WPM_D09-18046-00_CoSM_Seismic_Tier_1_Evaluation_DRAFT_01-04-2019.pdf

C I T Y O F S A N T A M O N I C A B U I L D I N G A S C E 4 1 - 1 3 T I E R 1

S E I S M I C E V A L U A T I O N

SANTA MONICA, CAL IFORNIA

WALTER P MOORE PROJECT NUMBER D09-18046-00

JANUARY 4, 2019

DRAFT

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January 4, 2019

Sebastian Felbeck

Construction Manager

City of Santa Monica

1437 4th Street #300

Santa Monica, CA 90401

Re: City of Santa Monica Tier 1 Seismic Assessments

WPM Project No: D09-18046-00

Dear Mr. Felbeck:

Walter P. Moore and Associates, Inc. (Walter P Moore) has completed the Tier 1 Seismic

Assessments of 8 buildings in the City of Santa Monica. We understand that the Woodlawn

Cemetery Mausoleum located at 1847 14th Street, Santa Monica, CA was removed from the original list of the buildings (see Walter P Moore Proposal No. 17-2668 dated October 18, 2018). The assessments included review of available existing structural drawings and reports provided by the

Client, visual observations of the interior and exterior of the structures and performing ASCE 41-13

Tier 1 seismic assessment based on the appropriate checklists. The objectives of the assessment were to identify potential structural and nonstructural seismic hazards, and determine if further structural or nonstructural evaluation is required.

The result of our assessment is summarized and listed in the table attached at the end of this letter.

The structural review was limited to an assessment of structural information available through the original structural drawings and limited site observations of visible elements. It is important to note that although these vulnerabilities were identified during the Tier 1 checklist evaluation process, they do not indicate that the structural system is deficient. The intent of the Tier 2 process is to verify that these vulnerabilities apply to the building with additional and more rigorous calculations and analysis of the building performance that utilize the actual building configuration and demands. The Tier 2 methodology can confirm whether these deficiencies exist, and to what extent they should be remediated. High-level retrofit concepts can be developed with the Tier 2 analysis.

If you have any further questions, please let us know.

Sincerely, WALTER P. MOORE AND ASSOCIATES, INC.

Guang Yang, Ph.D., P.E.

Associate

Diagnostics Group

Pawan R Gupta, Ph.D., P.E., S.E., LEED AP

Principal | Managing Director

Diagnostics Group

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Table: Summary of the Tier 1 Seismic Assessments Result

# Building Approx.

Sq. ft.

Non-structural

Hazard

Observed

Tier 2

Assessment

Recommended

A Ocean Park Library at 2601 Main Street, Santa Monica, CA 8,500 Y N

B Memorial Park Community Activity Building at 1401 Olympic Blvd, Santa Monica, CA 6,600 Y N

C Memorial Park Gymnasium Building at 1401 Olympic Blvd, Santa Monica, CA 13,000 Y Y

D Memorial Park PAL Center at 1401 Olympic Blvd, Santa Monica, CA 9,800 Y Y

E 2115 Pico Blvd., Santa Monica, CA 8,000 Y N

F Reed Park Old Youth Office/Storage Building at 1133 7th Street, Santa Monica, CA 500 Y N

G Reed Park Tennis Office/Storage Building at 1133 7th Street Santa Monica, CA 3,200 Y Y

_† Woodlawn Cemetery Mausoleum† at 1847 14th Street, Santa Monica, CA 37,000 -- --

H 1301 4th St., Santa Monica, CA 10,000 Y Y

† The Woodlawn Cemetery Mausoleum located at 1847 14th Street, Santa Monica, CA was removed by the client from the original list of the buildings (see

Walter P Moore Proposal No. 17-2668 dated October 18, 2018).

City of Santa Monica Tier 1 Seismic Assessment

Introductions

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INTRODUCTIONS

Walter P Moore and Associates (WPM) was engaged by the City of Santa Monica to perform an ASCE

41-13 Tier 1 seismic evaluation for eight buildings in Santa Monica, California.

