FORM 1 CERTIFICATE OF SEISMIC PERFORMANCE ......certificate, and I have no ownership interest in the property identified above. My scope of review to support the completion of this

Campus: UC Berkeley

Building Name: Hearst Memorial Gymnasium

CAAN ID: 1372

Auxiliary Building ID: N/A Date: 7/11/2019

FORM 1

CERTIFICATE OF SEISMIC PERFORMANCE LEVEL

☒ UC-Designed & Constructed Facility

☐ Campus-Acquired or Leased Facility

BUILDING DATA


Address: Core Campus, Berkeley, 94720

Site location coordinates: Latitude 37.869167 o Longitudinal -122.256667 o

UCOP SEISMIC PERFORMANCE LEVEL (OR “RATING”): V

ASCE 41-17 Model Building Type:

a. Longitudinal Direction: C2: Reinforced Concrete Shear Walls

b. Transverse Direction: C2: Reinforced Concrete Shear Walls

Gross Square Footage: 124,703 sq. ft. (UCB Records)

Number of stories above grade: 2

Number of basement stories below grade: 1 (partial basement)

Year Original Building was Constructed: 1926 (assumed) 1927 (UCB Records)Original Building Design Code & Year: Prior to Building Code

Retrofit Building Design Code & Year (if applicable): Expansion in 1957 (1955 UBC assumed)

SITE INFORMATION

Site Class: C Basis: Geologic Hazards and Site Classification, GeoMatrix Plate 2

Geologic Hazards:

Fault Rupture: No Basis: Earthquake Zones of Required Investigation- Oakland West Quadrangle

https://maps.conservation.ca.gov/cgs/informationwarehouse/regulatorymaps/

Liquefaction: No Basis: Earthquake Zones of Required Investigation- Oakland West Quadrangle


Landslide: No Basis: Earthquake Zones of Required Investigation- Oakland West Quadrangle


ATTACHMENT

Seismic Evaluation: Hearst Memorial Gymnasium, University of California, Berkeley, Rutherford +

Chekene, October 29, 2018, ASCE 41-13.

Campus: UC Berkeley


CAAN ID: 1372


CERTIFICATION & PRESUMPTIVE RATING VERIFICATION STATEMENT

I, Bret Lizundia, a California-licensed structural engineer, am responsible for the completion of this

certificate, and I have no ownership interest in the property identified above. My scope of review to

support the completion of this certificate included both of the following (“No” responses must include an

explanation):

a) the review of structural drawings indicating that they are as-built or record drawings, or that they

otherwise are the basis for the construction of the building: � Yes ☐ No

b) visiting the building to verify the observable existing conditions are reasonably consistent with those

shown on the structural drawings: � Yes ☐ No

Based on my review, I have verified that the UCOP Seismic Performance Level (SPL) is presumptively

permitted by the following UC Seismic Program Guidebook provision (choose one of the following):

☐ 1) Contract documents indicate that the original design and construction of the aforementioned

building is in accordance with the benchmark design code year (or later) building code seismic design

provisions for UBC or IBC listed in Table 1 below.

� 2) The existing SPL rating is based on an acceptable basis of seismic evaluation completed in 2006 or

later. Note: Based on an ASCE 41-17 Tier 3 nonlinear analysis, the October 29, 2018 report assigns a

Seismic Performance Rating of Level V to the existing structure.

☐ 3) Contract documents indicate that a comprehensive1 building seismic retrofit design was fully-

constructed with an engineered design based on the 1997 UBC/1998 or later CBC, and (choose one of the

following):

☐ the retrofit project was completed by the UC campus. Further, the design was based on ground

motion parameters, at a minimum, corresponding to BSE-1E (or BSE-R) and BSE-2E (or BSE-C) as

defined in ASCE 41, or the full design basis ground motion required in the 1997 UBC/1998 CBC or later

for EXISTING buildings, and is presumptively assigned an SPL rating of IV.

☐ the retrofit project was completed by the UC campus. Further, the design was based on ground

motion parameters, at a minimum, corresponding to BSE-1 (or BSE-1N) and BSE-2 (or BSE-2N) as

defined in ASCE 41, or the full design basis ground motion required in the 1997 UBC/1998 or later CBC

for NEW buildings, and is presumptively assigned an SPL rating of III.

☐ the retrofit project was not completed by the UC campus following UC policies, and is presumptively

assigned an SPL rating of IV.

1 A comprehensive retrofit addresses the entire building structural system as indicated by the associated seismic evaluation, as opposed to

addressing selective portions of the structural system.

Campus: UC Berkeley


CAAN ID: 1372


07-15-19

CERTIFICATION SIGNATURE

Bret Lizundia Executive Principal

AFFIX SEAL HERE

Print Name Title

S3950

12/31/2020

CA Professional Registration No. License Expiration Date

Signature Date

Rutherford + Chekene

375 Beale Street, Suite 310

San Francisco, CA 94105-2066

415-568-4400

Firm Name, Phone Number, and Address

07-15-2019

Campus: UC Berkeley


CAAN ID: 1372


Table 1: Benchmark Building Codes and Standards

UBC IBC

Wood frame, wood shear panels (Types W1 and W2) 1976 2000

Wood frame, wood shear panels (Type W1a) 1976 2000

Steel moment-resisting frame (Types S1 and S1a) 1997 2000

Steel concentrically braced frame (Types S2 and S2a) 1997 2000

Steel eccentrically braced frame (Types S2 and S2a) 1988g 2000

Buckling-restrained braced frame (Types S2 and S2a) f 2006

Metal building frames (Type S3) f 2000

Steel frame with concrete shear walls (Type S4) 1994 2000

Steel frame with URM infill (Types S5 and S5a) f 2000

Steel plate shear wall (Type S6) f 2006

Cold-formed steel light-frame construction—shear wall system (Type CFS1) 1997h 2000

Cold-formed steel light-frame construction—strap-braced wall system (Type CFS2) f 2003

Reinforced concrete moment-resisting frame (Type C1)i 1994 2000

Reinforced concrete shear walls (Types C2 and C2a) 1994 2000

Concrete frame with URM infill (Types C3 and C3a) f f

Tilt-up concrete (Types PC1 and PC1a) 1997 2000

Precast concrete frame (Types PC2 and PC2a) f 2000

Reinforced masonry (Type RM1) 1997 2000

Reinforced masonry (Type RM2) 1994 2000

Unreinforced masonry (Type URM) f f

Unreinforced masonry (Type URMa) f f

Seismic isolation or passive dissipation 1991 2000

Note: UBC = Uniform Building Code . IBC = International Building Code .a Building type refers to one of the common building types defined in Table 3-1 of ASCE 41-17.b Buildings on hillside sites shall not be considered Benchmark Buildings.c not usedd not usede not usedf No benchmark year; buildings shall be evaluated in accordance with Section III.J.

h Cold-formed steel shear walls with wood structural panels only.i Flat slab concrete moment frames shall not be considered Benchmark Buildings.

Building Seismic Design Provisions

g Steel eccentrically braced frames with links adjacent to columns shall comply with the 1994 UBC Emergency Provisions, published September/October

1994, or subsequent requirements.

