated Pseudo Lateral Force. C S a W V = CS aw Definitions: S s, S 1 - Acceleration due to seismic ground motion at 0.2 second and 1 second building periods, expressed as a fraction of the acceleration of gravity. Values for these parameters are mapped by the US Geological Survey; this report is based on the 2002 maps. Site Class D - Classification assigned to a site based on the types of soils present and their engineering properties. Most soils in the Portland area are classified as Site Class C or D; Site Class D soils result in higher seismic demands. Site Class D has been assumed. F a, F v - Site coefficients which modify mapped spectral response parameters based on type of soil present at site. S DS, S D1 - Acceleration parameters used for design, equivalent to 2/3 of the acceleration from the Maximum Considered Earthquake (MCE). The MCE is the earthquake with a 2% probability of exceedence in 50 year: the 2,500 year event. Level of Seismicity - Degree of expected earthquake hazard, classified as low, moderate, or high. All of western Oregon is classified as High, meaning that earthquakes represent a significant hazard. Performance Level - Desired level of performance for a building structure subjected to the design earthquake. The Life Safety level of performance is equivalent to the expected performance of a building designed to meet current code requirements. Life Safety Performance Level includes building damage to both structural and non-structural components, however, the building structure does not collapse and damage to non-structural components is not life threatening. V - Pseudo Lateral Force, the calculated seismic base shear that corresponds to the building deformations expected in the design level earthquake, using an elastic analysis. This force is used in a Tier 1 screening to perform quick checks of the primary lateral force resisting elements. C - Modification factor based on type of building structure and height. S a - Acceleration used in determining Pseudo Lateral Force, expressed as a fraction of the acceleration of gravity. W - Total seismic weight of the building, including structural and non-structural components and a portion of live loading where prescribed by ASCE 31. Areas - Square foot areas noted in "Building Data" tables correspond to the total area of elevated floor and roof structure. Some of the buildings have large roof overhangs that extend over exterior space. The area of structure more accurately reflects the size of the building with respect to seismic performance and cost of seismic upgrades. B

12 AM - Automotive & Metals Building Structural Systems: Gravity: The roof is constructed from pre-stressed, precast channels supported on castin-place beams and columns. The second level is composed of cast-in-place concrete joists spanning between concrete beams and columns. Foundations are conventional spread footings with slab on grade construction. Seismic Force Resisting System: Concrete shear walls are located in the southwest and northeast corners of the building. The roof and floor diaphragm consist of light-weight concrete topping slabs reinforced with wire mesh placed over the structural framing. Condition/Comments: The building exhibited some corrosion at exterior conditions where steel plates embedded in concrete are not protected. There are numerous nonstructural concrete block partition walls that are not seismically braced. ASCE 31 Evaluation Data: The building is classified as Type 9 - Concrete Shear Walls in both directions. The following checklists were evaluated as part of the ASCE Tier 1 screening: Basic Structural Checklist Supplemental Structural Checklist 3.7.9S Geologic Site Hazards and Foundations Checklist 3.8 Basic Non-Structural Checklist Intermediate Non-Structural Checklist Year Constructed Area Footprint Stories Building Data ,000 sf. 205 ft x 160 ft 2 + Penthouse Story Heights 14-6 & 21-3 Building Height Original Code Latitude: Longitude: Penthouse 1964 UBC Seismic Data Pseudo Lateral Force Calculation C = 1.2 S a = 0.72 W = 14,220 k V = CS aw = 12,167 kips AM