The intent of the evaluation work was to provide an assessment of the buildings seismic vulnerabilities using the ASCE 41-13 Tier 1 screening methodology. Based on our evaluation, this report includes the following:

Evaluation requirements and building information

Summary and discussions of Tier 1 deficiencies

Conclusions and Recommendations for next steps

Tier 1 Checklist and Calculations for Each Building

The Tier 1 reports for each of the building are provided in the following sections and the Tier 1 Checklist and Calculations are shown in the Appendix I and II, respectively. The structural review was limited to an assessment of structural information available through the original structural drawings and limited site observations.

BUILDING PERFORMANCE OBJECTIVES AND TARGET BUILDING PERFORMANCE LEVELS

ASCE 41-13 defines two categories of building performance objectives for new and existing buildings:

Basic Performance Objective for Existing Buildings (BPOE) and Basic Performance Objective Equivalent to New Building Standards (BOPN). This Tier 1 seismic evaluation was performed using the Basic

Performance Objective for Existing Buildings (BPOE).

All the buildings in our assessment were categorized as Risk Category II per the 2016 California Building

Code. Based on the Building Performance Objective BPOE and building Risk Category (II), the Target

Building Performance Levels were selected from ASCE 41-13 Table 2-1 to be Life-Safety (S-3) for structural components and Life-Safety (N-C) for nonstructural components.

The Life-Safety Structural Performance Level (S-3) is defined in ASCE 41-13 as “the post-earthquake damage state in which a structure has damaged components but retains a margin against the onset of partial or total collapse.”

Introductions

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The Life-Safety Nonstructural Performance Level (N-C) is defined in ASCE 41-13 as “the post-earthquake damage state in which nonstructural components may be damaged, but the consequential damage does not pose a life-safety threat.”

The Life-Safety performance level is defined in ASCE41-13 as “the post-earthquake damage state in which a structure has damaged components but retains a margin against the onset of partial or total collapse.” It is important to note that after a large earthquake the buildings may be heavily damaged, unable to be occupied, or even beyond economical repair. Our understanding was that this level of performance, which is also typical for design of new buildings, was acceptable for the buildings.

ASCE 4113 TIER 1 SEISMIC

ASSESSMENT

REPORTS

Ocean Park Library

BUILDING INFORMATION

Building Name Ocean Park Library Building Occupancy Office/Library

Year Built Circa 1915 Floor Area (sq.ft.) 8,500

No. of Levels Above Grade 1 No. of Levels below

Grade

Tier 2 Evaluation Needed N Nonstructural Hazard Y

General Building Description

The Ocean Park Library building was originally designed and built at circa 1915. The original building

(West section) was an un-reinforced masonry building. The original building was retrofitted and a new addition (East section) was built circa 1985 according to the available existing drawings by W. Gayle

Daniel Architect. The building is primarily used as a public library for the City of Santa Monica. The total area of the building is approximately 8,500 square feet. Aerial plan and side views of the building are shown below in Figure A-1 and Figure A-2 with the two sections highlighted. Overview of the building are shown in Photos A-1 through A-3. Typical building plan view is shown in Figure A-3.

Figure A-1 Aerial view – West and East sections

West Section East Section

Figure A-2 Aerial side view (South) – West and East sections

Both East and West sections have 1 story above grade and a basement level. The structural system of the East section consists of wood joist framing supported by interior wood columns and interior/perimeter wood bearing walls, and wood shear walls as the primary lateral-force-resisting system, with wood floor and roof diaphragms. Whereas, the structural system of the West section consists of wood floor joists and roof trusses with brick masonry walls strengthened with an interior reinforced shotcrete overlay as indicated in the 1985 renovation drawings, with wood floor and roof diaphragms.