Building Typea,b

Note: This table has been adapted from ASCE 41-17 Table 3-2. Benchmark Building Codes and Standards for Life Safety Structural Performed at BSE-1E.

Seismic Evaluation of

Hearst Memorial Gymnasium University of California, Berkeley

Final Report

29 October 2018

Prepared by:

Rutherford + Chekene

375 Beale Street, Suite 310, San Francisco, CA 94105

415-568-4400

Seismic Evaluation of

Hearst Memorial Gymnasium University of California, Berkeley

Prepared by:

RUTHERFORD + CHEKENE

29 October 2018

Seismic Evaluation of Hearst Memorial Gymnasium – Final Report 29 October 2018

University of California, Berkeley Page i

EXECUTIVE SUMMARY

The Hearst Memorial Gymnasium is rated “POOR” per the 1997 Campus-wide Seismic

Assessment Program (POOR is equivalent to Expected Seismic Performance Level V in UCOP’s

current Seismic Safety policy). . This rating was confirmed by a seismic evaluation in 2005 by

Rutherford + Chekene.

The purpose of this Study was to update and refresh the 2005 Study by performing a more

detailed nonlinear analysis of the building and to propose a cost effective retrofit solution to

improve the building’s expected seismic performance to UCOP Seismic Performance Level III.

Following is a summary of the critical structural deficiencies identified by this study, and the

proposed retrofit: (A detailed presentation of structural assessment results and proposed retrofit

measures are provided in the body of the report).

1. Shear walls at many locations do not extend down to the foundation. These discontinuous

walls cause unacceptable overstressed conditions at floor diaphragms and at columns, and

floor beams directly below the discontinuous walls.

Proposed retrofit measure: Concrete walls are added at strategic locations along the lines

of discontinuous walls; concrete collectors are added to distribute diaphragm forces to the

concrete walls; columns’ axial load capacity and ductility are improved by wrapping them

with composite fiber; beams’ shear capacity is improved with use of composite fiber.

2. Interior gravity columns between Ground Level and Main Level have inadequate capacity

to endure lateral movements during a major earthquake.

Proposed retrofit measure: Columns capacity will be improved by wrapping them with

composite fiber.

3. Roof skylights weaken the roof diaphragm at several locations. The Main Level diaphragm

and floor beams around the main pool area are also critically overstressed.

Proposed retrofit measure: Several options are provided for roof diaphragm strengthening

as discussed in the body of the report. Main Level diaphragm and connecting beams to

pool walls are strengthened using composite fibers.

4. There is an inadequate connection of perimeter concrete walls along the east and

central/south areas of the building to the foundation.

Proposed retrofit measure: New concrete foundation ties are provided to connect the

existing walls to existing footings.

5. At the Main Level, the historic bleachers and planters will overstress the supporting floor

structure in a major seismic event.

Proposed retrofit measure: Beams’ capacity is improved with use of composite fiber.


University of California, Berkeley Page ii

6. Mitigation of Corrosion: In 1994, corrosion in selected areas under the Main and Ground

Levels, surrounding the three pools, was repaired. Similar repair will be implemented in

the remaining areas where repair was not performed in 1994, most importantly the pool

filter room where extensive corrosion of beams and columns are observed. Enclosed spaces

around the pools will be properly ventilated to prevent stagnation of chloride vapor in the

building.

7. Nonstructural Deficiencies: The Hearst Gymnasium possesses several instances of applied

and freestanding decorative elements that are non-structural, such as column capitals,

cornices, balustrades, and statuary. A high-level visual inspection of these historically

significant elements suggests that many of them are delaminating from the primary

structure or exhibit corrosion to the extent that they pose hazardous conditions. A

comprehensive survey and strategy of remedying these decorative non-structural elements

was beyond the breath of the seismic study, however, identifying and addressing these

elements is recommended in order to arrest exposure of structural elements such as steel

reinforcement where the applied items have failed, and to mitigate hazards where these

deteriorating items are proximate to the public. This work is recommended to occur in

advance and independent of a future seismic project. The survey should comprise close

visual and physical inspection (sounding/tapping) of the applied and freestanding elements

via a lift, and subsequent documentation of repairs, stabilization strategies, or else

reproduction of character-defining elements.


University of California, Berkeley Page iii

TABLE OF CONTENTS

EXECUTIVE SUMMARY ........................................................................................................... i

TABLE OF CONTENTS ............................................................................................................ iii

INTRODUCTION......................................................................................................................... 1

BUILDING DESCRIPTION ....................................................................................................... 2

Location and General Description .............................................................................................. 2

Structural System ........................................................................................................................ 3

Existing Material Properties: ...................................................................................................... 5

SEISMIC EVALUATION OF STRUCTURAL ELEMENTS ................................................. 6

Assessment/Retrofit Criteria ....................................................................................................... 6

Seismic Ground Motion Spectra ................................................................................................. 8

Analysis Modeling Assumptions ................................................................................................ 9

Key Building Data .................................................................................................................... 10

Analysis Results ........................................................................................................................ 12

Summary of Structural Deficiencies ......................................................................................... 29

CONCEPTUAL SEISMIC STRENGTHENING RECOMMENDATIONS FOR

STRUCTURAL ELEMENT ...................................................................................................... 31

Analysis Of The Retrofitted Structure ...................................................................................... 32

Additional Analysis In Response to SRC Comments ............................................................... 34

Strengthening Recommendations ............................................................................................. 35

APPENDICES

Structural Appendix 1 – Material Testing and Site Investigation Report from 2005

Structural Appendix 2 – Geotechnical Information Gathered from Surrounding Sites

Structural Appendix 3 – Memo to Seismic Review Committee


University of California, Berkeley Page 1

INTRODUCTION

Rutherford+ Chekene (R+C), as a consultant to Fernau & Hartman Architects, studied the

seismic behavior of the Hearst Memorial Gymnasium and proposed a cost effective retrofit

solution to improve the building’s expected seismic performance to UCOP Seismic Performance

Level III.

This Study is part of a larger study led by Fernau & Hartman Architects to identify and address

facility’s deficiencies (seismic, code, access, infrastructure) and to propose opportunities for

improvements to the program space to accommodate future needs for enrollment/ teaching/

academic space, and redevelopment opportunities to accommodate different occupancies

(theatre, dance, wellness center, etc.).

The building is primarily used as a gymnasium. It contains three pools and also houses offices

for various organizations on the campus. The building rating is “POOR” per the 1997 Campus-

wide Seismic Assessment Program, which was confirmed by the R+C’s 2005 seismic study.

The purpose of this study is to refresh 2005 study, that used linear dynamic procedures, by

modeling the building nonlinearly in PERFORM 3D and performing a pushover analysis. The

main objective of the nonlinear model is to capture the behavior of wall piers between Ground

and Main Levels and the effect of discontinuous walls on the Main Level diaphragm.