13 AM - Automotive & Metals Building (continued) The table below lists only items that were found to be seismically deficient: ASCE 31 Tier 1 Screening - Deficiencies Summary Checklists Non-Conforming Items Description* Structural Geologic Site Hazards and Foundations Nonstructural -Shear Stress Check -Transfer to Shear Walls -No confirmed deficiencies -No confirmed deficiencies -Wall shear stress exceeds allowable stress by 90% -Diaphragm connections are not capable of transferring lateral loads to collectors and shear walls * An ASCE 31 Tier 2 deficiency only evaluation may be performed to further investigate items found to be deficient. Recommendations: The building shear walls did not pass the Tier 1 check for shear stress, however, it appears likely that the walls will meet the Tier 2 requirements, or be only slightly overstressed. The floor diaphragms do not have adequate connections to transfer loading to the shear walls. Retrofitting the diaphragms will be very expensive and it will be more cost effective to add more interior shear walls so that the diaphragm carries less load. The retrofit will be fairly expensive when compared to the marginal benefit it will provide and therefore it is considered a lower priority. The building has numerous un-braced concrete block partition walls. ASCE 31 does not have a check for reinforced walls that are un-braced, however, in order to improve life safety performance we recommend providing bracing at any of these walls that are not currently braced at 10 feet on center maximum. Where walls are braced by return walls spaced at no more than 15 feet on center, bracing will not be required. AM

14 CC Amo DeBernardis College Center Structural Systems: Gravity: The roof is constructed of precast, pre-stressed concrete channels supported by post-tensioned cast-in-place beams and columns. At the center of the building is a raised portion of the roof which consist of twoway cast-in-place concrete slabs supported by concrete walls and beams. Portions of the ground floor over basements are constructed of cast-inplace one-way slabs supported by concrete joists, beams and columns. The building is supported by both piles and spread footing foundations. Seismic Force Resisting System: Lateral forces are resisted by long span concrete moment frames and small pieces of concrete walls. The roof diaphragm is made up of a light-weight concrete topping slab over the precast channels. The topping is doweled directly into the tops of the concrete frame beams. Condition / Comments: Some incidents of corrosion were seen at exterior post-tensioning anchorages and embedded steel plates. Cracking and water penetration is visible in the bottoms of the raised two-way roof slabs at the center of the building. ASCE 31 Evaluation Data: The building is classified as Type 8 - Concrete Moment Frames in both directions. The following checklists were evaluated as part of the ASCE Tier 1 screening: Year Constructed Area Footprint Stories Building Data ,000 s.f. 425 ft x 315 ft 1 + Penthouse & Basements Story Heights 15-8 Building Height Original Code Latitude: Longitude: max UBC Basic Structural Checklist Supplemental Structural Checklist 3.7.8S Geologic Site Hazards and Foundations Checklist 3.8 Basic Non-Structural Checklist Intermediate Non-Structural Checklist Seismic Data Pseudo Lateral Force Calculation C = 1.1 S a = 0.71 W = 27,418 k V = CS aw = 20,277 kips CC

15 CC Amo DeBernardis College Center (continued) The table below lists only items that were found to be seismically deficient: ASCE 31 Tier 1 Screening - Deficiencies Summary Checklists Non-Conforming Items Description* -Deterioration of Concrete -Cracking and water penetration visible in bottom of high two-way slabs at building center Structural Geologic Site Hazards and Foundations Nonstructural -Corrosion of Post-Tensioning Anchors -Shear Stress in Columns -Concrete Columns -Pre-stressed Frame Elements -Frame Shear Failures -Strong Column / Weak Beam -Column and Beam Bar Splices -Stirrup and Tie Spacing -Diaphragm Discontinuity -No Pile Cap Top Bar Reinforcing -No deficiencies confirmed -Cladding Isolation -Some exterior post-tensioning anchors have begun to corrode -Columns are overstressed in shear by 20% -A number of columns are not dowelled into the foundations and cannot resist lateral shears -Some post-tensioned beams have average prestresses exceeding the recommended values for moment frames -Some columns will fail in shear before failing in flexure -The frame members do not meet the strong column / weak beam criteria -Column and beam bar splices have inadequate lap lengths and/or laps occur within areas of plastic hinging -Beam stirrup and column tie spacing do not meet requirements for ductility -The raised portions of the roof at the center of the building create a discontinuity in the roof diaphragm -Pile caps do not have top reinforcing for resisting uplift -Cladding is not isolated from the structural frame in order to accommodate building drift * An ASCE 31 Tier 2 deficiency only evaluation may be performed to further investigate items found to be deficient. CC