The roof of the West section consists of wood deck with diagonal steel-rod diaphragm braces (Figure A-

3). The lateral-force-resisting system (wood shear walls and reinforced shotcrete shear overlay walls) are highlighted in red in Figure A-3.

West Section East Section

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Figure A-3 Building plan (lateral system highlighted in red, building outline in blue dashline)

Level of Seismicity and Seismic Hazard Level

The referenced building is located in a High Seismicity area according to definitions in ASCE 41-13 (Table

2-5) and design spectral parameters SDS and SD1 at the BSE-1N level, which is the same as design for a new building utilizing ASCE7. This parameter was only used for determination of site seismicity. The design spectral response acceleration parameters SDS and SD1 were selected using the publicly available USGS Seismic Design Map using ASCE 41-13 parameters. The design short-period spectral acceleration SDS was 1.275 g. The design spectral acceleration at a 1 second (1-s) period SD1 was

0.710 g.

Under the Performance Objective BPOE, the seismic hazard level BSE-1E (for existing buildings) was determined using USGS Seismic Design Map to determine the ASCE 41-13 parameters. The design short-period spectral acceleration SXS at the BSE-1E level was 0.867 g. and the design spectral acceleration at a 1-s period SX1 at the BSE-1E level was 0.480 g.

Site and Soil Properties

No geotechnical report was available at the time of this seismic assessment. Per ASCE/SEI16, the soil class D was assumed for the site. Based on information suggested in the California regulatory map

(Figure A-4), the building is not located within zones of liquefaction, earthquake fault, or earthquake-induced landslide.

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Figure A-4 California regulatory map on geologic hazards

TIER 1 SCREENING

Seismic Checklist Selection

The required checklists for Tier 1 evaluation were selected according to ASCE 41-13 Table 4-7.

Selection of the checklists was based on the level of seismicity and building performance level. The selected checklists were:

Basic Configuration Checklist

Life Safety Checklist for W2: Wood frames, commercial and industrial

Life Safety Checklist for C1/C2A: Concrete shear walls with flexible or stiff diaphragms

Life Safety Nonstructural checklist

Structural Seismic Tier 1 Deficiencies

ASCE41-13 Tier 1 evaluation involves a general check of known vulnerabilities for the building’s lateral system. The checks are high level, and conservative. The identification of a deficiency at this stage only indicates the potential of a condition that requires remediation. Further assessment is required to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The further analysis is carried out in the ASCE41-13 Tier 2 or Tier 3 evaluation.

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Limited site observations of the unconcealed spaces were performed to verify the exposed structural members and connections. No exploratory openings were performed in this seismic assessment

During our review of the existing structural drawing and information gathered during the site visit we found that the existing building does not appear to have structural deficiencies highlighted in the Tier 1 checklists. Refer to Appendix for details of Tier 1 checklist and the calculations.

The following structural Tier 1 checks were listed as “Unknown” in our evaluation due to lack of information in record drawing or limited access during the site visit.

o Wall anchorage: Wall anchorages were included in the existing drawing set but could not be verified visually during the visit as those are concealed and not visually accessible.

o Wood sills/sill bolts: The connections from the wood sills to the foundation in the east structure were included in the existing drawing set but could not be verified visually during the visit as those are concealed and not visually accessible.

o Foundation dowels: The shear wall reinforcement doweled in the foundation in the west structure is not present in the existing drawing set. It cannot be verified visually during the visit as those are concealed and not visually accessible.

o Cross ties: The cross ties in the east structure are not present in the existing drawing set. It cannot be verified visually during the visit as those are concealed and not visually accessible.

Nonstructural Deficiencies

The following nonstructural deficiencies were identified in the Life Safety Nonstructural Checklist.

Fall-Prone Contents: Fall prone contents are not braced or restrained and can fall over during a seismic event (Photo A-4). Equipment or stored items weighing more than 20lb whose center of mass is more than 4ft above the floor level should be properly braced or otherwise restrained.