Seismic Evaluation of Hearst Memorial

University of California, Berkeley

BUILDING DESCRIPTION

LOCATION AND GENERAL DESCRIPTION

The Hearst Memorial Gymnasium is a two

building, constructed in circa 1926, is a historic structure listed on the national register. The

building is located on a sloping site with grade sloping down to

situated along Bancroft Way, is neighboring Barrows Hall to the northwest and the Music

Building to the northeast. An aerial view of the site is included in

From an aerial view, the building is composed of a series

surround a central outdoor pool on three sides (south, east and west). The overall dimensions of

the building are 318 feet by 222 feet. The roof is multi

gymnasiums at approximately 39 feet,

approximately 20 feet above the Ground

Level, primarily houses the gymnasiums and recreation rooms. The basement is generally 12’6”

below the Ground Level. The building houses three pools, the main pool is located on the Main

Level and the east and west pools are located on the Ground

Seismic Evaluation of Hearst Memorial Gymnasium – Final Report

BUILDING DESCRIPTION

ESCRIPTION

The Hearst Memorial Gymnasium is a two-story concrete building with a partial basement. The


building is located on a sloping site with grade sloping down towards the west. The building


Building to the northeast. An aerial view of the site is included in Figure S-1.

From an aerial view, the building is composed of a series of rectangular shaped sections that


the building are 318 feet by 222 feet. The roof is multi-level with highest level over the main

ely 39 feet, the intermediate level 29 feet, and the low roof

approximately 20 feet above the Ground Level. The Main Level at 11’6” above the Ground

, primarily houses the gymnasiums and recreation rooms. The basement is generally 12’6”

. The building houses three pools, the main pool is located on the Main

and the east and west pools are located on the Ground Level.

Figure S-1: Site Location

29 October 2018

Page 2

story concrete building with a partial basement. The


wards the west. The building


of rectangular shaped sections that


level with highest level over the main

the intermediate level 29 feet, and the low roof

at 11’6” above the Ground

, primarily houses the gymnasiums and recreation rooms. The basement is generally 12’6”

. The building houses three pools, the main pool is located on the Main



STRUCTURAL SYSTEM

Typical floor and roof structure consists of reinforced concrete slab and beam/girder system

spanning to reinforced concrete columns and walls. Typical foundation is comprised of

reinforced concrete shallow spread footings under the columns and wall pilasters. Concrete slab

diaphragms spanning to reinforced concrete shear walls are the primary lateral force resisting

system of the building. Following is more detail description of various building features:

Exterior and Interior Walls: Reinforced concrete walls constitute the majority of exterior façade

of the building. Concrete walls are typically 12” thick and they are reinforced with 3/8” square

bars in horizontal and vertical directions. Many of the interior concrete walls are discontinuous

below the Main Level and, except for few walls, the remaining interior walls are discontinuous

below the Ground Level. Also, one of the main exterior walls on the west façade of the main

gymnasium is discontinuous below Ground Level.

Columns: Typical column is reinforced with square bars as longitudinal reinforcement and ¼”

diameter ties at various spacing. Ties do not have 135 degree hook at corners. Typical columns

vertical bars are doweled into foundation.

Roof over Main Gymnasium: Roof system is comprised of 3” to 3.5” thick concrete slabs

spanning to beams that in turn span to concrete girders. In the three main gymnasiums, grand

roof girders (approximately 24”x 48” deep) spanning in east-west direction define the boundaries

of series of skylights along the east and west supporting walls. These skylight openings limit the

connection between the roof diaphragm and the supporting walls.

Main and Ground Level: Typical floor is comprised of 4” to 4.5” thick concrete slabs that span

to beams and girders. The main pool, the two courtyards, the two ramps and the light wells

south of main pool create openings in the floor diaphragm. Concrete walls below Ground Level

enclose the courtyard openings.

Ramps: Two ramp structures between the main gymnasiums serve to connect the Main Level to

the Ground Level. Ramp structure is comprised of a 4” thick slab spanning to beams that are

supported by interior columns and edge walls.

Pools: The building houses three pools. Typical pool floor is supported by concrete slab

spanning to interior beams and columns. Slab thickness varies with pool depth. Reinforced

concrete perimeter pool walls extend to the ground and are founded on continuous strip footings.

Top of pool walls are connected to the floor with series of short concrete link beams. The Main

Level slab adjacent the pool is resting on and supported by the link beams, however the link

beams are isolated from floor slab that prevents transfer of shear forces to the pool walls.

Bleachers and Tree Boxes: Concrete bleachers and planter boxes are located on the south, east

and west sides of the main pool. These structures are reinforced concrete components that are

supported by the Main Level beams and columns below.



Filter Rooms: Filter rooms are located underneath the west courtyard, below the Ground Level.

The filter rooms are comprised of reinforced concrete walls that separate the container cells. The

cells are open at top and the walls do not extend up to the Ground Level. The filter room

concrete is severely deteriorated and needs to be replaced.

Nonstructural Ornamentations: Numerous sculptures and decorative motifs adorn the exterior

walls of the building. The method of attachment of these sculptures to the backing concrete

walls is not known. Also, many large urns decorate the outside façade of the building at ground

level. In 1980 the original concrete urns were replaced with fiberglass replicas and anchored to

their bases.

Masonry Walls in the Basement: In 1957, as part of a basement area expansion, reinforced

masonry walls were added to enclose the new basement spaces. Typical masonry partition wall,

supported by continuous spread footing, is constructed tight to the existing columns and soffit of

overhead beams. Masonry walls have minimal attachment only at top to the existing columns.

Alterations to the Building: During the past 50 years, the building has undergone several

alterations/improvement projects. Those with most notable impact to the structure include:

• In 1957, the basement area was partially expanded. The soil under the Ground Level was

excavated without a major impact to the existing footings.

• In 1980, the ornamental concrete urns were replaced with lighter replicas.

• In 1981, a survey of the building was conducted to define the extent of corrosion.

No remediation work was performed.

• In 1996, corrosion repairs were made in some of the spaces immediately adjacent to the

pools



EXISTING MATERIAL PROPERTIES:

A material testing and site investigation program was implemented as part of 2005 Study. The

material testing and site investigation report is included in Structural Appendix 1.

Following is the summary of results:

1. The in-situ concrete compressive strength (f’c) based on cores removed from the

building were in the following range:

• Walls: 1870 psi to 3810 psi, with f’c (average) = 2778 psi

Following values are used in the analysis:

f’c expected = 2800 psi

f’c lower bound = 2150 ps

• Slabs and beams: 2000 psi to 3940 psi, with f’c (average) = 3214 psi.


f’c expected = 3200 psi

f’c lower bound = 2500 psi

2. Concrete unit weight measurement indicate that concrete is normal weight.

3. Reinforcing steel tensile test indicate yield strength in the range of 41,620 psi to

47,490 psi and ultimate strength in the range of 61,000 psi to 70,660 psi.


fy expected = 45.5 ksi

fy lower bound = 43 ksi

4. Chloride Content at 4 locations was tested. The results indicate that the concrete within

0.5 inch of surface contained sufficient chloride to cause corrosion of reinforcing steel.

However, the chloride content dropped significantly beyond the 0.5-inch depth such

that at 1-inch depth the concentration was below the threshold to initiate corrosion. This

indicates that as long as the concrete cover is intact and undamaged, the reinforcing

steel is most likely not corroded.