16 CC Amo DeBernardis College Center (continued) Recommendations: Further investigation should be made into the cause of cracking observed at the raised bay two-way roof slabs to determine whether strengthening is necessary. Corroded post-tensioning anchors should be repaired to prevent further damage. We recommend that a contractor who has experience in post tensioning repairs be hired to evaluate the extent of damage and develop a repair plan. Due to the high number of deficiencies found with the existing moment frame system and the difficulty in retrofitting the frames to meet acceptable standards, we recommend converting the building lateral system to a concrete shear wall or buckling restained braced frame building by adding new lateral elements throughout the building in both directions. The few existing walls within the building could be extended/thickened or otherwise used in conjunction with the new lateral elements to resist lateral forces. New lateral elements can be strategically located within the existing layout to minimize occupant disruption. Approximately 150 feet of 12 thick walls in each direction would be required or 6 bays of buckling restrained braced frames. Attempting to retrofit the moment frame system would require work to be performed on every beam and every column with significant expense and disruption to occupants. The diaphragm discontinuity created by the raised roof bays at the center of the building can be considered a low priority due to the localized nature of the discontinuity and the presence of concrete walls and beams that should be capable of transferring diaphragm loads down to the main roof diaphragm. The absence of top reinforcing bars in the pile caps would no longer be a concern once the building was converted to a shear wall building, except possibly at pile caps located at the ends of new lateral elements. These individual pile caps would only be retrofitted if further analysis determines that uplift resistance is required at lateral elements. Adding shear walls will stiffen the structure and reduce the expected building movements during a seismic event. Thus, cladding isolation would be much less of a concern once the building is seismically upgraded. Due to the high number and severity of the deficiencies found, and the high level of occupancy and use of the building, this retrofit should be considered highest priority. CC

17 CT Communication Technology Building Structural Systems: Gravity: The roof and second floor levels are constructed of cast-in-place one-way concrete slabs and joists supported on concrete beams and columns. The building is supported on spread footing foundations. Seismic Force Resisting System: Lateral forces are resisted by concrete moment frames in each direction. The diaphragms consist of the cast-in-place slabs. Diaphragms are connected to the frame beams either by dowels or beam stirrups extending up into slabs or joists. Two exterior concrete walls are located on the east face of the building at the second level. Several interior concrete walls are located in the northwestern portion of the building at ground level only. Year Constructed Area Building Data ,000 s.f. Condition / Comments: Footprint 230 ft x 190 ft The building appears to be in good condition. No obvious signs of corrosion or damage were discovered. There are many beam penetrations for mechanical distributions systems throughout the second floor framing which appear on the structural drawings. There are numerous concrete block partition walls on the ground level that do not appear to be seismically braced. ASCE 31 Evaluation Data: Stories 2 Story Heights 14-6 Building Height 29-0 Original Code Latitude: Longitude: UBC The building is classified as Type 8 - Concrete Moment Frames in both directions. The following checklists were evaluated as part of the ASCE Tier 1 screening: Basic Structural Checklist Supplemental Structural Checklist 3.7.8S Geologic Site Hazards and Foundations Checklist 3.8 Basic Non-Structural Checklist Intermediate Non-Structural Checklist Seismic Data Pseudo Lateral Force Calculation C = 1.1 S a = 0.63 W = 14,723 k V = CS aw = 10,213 kips CT