The following nonstructural Tier 1 checks were listed as “Unknown” in our evaluation due to limited access during site visit.

Glazing Panel Connections: Cladding panels should be anchored out-of-plane with a minimum of 4 connections per wall panel for a building in high seismic zone. Due to lack of original building as-built drawings and limited access during the site visit, this criteria could not be verified.

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Elevator Retainer Guards: The elevator sheaves and drums should have cable retainer guards.

Due to limited access during site visit, this criteria could not be verified.

Elevator Retainer Plates: A retainer plate should be present at the top and the bottom of the car and the counterweight. Due to limited access during site visit, this criteria could not be verified.

OBSERVATION PHOTOS

Photo A-1 : Overview of the building – West façade of the building

Photo A-2: Overview of the building – North and East façade of the building

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CONCLUSIONS & RECOMMENDATIONS

The Ocean Park Library building in the City of Santa Monica is located in a highly seismic region, was not constructed within a benchmark era for its building type, but was seismically retrofitted circa 1985 and does not appear to have seismic structural deficiencies identified by the ASCE41-13 Tier 1 checklists.

However, we recommend that the following non-structural seismic hazards be addressed:

Brace or anchor the tall narrow contents in the storage room

Photo A-3: Overview of the building – South and West façade of the building

Photo A-4: Fall-prone storage content at top of the shelf in the storage room

Memorial Park Community Activity Building

Building Name Memorial Park Community

Activity Building

Occupancy Office/Recreational

Year Built Circa 1975 Floor Area (sq.ft.) 6,600

No. of Levels Above Grade 1 No. of Levels below

Grade

Tier 2 Evaluation Needed N Nonstructural Hazard Y

General Building Description

The Memorial Park Community Activity building was originally designed and built circa 1975 according to the available existing drawings by Stanley Borbals, Architect, AIA & Associates dated February 10, 1975.

The building is primarily used as a public Community Activity Center for the City of Santa Monica. The building is a reinforced masonry building with a total area of approximately 6,600 square feet. Aerial plan and side views of the building are shown below in Figure B-1 and Figure B-2 with the building highlighted. Overview of the buildings are shown in Photos B-1 through B3. Typical building plan view is shown in Figure B-3.

Figure B-1 Aerial view

Figure B-2 Aerial side view (West elevation)

The building has 1 story above grade. The structure is comprised of reinforced brick masonry walls as the primary lateral-force-resisting system, with wood joist and wood roof diaphragm. The lateral-force-ressisting system (reinforced masonry shear walls) are highlighted in red in Figure B-3.

Figure B-3 Roof framing plan (lateral system highlighted in red, building outline in blue dashline)

The referenced building is located in a High Seismicity area according to definitions in ASCE 41-13 (Table

2-5) and design spectral parameters SDS and SD1 at the BSE-1N level, which is the same as design for a new building utilizing ASCE7. This parameter was only used for determination of site seismicity. The design spectral response acceleration parameters SDS and SD1 were selected using the publicly available USGS Seismic Design Map using ASCE 41-13 parameters. The design short-period spectral acceleration SDS was 1.351 g. The design spectral acceleration at a 1 second (1-s) period SD1 was

0.751 g.

Under the Basic Performance Objective for Existing (BPOE) building, the seismic hazard level BSE-1E (for existing buildings) was determined using USGS Seismic Design Map to determine the ASCE 41-13 parameters. The design short-period spectral acceleration SXS at the BSE-1E level was 0.881 g. The design spectral acceleration at a 1-s period SX1 at the BSE-1E level was 0. 489 g.

Site and Soil Properties

No geotechnical report was available at the time of this assessment. Per ASCE/SEI16, the soil class D was assumed for the site. Based on information suggested in the California regulatory map (Figure B-4), the building is not located within zones of liquefaction, earthquake fault, or earthquake-induced landslide.