SEISMIC EVALUATION OF STRUCTURAL ELEMENTS

ASSESSMENT/RETROFIT CRITERIA

As stated in the project RFQ (Project # 18258A), the seismic performance objective is to achieve

UCOP Seismic Performance Level III (GOOD), i.e., Life Safety (S-3) in BSE-1N and Collapse

Prevention (S-5) in BSE-2N per ASCE 41-13. Please refer to Figure S-3.

It is important to note, that due to the project site’s very high seismicity, there are no significant

difference between the seismic performance requirement of California Existing Building Code

for Existing State Owned Buildings (Figure S-2) and UC project objective of meeting UCOP

Seismic Performance Level III (Figure S-3). The main reason is that there are no significant

difference between the BSE-R/BSE-C and the BSE-1N/BSE-2N seismic demands.

According to 2016 California Building Code - Table 1604.5, the Hearst Memorial Gymnasium is

a Risk Category III building. It should be noted that both the California Existing Building Code

(CEBC 2016) and the University of California Seismic Safety Policy (UCOP 2017) require same

seismic performance for risk categories I, II, and III existing buildings.

The 2016 California Historic Building Code provides alternative regulations with the intention of

encouraging “preservation of historic buildings with the objective of preventing partial or total

structural collapse such that the overall risk to life-threatening injury as a result of structural

collapse is low.” Given the nature of the seismic deficiencies of the Hearst Memorial

Gymnasium as identified by this Study, the retrofit recommendations proposed by this Study are

in alignment with the preservation goals and performance objectives of the California Historic

Building Code.

Figure S-2: Table 317.5 – 2016 California Existing Building Code (CBC Part 10)



`

Figure S-3: Expected Seismic Performance Levels

from University of California Seismic Safety Policy



SEISMIC GROUND MOTION SPECTRA

The building site class is assumed to be C, based on the geotechnical information gathered from

the surrounding sites. Please refer to Structural Appendix 2.

The comparison of ASCE 41-13 mapped values and spectra taken from Final Report titled

“2015 Update to the site-specific Seismic Hazard Analyses and Development of Seismic Design

Ground Motions” is shown in Figure S-4. It should be noted that the period of the building is

about 0.3 sec in both directions. The results are based on ASCE 41-13 mapped spectra.

Figure S-2: Hearst Memorial Gymnasium – Site Spectra



ANALYSIS MODELING ASSUMPTIONS

The following modeling assumptions are made:

− Walls between Ground Level and Main Level are modeled inelastically with fiber

elements.

− Walls between roof and Main Level are modeled with elastic frame or shell elements.

These walls are moderately stressed and significant nonlinearity is not expected.

− Walls at the basement level are modeled with elastic shell element, except at locations

where nonlinear behavior is expected such as the wall segments acting as link elements

between selective walls that extend above Ground Level.

− The coupling beams are modeled as frame elements with nonlinear hinges for shear and

flexure.

− The pool walls are modeled as elastic shell elements. The pool is attached to the Main

Level diaphragm through link beams at the perimeter. The link beams are modeled as

frame element with nonlinear shear/flexural hinge and linear axial properties.

− The Main Level diaphragms are modeled as linear elements.

− Roofs are modeled as rigid diaphragm. We do not expect that capturing the nonlinearity

of roof diaphragm will have an impact on our understanding of building behavior. To

verify this assumption, additional analysis was performed with the high roofs modeled as

semi-rigid shell elements.

− Columns under discontinuous shear walls are modeled as elastic frame elements. We

evaluated these columns using the story drift + forces imposed from discontinuous walls

above. Some of the columns were further evaluated with inelastic hinge.

− The initial assumption was not to model foundation flexibility - the wall shell elements

were fixed at base at the foundation locations. Further assessment of structure’s

performance was performed by including the foundation springs.

− The seismic base is assumed to be at the Ground Level and no mass is assigned to the

Ground Level diaphragm.



KEY BUILDING DATA

The seismic weight of the building is calculated as follows:

Table S-1: Building Tributary Seismic Weight Breakdown

Level

Weight

(kips)

Story Height

(ft)

Roof 10,091 16.2 to 23.25

Main Level 10,355 11.5

Ground Level (not included in the model) 10,191 3.5 to 14

Total (with Ground Level) 30,637 max 48.75

Total (without Ground Level) 20,446 27.7 to 34.75

The fundamental periods of the structure are:

T1 = 0.29 sec (in north-south direction)

T2 = 0.27 sec (in east-west direction)

Figure S-3: PERFORM Model



Figure S-4: Grid Lines



ANALYSIS RESULTS

The pushover curve and target displacements for north-south direction are as follows:

Figure S-5: Pushover Curve in North-South Direction

Target displacements in N-S direction:

BSE-1N = 2.39 in

BSE-2N = 4.53 in



The pushover curve and target displacements for east-west direction are as follows:

Figure S-6: Pushover Curve in East-West Direction

Target displacements in E-W direction:

BSE-1N = 2.52 in

BSE-2N = 4.50 in



Results of pushover analysis are summarized in the following graphical outputs of Perform

model.

Figure S-7: Deformed Shape in North-South Direction at BSE-1N Showing the Status of

Wall Shears with Respect to Life-Safety Acceptance Limit (Existing Building)




Wall Shears with Respect to Collapse Prevention Acceptance Limit (Existing Building)




Coupling Beam Shears with respect to Collapse Prevention Acceptance Limit

(Existing Building)



Figure S-10: Deformed Shape at Line 2 in North-South Direction at BSE-2N Showing the

Status of Wall Shears with Respect to Collapse Prevention Acceptance Limit

(Existing Building)



Figure S-11: Deformed Shape at line 6 in North-South Direction at BSE-2N Showing the


(Existing Building)





(Existing Building)





(Existing Building)





(Existing Building)





(Existing Building)




the Shear Deformation in the Beams That Are Connected to the Pool Wall with Respect to

Collapse Prevention Acceptance Limit (Existing Building)



Figure S-17: Deformed Shape in East-West Direction at BSE-1N Showing the Status of

Wall Shears with Respect to Life-Safety Acceptance Limit (Existing Building)



Figure S-18 Deformed Shape in East-West Direction at BSE-2N Showing the Status of

Wall Shears with Respect to Collapse Prevention Acceptance Limit (Existing Building)



Figure S-19: Deformed Shape in East-West Direction at BSE-2N Showing the Status of

Coupling Beam Shears with Respect to Collapse Prevention Acceptance Limit

(Existing Building)



Figure S-20: Deformed Shape in East-West Direction at BSE-2N Showing the Status of the

Shear Deformation in the Beams That Are Connected to the Pool Wall with Respect to

Collapse Prevention Acceptance Limit (Existing Building)



Figure S-21: Seismic Deficiencies at Roof



SUMMARY OF STRUCTURAL DEFICIENCIES

1. Shear walls at many locations above the Main Level do not extend down to the foundation.

Some interior walls at the Ground Level are also discontinuous. This condition causes

unacceptable conditions in various structural components as follows:

1.1. Walls between the Ground and Main Levels experience deformations beyond

acceptable limits as shown on the above figures.