18 CT Communication Technology Building (continued) The table below lists only items that were found to be seismically deficient: ASCE 31 Tier 1 Screening - Deficiencies Summary Checklists Non-Conforming Items Description* -Torsion -Shear walls located on only one face of the building in only one direction could cause the building to twist under lateral loading Structural Geologic Site Hazards and Foundations Nonstructural -Interfering Walls -Shear Stress in Columns -Frame Shear Failures -Strong Column / Weak Beam -Column and Beam Bar Splices -Stirrup and Tie Spacing -Joint Reinforcing -No deficiencies confirmed -Cladding Isolation -Concrete and masonry infill walls are not isolated from the structural frame -Columns are overstressed in shear by 140% -Columns will fail in shear before failing in flexure -The frame members do not meet the strong column / weak beam criteria -Column and beam bar splices have inadequate lap lengths and/or laps occur within areas of plastic hinging -Beam stirrup and column tie spacing do not meet requirements for ductility -Beam/column joints do not have ties -Cladding is not isolated from the structural frame in order to accommodate building drift * An ASCE 31 Tier 2 deficiency only evaluation may be performed to further investigate items found to be deficient. CT

19 CT Communication Technology Building (continued) Recommendations: Due to the high number of deficiencies found with the existing moment frame system and the difficulty in retrofitting the frames to meet acceptable standards, we recommend converting the building lateral system to a concrete shear wall or buckling restrained braced frame building by adding new lateral elements on the north, south and west sides of the building. The few existing walls within the building could be used in conjunction with the lateral elements to resist lateral forces more efficiently. New lateral elements can be strategically located within the existing layout to minimize occupant disruption. Approximately, 80 feet of 12 thick walls in each direction or 4 bays of buckling restrained braced frames would be required. This upgrade will address all structural and non-structural deficiencies found during this study. Attempting to retrofit the moment frame system would require work to be performed on every beam and every column with significant expense and disruption to occupants. Adding lateral elements will stiffen the structure and reduce the expected building movements during a seismic event. Thus, cladding isolation no longer is an issue once the building is seismically upgraded. Due to the high number and severity of the deficiencies found, and the level of occupancy and use of the building, this retrofit should be considered a high priority. CT

20 HP - Heat Plant Structural Systems: Gravity: The second level and roof consist of cast-in-place one way slabs with joists supported by concrete beams and columns. There is a light weight concrete topping at both levels. A newer steel framed mezzanine with light gage joists and plywood decking is located in the southernmost bay of the building. Foundations types could not be determined due to the lack of accessible structural drawings. Seismic Force Resisting System: Lateral forces are resisted by a concrete frame with infill masonry shear walls at the building exterior. Condition / Comments: The building structure seemed to be in good condition. There are nonstructural concrete block partition walls that are not seismically braced. The building contains numerous pieces of equipment that were not anchored down as well as an abundance of piping hung from the walls and ceiling that did not appear to be seismically braced. The steel framed mezzanine did not appear to be braced independently from the building. ASCE 31 Evaluation Data: The building is classified as Type 10 - Concrete Frames with Infill Masonry Shear Walls in both directions. The following checklists were evaluated as part of the ASCE Tier 1 screening: Year Constructed Area Footprint Stories Building Data ,400 s.f. 120 ft x 50 ft 2 w/ mezzanines Story Heights 14-6 & 14-1 Building Height 28-7 Original Code Latitude: Longitude: UBC Basic Structural Checklist Supplemental Structural Checklist S Geologic Site Hazards and Foundations Checklist 3.8 Basic Non-Structural Checklist Intermediate Non-Structural Checklist Seismic Data Pseudo Lateral Force Calculation C = 1.2 S a = 0.71 W = 2,585 k V = CS aw = 2,212 kips HP