Figure B-4 California regulatory map on geologic hazards

Seismic Checklist Selection

The required checklists for Tier 1 evaluation were selected according to ASCE 41-13 Table 4-7.

Selection of the checklists was based on the level of seismicity and building performance level. The selected checklists were:

Basic Configuration Checklist

Life Safety Checklist for RM1/RM2: Reinforced masonry bearing walls with flexible or stiff diaphragms

Life Safety Nonstructural checklist

Structural Seismic Tier 1 Deficiencies

ASCE41-13 Tier 1 evaluation involves a general check of known vulnerabilities for the building’s lateral system. The checks are high level, and conservative. The identification of a deficiency at this stage only indicates the potential of a condition that requires remediation. Further assessment is required to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The further analysis is carried out in the ASCE41-13 Tier 2 or Tier 3 evaluation.

Limited site observations of the unconcealed spaces were performed to verify the exposed structural members and connections. No exploratory openings were performed in this seismic assessment.

During our review of the existing structural drawing and information gathered during the site visit we found that the existing building has structural deficiencies identified in the Basic Configuration, Reinforced

Masonry Walls Tier 1 checklists as below:

Wood Ledger: The connections between the roof diaphragm and the reinforced masonry shear walls in the transverse direction induce cross-grain bending in the wood ledger. Wood members in general have little resistance to load applied perpendicular to grain. Failure in cross-grain bending results in ledger breaking and separation between diaphragm and walls.

The following structural Tier 1 checks were listed as “Unknown” in our evaluation due to limited access during site visit.

Stiffness of Wall Anchors: the masonry wall anchors were concealed and not visually accessible during the site visit. It could not be verified if the anchors were installed taut and stiff enough to limit relative movement between masonry walls to wood diaphragm elements. Based on the age of the structure, and our review of the structural drawings, this is likely not a significant concern.

However, further evaluation on these anchorages is recommended to verify the condition of the anchors. The evaluation would require opening or removal of selected ceiling or wall finishes.

Nonstructural Deficiencies

The following nonstructural deficiencies were identified in the Life Safety Nonstructural Checklist.

Fall-prone contents: Fall prone contents are not braced or restrained and can fall over during a seismic event (Photo B-4). Equipment or stored items weighing more than 20lb whose center of mass is more than 4ft above the floor level should be properly braced or otherwise restrained.

Photo B-1 : Overview– East side of the building

Photo B-2: Overview– West side of the building

The Memorial Park Community Activity Building is located in a highly seismic region, was not constructed within a benchmark era for its building type. Based on our review of available existing structural drawings provided by the City of Santa Monica and limited site observations of the unconcealed spaces, it appeared that the existing building has structural deficiencies at the roof diaphragm connection to the reinforced masonry shear walls. Our recommendation is:

Mitigation with elements or connections needed to provide wall anchorage without inducing cross-grain bending is recommended to achieve the selected Performance Level. The connections between the roof diaphragm and the reinforced masonry shear walls in the transverse direction induce cross-grain bending in the wood ledger, which can result in ledger breaking and separation between diaphragm and walls during seismic event.

Photo B-3: Overview– South side of the building

Photo B-4: Fall-prone storage content at the top of a shelf in the storage room

Several nonstructural components were also identified as noncompliant with the Tier 1 methodology.

Mitigation is needed to achieve desired performance level of these non-structural components.

Brace or anchor the tall narrow contents in the storage room

Memorial Park Gymnasium Building

Building Name Memorial Park Gymnasium Occupancy Recreational/Office

Year Built Circa 1970 Floor Area (sq.ft.) 13,000

No. of Levels Above Grade 1 No. of Levels below

Grade

Tier 2 Evaluation Needed Y Nonstructural Hazard Y

General Building Description

The Memorial Park Gymnasium Building was originally designed and built circa 1970 according to the available as-built drawings provided by the City of Santa Monica. The building has three sections: the main building, the North wing and the East addition. The main building is used as a basketball court for the City of Santa Monica. The North wing and East addition are used as office and storage room, respectively. The total area of the building is approximately 13,000 square feet. Aerial plan and side views of the building are shown below in Figure C-1 and Figure C-2 with three sections highlighted. Overview of the building are shown in Photos C-1 through C-3. Typical building plan view is shown in Figure C-3.