1.2. The deformation demand on columns that support the discontinuous shear walls

exceeds the column capacity as shown in Figures S-12 to S-17. Majority of these

columns are shear controlled.

1.3. Floor diaphragms adjacent to these discontinuous walls are overstressed.

2. Interior gravity columns between Ground Level and Main Level levels are shear controlled

and drift demand exceeds their drift capacity. These columns are typically located between

lines 2 and 13 (see Figure S-6).

3. Roof diaphragms at following locations are inadequate:

3.1. Diaphragms along the east and west edges of the three main gymnasiums are

weakened by the series of skylights. The roof girders spanning in east-west direction

and crossing the skylights will act as the primary component in the load path for

transferring diaphragm forces to the perimeter concrete walls. In the event of a major

earthquake in north-south direction, the roof girders are expected to experience shear

forces exceeding their capacity. Damage to these girders will jeopardize their gravity

load carrying integrity. See Figure S-23.

3.2. Roof diaphragms over the ramps lack sufficient moment capacity leading to excessive

movement due to earthquake in north-south direction.

3.3. Roof diaphragm between the western and central main gymnasiums lack enough shear

capacity to resist earthquake forces in east-west direction.

4. The Main Level diaphragm around the main pool area is overstressed due to the flow of

forces toward the two northern wings (east and west) of the building and the pool walls.

This occurs since the majority of walls in the southern regions of the building are

discontinuous below this level; their shear force is redistributed to other walls of the

building. Below this level the two northern wings and the pool walls are the stiffest

elements that attract the loads.

5. At the Main Level and Ground Level, the floor beams that are connected to the main pool

walls will be damaged due to the large diaphragm force attracted toward the pool walls.

Refer to Figures S-18 and S-22.

6. Majority of perimeter concrete walls along the east and central/south areas of the building

are supported on isolated spread footings. The connection of walls to the footings occurs



only at the columns or pilasters that are within the wall and the remaining portions of walls

over the footings are not extended to the footings. This condition will impose very high

shear demand on the columns and the pilasters that extend to the footings.

7. At the Main Level, the beams under the bleacher structures are overstressed in shear due to

the seismic overturning forces imposed by the bleachers.

8. Several Main Level beams support shear walls that are discontinuous at this level. These

beams will experience shear load exceeding their capacity due to the overturning forces

imposed by these walls. This condition occurs over the western lobby area and three other

similar locations. Failure of these elements poses a serious risk of local loss of the gravity

support for the floor and roof.

9. Spandrel beams at several locations at Main Level experience severe shear overloads. This

condition occurs mainly at walls that are discontinuous below the Main Level.



CONCEPTUAL SEISMIC STRENGTHENING RECOMMENDATIONS

FOR STRUCTURAL ELEMENT

The general approach for the rehabilitation of Hearst Memorial Gymnasium to achieve a GOOD

performance rating is to mitigate / eliminate majority of the discontinuous shear wall conditions

in the building, to locally improve diaphragm deficiencies and to strengthen beams and columns

that support the discontinuous walls that remain in the building.



ANALYSIS OF THE RETROFITTED STRUCTURE

The additional walls that are proposed for the retrofit have been input to the PERFORM 3D

model and analysis results are as follows:

Figure S-22: Pushover Curve in North-South Direction (Retrofitted Building)

Target displacements in N-S direction:

BSE-1N = 1.70 in

BSE-2N = 3.36 in



Figure S-23: Pushover Curve in East-West Direction (Retrofitted Building)

Target displacements in E-W direction:

BSE-1N = 1.78 in

BSE-2N = 3.36 in



ADDITIONAL ANALYSIS IN RESPONSE TO SRC COMMENTS

Rutherford+ Chekene and Fernau & Hartman Architects met with Seismic Review Committee

(SRC) on April 3rd

, 2018 to present findings of this Study. In the meeting, SRC brought up a few

issues that R+C addressed in a memo enclosed in Structural Appendix 3.

As part the response to SRC questions, although nonlinear response history analysis was not in

the scope for this Study, in order to have an approximate check on building response we have run

a nonlinear analysis of the retrofitted building with 7 pairs of scaled ground motions that were

used for Eshleman Hall. It should be noted that the fundamental structural periods for the Hearst

Gym are T1 = 0.3s vs. Eshleman Hall at T1 = 0.8s. This difference in the fundamental periods

between the two buildings will impact the scaling of ground motions for Hearst Gym, but this is

deemed acceptable for this approximate check. The results in general confirmed that retrofit

solution provides sufficient strengthening, reduction of drift.

In addition, additional analysis of high roof over the main gymnasia was conducted to verify

impact of semi rigid diaphragm behavior on the general response of the structure. The results are

summarized in Structural Appendix 3.



STRENGTHENING RECOMMENDATIONS

The recommended strengthening measures are as follows:

1. Mitigation of Discontinuous Walls: Concrete walls are added at strategic locations along

the lines of discontinuous walls. The addition of new walls will also help with diaphragms,

coupling beams and columns overstress condition at many locations. These walls are

connected to floor diaphragm with tie beams. New walls are extended through Ground

Level to the basement/crawl space with new footings provided for all new walls.

1.1. Walls on line 2:

a. New concrete walls are 12” thick with 250 #/CY reinforcement

b. New walls are connected to existing walls with #4 grouted dowels at 24” on

center each way. Walls are connected to existing columns, where they intersect

with 2 rows of #5 grouted dowels at 8” on center.

c. New wall footings are 6’ wide x 4’-6” deep with #250 #/CY reinforcement.

Bottom of footing is at bottom of existing footing.

1.2. Walls on lines 6, 9, 10, 13, and 17:


b. New walls are connected to existing columns or existing walls where they

intersect with 2 rows of #5 grouted dowels at 8” on center.

c. New wall footings: 3’-6” wide x 4’-0” deep continuous strip footings each side of

the (E) footings which are interconnected outside the (E) footing as shown on

foundation plan Sketch-SK4 in Figure S-29. Assume 250 #/CY reinforcement in

footings. Refer to Sketch-SK6 in Figure S-34.

1.3. Walls on lines C&D between lines 6-9 and 10-13:








d. Base of new footings match bottom elevation of (E) footings. (E) footings are

not undermined.

1.4. Walls on lines D between lines 2 & 6 and 13 & 17:










d. Base of new footings match bottom elevation of (E) footings. (E) footings are

not undermined.

1.5. Walls at new stair shaft opening: (see item 8 below).

2. Addition of Collectors below the Main Level and Ground Level Diaphragms: Concrete

collectors are added to distribute diaphragm forces to the concrete walls in the building and

to alleviate local overstress conditions in diaphragms. Refer to plans for locations.

a. Typical collector is 36” wide x 18” deep with 300 #/CY reinforcing.

b. Collectors are connected to existing floor beams with two rows of #5 dowels at

12” on center.