21 HP - Heat Plant (continued) The table below lists only items that were found to be seismically deficient: ASCE 31 Tier 1 Screening - Deficiencies Summary Checklists Non-Conforming Items Description* Structural Geologic Site Hazards and Foundations Nonstructural -Mezzanines -No deficiencies confirmed -Tall Narrow Contents -Attached Equipment * An ASCE 31 Tier 2 deficiency only evaluation may be performed to further investigate items found to be deficient. -The steel mezzanine is not independently braced or tied into the building lateral system -Equipment and other building contents over 4 feet high with a height-to-depth ratio greater than 3 are not anchored to structure -Equipment weighing over 20 lbs suspended 4 feet or higher above the floor level is not braced Recommendations: The steel framed mezzanine should be tied or anchored to the adjacent exterior walls and the plywood decking should be screwed down to the supporting light gage joists and steel beams. This upgrade would be relatively inexpensive and easy to perform. Non-structural elements such as mechanical equipment and piping should be anchored or braced as required by current code. Large mechanical equipment over 4 feet in height such as the boiler should be anchored to the base slab. The building has numerous un-braced concrete block partition walls. ASCE 31 does not have a check for reinforced walls that are un-braced, however, in order to improve life safety performance we recommend providing bracing at any of these walls that are not currently braced at 10 feet on center maximum. Where walls are braced by return walls spaced at no more than 15 feet on center, bracing will not be required. Due to the fact that the Heat Plant has a low number of occupants at any one time, the deficiencies found during this Tier 1 evaluation pose a low level of threat to life safety. Therefore, addressing these deficiencies is considered a lower priority. HP

22 HT - Health Technology Building Structural Systems: Gravity: The roof over the academic portion of the building is constructed from castin-place two-way waffle slabs and one-way joists and beams supported by concrete columns. The roof over the gym portion of the building is composed of steel wide flange and plate girder framing supporting a metal roof deck. The roof over the swimming pool is composed of precast, prestressed concrete channels supports by bearing walls along the gym and concrete beams and columns along the south side. The intermediate levels consist of cast-in-place two-way waffle slabs and one-way concrete joists spanning between concrete beams and columns. Concrete encased steel friction piles and larger diameter caissons with sockets into rock are used for the building foundations. Seismic Force Resisting System: Concrete shear walls are located throughout the building with walls around the perimeter of the gym and stair shafts, and individual walls within the academic portion of the building. The roof and floor diaphragm in the academic wing are cast-in-place concrete slabs. In the gym portion of the building, the roof diaphragm is a 1½ deep metal roof deck while the gym floor diaphragms are cast-in-place waffle slabs. The pool area has portions of exterior masonry infill that laterally support the structure on the south, east and west sides. The roof diaphragm is composed of precast channels locked together with intermittent welded connections. Year Constructed Area Footprint Building Data ,000 s.f. 340 ft x 230 ft Stories 4 Story Heights 14-6 typ. Building Height 43-6 Original Code Latitude: Longitude: UBC Condition/Comments: The building exhibited minor corrosion at exterior conditions where steel plates embedded in concrete are not protected. There are numerous nonstructural concrete block partition walls that may not be seismically braced. ASCE 31 Evaluation Data: The building is classified as Type 9 - Concrete Shear Walls in both directions. The pool portion of the building was also classified as Type 10 Concrete Frames with Infill Masonry Shear Walls. The following checklists were evaluated as part of the ASCE Tier 1 screening: Basic Structural Checklists 3.7.9, 3.7.9A and Supplemental Structural Checklists 3.7.9S, 3.7.9AS and S Geologic Site Hazards and Foundations Checklist 3.8 HT

23 HT - Health Technology Building (continued) Seismic Data Pseudo Lateral Force Calculation C = 1.0 S a = 0.71 W = 33,296 k V = CS aw = 23,740 kips The table below lists only items that were found to be seismically deficient: ASCE 31 Tier 1 Screening - Deficiencies Summary Checklists Non-Conforming Items Description* -Vertical Discontinuities -A shear wall within the academic portion of the building is not continuous from foundation to roof Structural Geologic Site Hazards and Foundations Nonstructural -Torsion -Shear Stress Check -Wall Anchorage -Uplift at Pile Caps -Infill Walls -No confirmed deficiencies -No confirmed deficiencies -Lateral stiffness differences between the gym and the academic wing may cause the building to twist during a seismic event -Concrete and masonry shear walls are overstressed -The gym roof diaphragm connections to the concrete perimeter walls are inadequate for wall out-of-plane forces -Pile caps do not have top bar reinforcing for resisting uplift -Some of the masonry infill walls on the west side of the pool are not continuous (i.e. they contain door openings) * An ASCE 31 Tier 2 deficiency only evaluation may be performed to further investigate items found to be deficient. HT