Figure C-1 Aerial view

Main Building

East Addition

North wing

Community

Activity Center

PAL Building

Figure C-2 Aerial view - East side

The main building was approx. 122 feet by 92 feet with a building height of approx. 29’-0”. As shown in

Figure C-3, the East, West, and South perimeter walls were reinforced concrete frames with reinforced infill masonry shear walls for the upper portion and reinforced concrete moment frames for the lower portion (Photos C-1 and C-2). While the North perimeter wall is a reinforced concrete frame with reinforced infill masonry shear wall (Photo C-3). The lateral-force-resisting system (reinforced masonry walls, moment frames) are highlighted in red in Figure C-3.

The roof of the main building is comprised of wood sheathing supported by wood joists at 16” on center

(spanning East-West direction) and wood beams at approximately 8’-0” on center (spanning in the

North-South direction), which are supported by tapered steel girders spaced at approximately 20’-0” on center (spanning in East-West direction), as shown in Photo C-4.

The North wing is a one-story L-shaped reinforced masonry office building with a roof height of approx.

11’-6”. The roof of the North wing consists of wood roof joists and wood deck sheathing. The East addition was built circa 2002 based on the record drawings by Genik Daly, dated August 19, 2002. The

East addition is one-story storage room comprised of composite structural panels (so called

“metalstudcrete” panels with metal stud framing and infilled concrete) as perimeter shear wall, steel columns and joists, and metal deck.

Main Building

North wing

East Addition

Figure C-3 Building plan (lateral system highlighted in red, building outline in blue dashline)

The referenced building is located in a High Seismicity area according to definitions in ASCE 41-13 (Table

2-5) and design spectral parameters SDS and SD1 at the BSE-1N level, which is the same as design for a new building utilizing ASCE7. This parameter was only used for determination of site seismicity. The design spectral response acceleration parameters SDS and SD1 were selected using the publicly available USGS Seismic Design Map using ASCE 41-13 parameters. The design short-period spectral

NORTH

WING

acceleration SDS was 1.351 g. The design spectral acceleration at a 1 second (1-s) period SD1 was

0.751 g.

Under the Performance Objective BPOE, the seismic hazard level BSE-1E (for existing buildings) was determined using USGS Seismic Design Map to determine the ASCE 41-13 parameters. The design short-period spectral acceleration SXS at the BSE-1E level was 0.881 g. The design spectral acceleration at a 1-s period SX1 at the BSE-1E level was 0.489 g.

Site and Soil Properties

No geotechnical report was available at the time of this seismic assessment. Per ASCE/SEI16, the soil class D was assumed for the site. Based on information suggested in the California regulatory map

(Figure C-4), the building is not located within zones of liquefaction, earthquake fault, or earthquake-induced landslide.

Figure C-4 California regulatory map on geologic hazards

The required checklists for Tier 1 evaluation were selected according to ASCE 41-13 Table 4-7.

Selection of the checklists was based on the level of seismicity and building performance level. The selected checklists were:

Basic Configuration Checklist

Life Safety Checklist for C1: Concrete moment frames

Life Safety Checklist for C3: Concrete frames with infill masonry shear walls

Life Safety Checklist for RM1: Reinforced masonry bearing walls

Life Safety Nonstructural checklist

It shall be noted that the East addition was built at 2003, which is later than benchmark building year of similar type. Tier 1 seismic assessment need not be performed for buildings designed and constructed or evaluated in accordance with the benchmark provisions per ASCE 41-13. However, an evaluation of nonstructural elements in accordance was still performed.