3. Strengthening of Beams Supporting Discontinuous Walls: The beams’ shear capacity is

improved with use of composite fiber. Refer to plans for locations. Assume three layers of

glass fiber FRP on three sides of the beam.

4. Strengthening of Columns Supporting Discontinuous Walls: The columns’ axial load

capacity and ductility is improved with use of composite fiber. Refer to plans for locations.

Assume three layers of glass fiber FRP all around the column.

5. Strengthening of Main Level Diaphragm: The shear capacity of existing concrete slab at

Main Level is enhanced by addition of composite fiber to the underside of the slab. This is

required at local areas adjacent the Main Pool. Refer to Main Level plan Sketch-SK2 in

Figure S-27 for locations. Assume three layers of glass fiber FRP below the floor

slab/beam.

6. Strengthening of Roof Diaphragm and Girders over the Main Gymnasia: Four schemes are

presented for strengthening of roof diaphragms at East and West edges of the three Main

Gymnasia. Refer to Roof plan Sketch-SK1 in Figure S-26.

6.1. Scheme-1 involves adding diagonal steel bracing members within the skylight

openings. Refer to Roof plan Sketch-SK1 in Figure S-26 and Sketch-SK5A in Figure

S-30.

a. Add 8” thick concrete slab below (E) roof slab, as shown on plan, with 200#/CY

rebar. Slab is connected to (E) beams at each side with dowels at 8” on center.

b. Add MC10 channels all around the skylight opening. Channels are connected to

(E) beams and girders with grouted dowels at 8” on center.



c. Add HSS 6x6x1/2 braces as shown on Roof plan Sketch-SK1 in Figure S-26.

6.2. Scheme-2 involves adding infill slab at the end skylight openings. Refer to Roof plan

Sketch-SK1 in Figure S-26 and Sketch-SK5B in Figure S-31.

a. Add 8” thick concrete slab below (E) roof slab and as infill panels, as shown on

plan, with 200#/CY rebar. Slab is connected to (E) beams at each side with

dowels at 8” on center.

6.3. Scheme-3 involves adding concrete edge beams (18” wide x 14” deep) each side of

roof girders within skylight openings. Refer to Roof plan Sketch-SK1 in Figure S-26

and Sketch-SK5C in Figure S-32.

a. Add 8” thick concrete slab below (E) roof slab, as shown on plan, with 200#/CY

rebar. Slab is connected to (E) beams at each side with dowels at 8” on center.

b. Add edge beams with 300#/CY rebar.

6.4. Scheme-4 involves locally strengthening the roof girders within the skylight openings.

Refer to Roof plan Sketch-SK1 in Figure S-26 and Sketch-SK5D in Figure S-33.

a. Add FRP reinforcement all around the roof girder at the skylight opening and on

sides of the girder outside the skylight opening.

b. Reinforce the (E) girders with 4-rows of through dowels 8” on center as shown

on Sketch-SK-5D in Figure S-33.

7. Strengthening of Roof Diaphragm over the South Area between Main Gymnasia: The roof

shear capacity is locally enhanced by adding composite fiber to underside of the slab. Refer

to Roof plan Sketch-SK1 in Figure S-26 for locations. Assume three layers of glass fiber

FRP.

8. The New floor openings for the Fire Stairs East and West: The new stairs require opening

through the Main and Ground Levels. The openings will also require removal of one

column as shown on the plans. Following is the assumed sequence of construction:

a. Add the new roof girders each side of the existing column as shown on Roof plan

Sketch-SK1 in Figure S-26. Assume 12” wide x 30” deep girders. The new

girders will connect to existing walls at each end.

b. Shore the floor and roof beams and girders that are supported by the column that

is to be removed - shore all levels.

c. Construct the new walls with footings.

d. Remove (E) floor to create floor openings.

e. New concrete walls are 10” thick with 250 #/CY reinforcement

f. New footings are 6’ wide x 3’ deep with #250 #/CY reinforcement. Existing

adjacent column footings are to remain.



9. New Foundation Ties for Connection of (E) walls to (E) footings: New concrete foundation

ties are provided to connect the existing walls to existing footings.

a. See foundation plan Sketch-SK4 in Figure S-29 for locations and Sketch-SK7 in

Figure S-35.

b. Assume the new tie extent over the (E) footing as shown on foundation plan

Sketch-SK4 in Figure S-29.

c. Assume 200#/CY reinforcement

d. Tie is connected to (E) wall with two rows of #5 dowels at 12” on center and #6

dowels at 8” on center for connection to (E) footings.

10. Strengthening of Bleachers and Planter Boxes Supporting Members: a) Ground Level

beams below the bleachers and planter boxes are strengthened by adding composite fiber

reinforcing to the three exposed faces of the beams, b) New pilasters are added behind the

bleacher walls to strengthen their east-west direction seismic load transfer capacity, c)

existing steel frames require strength and stiffness enhancement. Refer to Main Level plan

Sketch-SK2 in Figure S-27 for locations.

11. Strengthening of Link Beams Connecting to the Main Pool Walls at Ground and Main

Levels: Beams are strengthened using composite fiber on the three exposed faces of the

beams. Refer to Main and Ground Level plans for locations. Assume three layers of glass

fiber FRP.

12. Mitigation of Corrosion: In 1994, corrosion in selected areas under the Main and Ground

Levels, surrounding the three pools, was repaired. The repair work involved removing the

damaged concrete, cleaning and, if needed, replacing the corroded reinforcement, and

locally adding concrete over the repair area. Based on our walkthrough observations, the

restoration work appears to be effective in stopping the corrosion. We recommend that

similar repair be implemented in the remaining areas where repair was not performed in

1994, most importantly the pool filter room where extensive corrosion of beams and

columns are observed. We also recommend that the enclosed spaces around the pools be

properly ventilated to prevent stagnation of chloride vapor in the building.

13. Nonstructural Deficiencies: The Hearst Gymnasium possesses several instances of applied

and freestanding decorative elements that are non-structural, such as column capitals,

cornices, balustrades, and statuary. A high-level visual inspection of these historically

significant elements suggests that many of them are delaminating from the primary

structure or exhibit corrosion to the extent that they pose hazardous conditions. A

comprehensive survey and strategy of remedying these decorative non-structural elements

was beyond the breath of the seismic study, however, identifying and addressing these

elements is recommended in order to arrest exposure of structural elements such as steel

reinforcement where the applied items have failed, and to mitigate hazards where these

deteriorating items are proximate to the public. This work is recommended to occur in



advance and independent of a future seismic project. The survey should comprise close

visual and physical inspection (sounding/tapping) of the applied and freestanding elements

via a lift, and subsequent documentation of repairs, stabilization strategies, or else

reproduction of character-defining elements.