24 HT - Health Technology Building (continued) Recommendations: The building shear walls did not pass the Tier 1 check for shear stress, however, it appears likely that the walls around the pool and gym will meet the Tier 2 requirements or be only slightly overstressed. The academic wing of the building does not have any shear walls in the east-west direction and one of the north-south direction walls is discontinuous at the ground floor. New shear walls should be added within the academic wing in each direction in order to both reduce shear stresses in the walls and reduce building torsion during a seismic event. Since there are already numerous concrete shear walls in this building and the building is very heavy, we do not recommend buckling restrained braced frames since they will not provide adequate stiffness for this building. The roof diaphragm to shear wall connections at the gym are less than 10% over-stressed. The cost of retrofitting these connections would be significant in comparison to the marginal benefits and therefore is not a high priority. Pile caps are generally only located at the west side of the gym where large uplift forces would not be expected due to the long shear wall lengths. Costs to retrofit these pile caps would be high. Therefore, the absence of pile cap top reinforcing bars is not worth addressing through a voluntary upgrade. The discontinuities created by doorways in the masonry infill shear walls at the west side of the pool could easily be fixed if the doors could either be eliminated or relocated by infilling the openings. The building has numerous concrete block partition walls especially in the bathrooms around the locker room areas. ASCE 31 does not have a check for reinforced walls that are un-braced, however, in order to improve life safety performance we recommend investigating the presence of bracing and providing bracing at any of these walls that are not currently braced at 10 feet on center maximum. Where walls are braced by return walls spaced at no more than 15 feet on center, bracing will not be required. HT

25 SS - Social Science & Technology Building Structural Systems: Gravity: The second and roof levels are constructed of precast, pre-stressed concrete channels supported by cast-in-place concrete beams and columns. The building is supported on spread footing foundations. Seismic Force Resisting System: Lateral forces are resisted by concrete moment frames in each direction. The diaphragms consist of the cast-in-place topping slabs poured over the precast channels. Diaphragms are connected to the frame beams either by dowels through the channels or welded embeds between the beams and channels. Condition / Comments: At numerous locations along the exterior walkways, reinforcing is exposed at the bottom and ends of the precast channels. It appears that attempts have been made to coat the exposed reinforcement to prevent further corrosion. Corrosion was also noted between the ends of two precast channels on the north side near the CC building where it appears that water has been running through the joint. The building is rigidly connected to the Science and Technology Building by four bridging walkways composed of the same typical precast channel construction as the rest of the building. Throughout the building, concrete block partition walls do not appear to be seismically braced. Year Constructed Area Footprint Stories Building Data ,000 s.f. 190 ft x 150 ft 2 + Penthouse Story Heights 14-6 Building Height Original Code Latitude: Longitude: Penthouse 1964 UBC ASCE 31 Evaluation Data: The building is classified as Type 8 - Concrete Moment Frames in both directions. The following checklists were evaluated as part of the ASCE Tier 1 screening: Basic Structural Checklist Supplemental Structural Checklist 3.7.8S Geologic Site Hazards and Foundations Checklist 3.8 Basic Non-Structural Checklist Intermediate Non-Structural Checklist SS

26 SS - Social Science & Technology Building (continued) Seismic Data Pseudo Lateral Force Calculation C = 1.1 S a = 0.63 W = 11,598 k V = CS aw = 8,038 kips The table below lists only items that were found to be seismically deficient: ASCE 31 Tier 1 Screening - Deficiencies Summary Checklists Non-Conforming Items Description* -Adjacent Building Separation -Four walkways rigidly connect to the adjacent ST building Structural Geologic Site Hazards and Foundations Nonstructural -Deterioration of Concrete -Post-Tensioning Anchor Corrosion -Interfering Walls -Shear Stress in Columns -Strong Column / Weak Beam -Beam Bar Splices -Column Tie Spacing -No deficiencies confirmed -Cladding Isolation -Numerous locations of exposed reinforcement and minor corrosion -Several locations where the pre-stressing strand ends have been exposed and corroded -Masonry infill walls are not isolated from the concrete frames -Columns are overstressed in shear by 100% -The frame members do not meet the strong column / weak beam criteria -Beam bar splices have inadequate lap lengths and/or laps occur within areas of plastic hinging -Column ties do meet spacing requirements for ductility -Cladding is not isolated from the structural frame in order to accommodate building drift * An ASCE 31 Tier 2 deficiency only evaluation may be performed to further investigate items found to be deficient. SS