Figure S-24: Sketch-SK1 - Roof Plan



Figure S-25: Sketch-SK2 - Main Level Plan



Figure S-26: Sketch-SK3 - Ground Level Plan



Figure S-27: Sketch-SK4 - Foundation/Basement Plan



Figure S-28: Sketch-SK5A - High Roof Diaphragm Strengthening – Scheme 1



Figure S-29: Sketch-SK5B - High Roof Diaphragm Strengthening – Scheme 2



Figure S-30: Sketch-SK5C - High Roof Diaphragm Strengthening – Scheme 3



Figure S-31: Sketch-SK5D - High Roof Diaphragm Strengthening – Scheme 4



Figure S-32: Sketch-SK6 - Section at New Interior Wall



Figure S-33: Sketch-SK7 – (N) Concrete Tie between (E) walls and (E) Footing



STRUCTURAL

APPENDIX 1

Material Testing and Site Investigation Report

from 2005

Attachment A.

OF STRUCTURALAPPENDIX 1

ATTACHMENT A



STRUCTURAL

APPENDIX 2

Geotechnical Information Gathered

from Surrounding Sites

SITE CLASS C perR+C GeotechnicalMemo dated9/9/2011

SITE CLASS C perR+C GeotechnicalMemo dated9/9/2011

SOIL CLASS Scper R+CGeotechnicalReport dated5/24/2002

SOIL CLASS Sc per R+CGeotechnical Report dated11/15/2000.Refer to enclosedSubsurface profiles of the site.



STRUCTURAL

APPENDIX 3

Memo to Seismic Review Committee

To: UC Berkeley – Seismic Review Committee

From: Afshar Jalalian/Ayse Celikbas

Date: 07/17/2018

Project: UC Berkeley Hearst Memorial Gymnasium Seismic Study

Job #: 2018-008S

Subject: Responses to Issues discussed during SRC meeting on April 3rd, 2018

Rutherford+ Chekene met with SRC on April 3rd, 2018 to present findings of the seismic evaluation of Hearst Memorial Gymnasium. The meeting minutes are enclosed in Attachment A.

Following are the issues and responses that were brought up by SRC:

Key Point/Action Item 3: If the team elects to do a 3D nonlinear time-history dynamic analysis, it will produce more realistic drift values than calculated from 2D static pushover analysis.

R+C Response: Please note that nonlinear response history analysis was not in the scope for this Study as the University elected for R+C to do 3D nonlinear static pushover analysis. However, in order to have an approximate check on building response we have run a nonlinear analysis of the retrofitted building with 7 pairs of scaled ground motions that were used for Eshleman Hall. It should be noted that the fundamental structural periods for the Hearst Gym are T1 = 0.3s vs. Eshleman Hall at T1 = 0.8s. This difference in the fundamental periods between the two buildings will impact the scaling of ground motions for Hearst Gym, but this is deemed acceptable for this approximate check.

Tables below summarize the peak interstory drift ratios for each motion. The tables also include interstory drift ratios at BSE-2N target displacement for comparison. Please note that for the building site, BSE-2N used for the pushover analysis is similar to BSE-2E (975-year-return-period).

Figure1: Direction of faultdrift

UC Berkeley Seismic Review Committee

of fault-parallel vs. fault normal and locations of reported

07/17/2018 Page 2

fault normal and locations of reported

UC Berkeley 07/17/2018 Seismic Review Committee Page 3

Ground Motion No. 1

Interstory Drift Ratios at BSE-2N Target Displacements

of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-CL-CLYD

Location

Ground to Main Level Main to Roof Level

Location


E-W drift N-S drift E-W drift N-S drift


(%) (%) (%) (%)

(%) (%) (%) (%)

A 1.13% 0.33% 1.20% 0.35%

A 1.40% 1.04% 1.38% 0.88%

C 0.62% 0.25% 0.65% 0.11%

C 1.00% 1.01% 0.79% 0.36%

E 0.60% 0.27% 0.37% 0.33%

E 1.02% 1.01% 0.48% 0.56%

G 0.57% 0.24% 0.29% 0.22%

G 1.01% 0.80% 0.41% 0.41%

I 0.44% 0.22% 0.37% 0.12%

I 0.70% 0.85% 0.52% 0.27%

Acce

lera

tio

n (

g)

Acce

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n (

g)


Ground Motion No. 2


of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-LP-LGPC

Location


Location




(%) (%) (%) (%)

(%) (%) (%) (%)

A 0.47% 0.33% 0.51% 0.35%

A 1.40% 1.04% 1.38% 0.88%

C 0.16% 0.23% 0.14% 0.10%

C 1.00% 1.01% 0.79% 0.36%

E 0.13% 0.29% 0.14% 0.30%

E 1.02% 1.01% 0.48% 0.56%

G 0.13% 0.24% 0.13% 0.22%

G 1.01% 0.80% 0.41% 0.41%

I 0.14% 0.22% 0.15% 0.12%

I 0.70% 0.85% 0.52% 0.27%

Accele

ration (

g)

Accele

ration (

g)


Ground Motion No. 3


of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-MH-Hall

Location


Location




(%) (%) (%) (%)

(%) (%) (%) (%)

A 0.93% 0.27% 1.01% 0.26%

A 1.40% 1.04% 1.38% 0.88%

C 0.32% 0.25% 0.32% 0.11%

C 1.00% 1.01% 0.79% 0.36%

E 0.32% 0.37% 0.19% 0.34%

E 1.02% 1.01% 0.48% 0.56%

G 0.29% 0.24% 0.16% 0.20%

G 1.01% 0.80% 0.41% 0.41%

I 0.22% 0.21% 0.22% 0.14%

I 0.70% 0.85% 0.52% 0.27%

Accele

ration (

g)

Accele

ration (

g)


Ground Motion No. 4


of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-TO-Hino

Location


Location




(%) (%) (%) (%)

(%) (%) (%) (%)

A 0.61% 0.37% 0.62% 0.37%

A 1.40% 1.04% 1.38% 0.88%

C 0.27% 0.30% 0.25% 0.11%

C 1.00% 1.01% 0.79% 0.36%

E 0.26% 0.32% 0.18% 0.34%

E 1.02% 1.01% 0.48% 0.56%

G 0.24% 0.28% 0.14% 0.23%

G 1.01% 0.80% 0.41% 0.41%

I 0.19% 0.27% 0.20% 0.16%

I 0.70% 0.85% 0.52% 0.27%

Acce

lera

tio

n (

g)

Acce

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n (

g)


Ground Motion No. 5


of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-CL-GIL6

Location


Location




(%) (%) (%) (%)

(%) (%) (%) (%)

A 1.44% 0.68% 1.49% 0.64%

A 1.40% 1.04% 1.38% 0.88%

C 0.90% 0.60% 0.88% 0.22%

C 1.00% 1.01% 0.79% 0.36%

E 0.89% 0.72% 0.55% 0.51%

E 1.02% 1.01% 0.48% 0.56%

G 0.82% 0.48% 0.40% 0.32%

G 1.01% 0.80% 0.41% 0.41%

I 0.71% 0.44% 0.55% 0.20%

I 0.70% 0.85% 0.52% 0.27%

Acce

lera

tio

n (

g)

Acce

lera

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n (

g)


Ground Motion No. 6


of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-LP-COR

Location


Location




(%) (%) (%) (%)

(%) (%) (%) (%)