27 SS - Social Science & Technology Building (continued) Recommendations: The SS and ST buildings vary in height and will behave differently under seismic loading. Therefore, it is important that the two buildings be seismically isolated from each other by disconnecting the four rigid walkways connecting the buildings and providing an adequate seismic separation joint. It is anticipated that even a moderate seismic event could cause significant structural damage and threat to life safety if the buildings are not separated. Therefore, this item should take high priority. We recommend providing seismic joint on one end of the walkways only; they would remain rigidly connected on the opposite side. The work would require providing a new concrete columns to support the walkway adjacent to the new seismic joint. The joint would be approximately 3 to 4 inches in width and would require a new ADA compliant seismic joint cover. The cause of concrete deterioration and anchor corrosion should be investigated and steps taken to prevent further damage. Exposed reinforcement and anchors should be covered with a concrete patching compound. Due to the deficiencies found with the existing moment frame system and the difficulty in retrofitting the frames to meet acceptable standards, we recommend adding 70 feet of new 12 thick shear walls or 4 bays of buckling restrained braced frames in each direction. New lateral elements can be strategically located within the existing layout to minimize occupant disruption. Currently, there are two 40 foot wide exterior bays filled solid with brick in each direction. New lateral elements could be added at these locations without entering the building or affecting the building occupants. This proposed seismic upgrade will address all other structural and nonstructural deficiencies found during this study. Attempting to retrofit the moment frame system would require work to be performed on every beam and every column with significant expense and disruption to occupants. Adding lateral elements will stiffen the structure and reduce the expected building movements during a seismic event. Thus, cladding isolation no longer is an issue once the building is seismically upgraded. The deficiencies found in the moment frames are not as severe as those found in other moment frame buildings evaluated as part of this study, therefore the addition of new lateral elements should be considered a lower priority than for the other buildings. SS

28 ST - Science & Technology Building Structural Systems: Gravity: The second and roof levels are constructed of precast, pre-stressed concrete channels supported by cast-in-place concrete beams and columns. The building is supported on spread footing foundations. Seismic Force Resisting System: Lateral forces are resisted by concrete moment frames in each direction. The diaphragms consist of the cast-in-place topping slabs poured over the precast channels. Diaphragms are connected to the frame beams either by dowels through the channels or welded embeds between the beams and channels. Condition/Comments: At numerous locations along the exterior walkways, reinforcing is exposed at the bottom and ends of the precast channels. It appears that attempts have been made to coat the exposed reinforcement to prevent further corrosion. Corrosion was also noted between the ends of two precast channels on the north side near the CC building where it appears that water has been running through the joint. The building is rigidly connected to the Science and Technology Building by four bridging walkways composed of the same typical precast channel of construction as the rest of the building. Throughout the building, concrete block partition walls do not appear to be seismically braced. Year Constructed Area Footprint Stories Building Data ,000 s.f. 190 ft x 150 ft 3 + Penthouse Story Heights 14-6 Building Height Original Code Latitude: Longitude: Penthouse 1964 UBC ASCE 31 Evaluation Data: The building is classified as Type 8 - Concrete Moment Frames in both directions. The following checklists were evaluated as part of the ASCE Tier 1 screening: Basic Structural Checklist Supplemental Structural Checklist 3.7.8S Geologic Site Hazards and Foundations Checklist 3.8 Basic Non-Structural Checklist Intermediate Non-Structural Checklist ST