A 0.46% 0.63% 0.54% 0.64%

A 1.40% 1.04% 1.38% 0.88%

C 0.18% 0.57% 0.17% 0.20%

C 1.00% 1.01% 0.79% 0.36%

E 0.17% 0.68% 0.17% 0.54%

E 1.02% 1.01% 0.48% 0.56%

G 0.15% 0.48% 0.14% 0.35%

G 1.01% 0.80% 0.41% 0.41%

I 0.13% 0.42% 0.13% 0.21%

I 0.70% 0.85% 0.52% 0.27%

Acce

lera

tio

n (

g)

Acce

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n (

g)


Ground Motion No. 7


of Pushover Analyses in E-W and N-S Directions Peak Interstory Drift Ratios under Ground Motion 975-MH-ANDD

Location


Location




(%) (%) (%) (%)

(%) (%) (%) (%)

A 0.86% 0.52% 0.91% 0.51%

A 1.40% 1.04% 1.38% 0.88%

C 0.26% 0.46% 0.29% 0.19%

C 1.00% 1.01% 0.79% 0.36%

E 0.25% 0.50% 0.20% 0.43%

E 1.02% 1.01% 0.48% 0.56%

G 0.24% 0.31% 0.18% 0.25%

G 1.01% 0.80% 0.41% 0.41%

I 0.19% 0.32% 0.20% 0.15%

I 0.70% 0.85% 0.52% 0.27%

Acce

lera

tio

n (

g)

Acce

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tio

n (

g)

Key point/Action Item 4: The committee diaphragm as a combination of semi

R+C Response: To investigate the effect of roof diaphragm modeling approach, a comparative study is conducted between models withdiaphragms. Figure 2 illustratesbuilding. Elastic shell and beam elements are used to model the roof diaphragms and girders.

Figure 2: Semi

Figures 3 and 4 show a comparison of the global pushover results between the models with different roof diaphragm models. As can be seen in the figures, the roof diaphragm modeling approach has little impact on the pushover response of the building.

UC Berkeley Seismic Review Committee

The committee suggested the team look at modeling the roof diaphragm as a combination of semi-rigid and rigid to acknowledge the skylights.

To investigate the effect of roof diaphragm modeling approach, a comparative study is conducted between models with semi-rigid and rigid roof

Figure 2 illustrates the semi-rigid roof diaphragms on the south side of the building. Elastic shell and beam elements are used to model the roof diaphragms and

Figure 2: Semi-rigid roof diaphragm model

a comparison of the global pushover results between the models with different roof diaphragm models. As can be seen in the figures, the roof diaphragm modeling approach has little impact on the pushover response of the building.

07/17/2018 Seismic Review Committee Page 10

suggested the team look at modeling the roof rigid and rigid to acknowledge the skylights.

To investigate the effect of roof diaphragm modeling approach, a rigid and rigid roof

rigid roof diaphragms on the south side of the building. Elastic shell and beam elements are used to model the roof diaphragms and

a comparison of the global pushover results between the models with different roof diaphragm models. As can be seen in the figures, the roof diaphragm modeling approach has little impact on the pushover response of the building.


Figure 3: Comparison of pushover response between models with different roof diaphragms (E-W direction)

Figure 4: Comparison of pushover response between models with different roof diaphragms (N-S direction)


Figure 5 shows the N-S peak shear demand on the roof girders across the roof diaphragm openings. The horizontal N-S shear capacity of the roof girder is 147.7 k. As shown in Figure 5, the shear demands on a number of girders exceed the shear capacity; and in addition the shear flow thru the girder creates torsion in the girder which reduces the shear capacity of the girder, hence retrofitting is needed for these members.

Figure 5: N-S horizontal peak shear demands on roof girders (BSE-2N seismic hazard level)

In addition to the above, R+C received the following question from SRC by e-mail: Are the nonlinear static analysis results valid beyond the point of strength degradation? The reason is because rapid strength degradation of one side of the building likely results in an extreme torsion condition that is not likely to be well represented by the static analysis results. The overall conclusions regarding the shortcomings of the building are, however, still likely to be valid.


R+C Response: We agree with SRC and we recommend nonlinear response history analysis to be performed, when this building goes beyond evaluation level into design phase.


ATTACHMENT A

Seismic Review Committee (SRC) Meeting Notes April 3, 2018

OF STRUCTURAL APPENDIX 3

SEISMIC REVIEW COMMITTEE (SRC)

Meeting Notes April 3, 2018

I. SRC members present: Administrative Representation:

Professor Moehle, Chair SRC Technical Advisor: Maryann Phipps Professor Sitar AVC Sally McGarrahan Professor Tobriner Director Shannon Holloway Professor Wilson SRC Coordinator Kathleen Kelly

II. Hearst Memorial Gymnasium Seismic Study, Project 918258

Project Manager: Judy Chess-Physical & Environmental Planning and Nick Morisco – Capital Projects

Design Architect: Fernau + Hartman (Laura Boutelle, Lara Hartman)

Structural Engineer: Rutherford & Chekene (Afshar Jalalian, Ayse Celikbas)

Project Review Phase: Study

The Hearst Memorial Gymnasium is located on Bancroft Way neighboring Barrows Hall to the northwest and the Music Building to the northeast. The structure is a two-story concrete building with a partial basement located on a sloping site with grade sloping down towards the west. The building, constructed in circa 1926, is a historic structure listed on the national register. The building received a Seismic Rating of “Poor” and this study will evaluate and recommend a cost-effective seismic strengthening strategy that will bring the building to a seismic rating of “Good” (III). The project team presented the following:

• Basic project information • Structural Systems • Assessment/Retrofit Criteria • Seismic Ground Motion Spectra • Analysis Modeling Assumptions • Analysis Results • Summary of Deficiencies • Conceptual Retrofit

Key Points/Action Items: 1. The use of code spectra vs. the UCOP seismic policy for level III is appropriate. 2. Using the capped value for the seismic ground motion spectra seemed appropriate. 3. If the team elects to do a 3D nonlinear time-history dynamic analysis, it will produce

more realistic drift values than calculated from the 2D static pushover analysis.

SRC Meeting April 3, 2018 Page 2

4. The committee suggested the team look at modeling the roof diaphragms as a combination of semi-rigid and rigid to acknowledge the skylights.

5. There was consensus about the positive aspect of addressing the torsional issue in the east wing of the building.

6. Site investigation of foundations would appear to be walls without spread footings spanning between columns at the foundation level.

7. Once the study analysis has been completed incorporating the above suggestions, the project team will send their results to SRC Technical Advisor, Maryann Phipps, and review them with Professor Moehle to determine whether the committee needs to review the project again.

III. Structural Seismic Guidelines

Presented by Shannon Holloway, Director of Capital Projects and Maryann Phipps, Technical Advisor

Key Points/Action Required: 1. The committee discussed whether certain building types should require more than

the code. The technical advisor, Maryann Phipps, will develop seismic guidelines for the committee’s review.

2. Professor Sitar noted that guidelines were developed many years ago. SRC Coordinator, Kathleen Kelly, will research the SRC files.

Documents

FORM 1 CERTIFICATE OF SEISMIC PERFORMANCE ......certificate, and I have no ownership interest in the property identified above. My scope of review to support the completion of this