Structural Seismic Tier 1 Deficiencies

ASCE41-13 Tier 1 evaluation involves a general check of known vulnerabilities for the building’s lateral system. The checks are high level, and conservative. The identification of a deficiency at this stage only indicates the potential of a condition that requires remediation. Further assessment is required to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The further analysis is carried out in the ASCE41-13 Tier 2 or Tier 3 evaluation.

The following structural deficiencies were identified in the Basic Configuration, Wood Frame, and

Concrete Wall Tier 1 checklists.

Adjacent Building: The gymnasium building is adjacent to the PAL Center. The distance between the two buildings is smaller than the requirement per ASCE 41-13 Tier 1 Checklist. Adjacent structures without sufficient clearance between them may experience damage due to pounding of the buildings during an earthquake. Pounding can alter the seismic response of both buildings and introduce additional inertial forces.

Torsion: The rigidity of the concrete frame with infilled masonry shear walls for the North perimeter is much greater than that of the moment frames for the South perimeter. Therefore, the distance between the center of rigidity and the center of mass is more than 20% of the building width required by Tier 1 Checklist.

Wood Ledger: The connections between the roof diaphragm and the reinforced masonry shear walls induce cross-grain bending in the wood ledger. Wood members in general have little resistance to load applied perpendicular to grain. Failure in cross-grain bending results in ledger breaking and separation between diaphragm and walls.

Cross Ties: The record drawing does not show any continuous cross ties along the joist spanning in North-South direction.

Redundancy: In the South perimeter, only two columns (one bay) of moment frame exist, which gives no redundancy along this side. There shall be at least two bays along each side of the building per Tier 1 Checklist.

Column Shear Stress Check: The shear stress calculated using the Quick Check Procedure in

Tier 1 Checklist is greater than the required stress.

No Shear Failure: The shear capacity of the columns does not appear to be able to develop the moment capacity. Shear failure is brittle and sudden compared to flexural failure and can cause more hazards during a seismic event. This check is to ensure the failure mode is ductile.

Column-Bar Splices: The rebar lap length of 36 inches is smaller than 35 times the rebar diameter required by the Tier 1 Checklist. Inadequate lap length may lead to connection failure and potential risk of collapse during seismic event.

Beam-Bar Splices: Lap splice exists within a quarter of the span length of the joints, which does not satisfy the requirement in Tier 1 Checklist. Lap splice shall be avoided at areas close to the joints, where large deformation is anticipated during seismic event.

Nonstructural Deficiencies

The following nonstructural deficiencies were identified in the Life Safety Nonstructural Checklist.

Fall-Prone Contents: Fall prone contents are not braced or restrained and can fall over during a seismic event (Photo C-5). Equipment or stored items weighing more than 20lb whose center of mass is more than 4ft above the floor level should be properly braced or otherwise restrained.

Tall Narrow Contents: Tall, narrow contents (e.g. storage cabinets) appeared to be not always anchored to the floor and/or wall and can fall over during a seismic event (Photo C-6). Contents more than 6ft high with a height-to-depth or height-to-width ratio greater than 3-to-1 are recommended to be properly anchored to the structure per Tier 1 Checklist requirements.

Photo C-1: Overview of the building – South face of the building

Photo C-2: Overview of the building – West

Concrete moment frame Reinforced masonry shear wall

Interior masonry wall

Adjacent PAL Building

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Photo C-3: Overview of the building – North

Photo C-4: Interior view of main building

Photo C-5: Fall-prone storage contents located at the East addition

Infill masonry walls

Concrete frame

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The Memorial Park Gymnasium building in the City of Santa Monica is located in a highly seismic region, was not constructed within a benchmark era for its building type. Several structural deficiencies were observed and the recommended actions includes:

Perform Tier 2 assessment to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The following items shall be evaluated:

o Torsional Effect: The rigidity of the concrete frame with infilled masonry shear walls for the North perimeter is much greater than that of the moment frames for the south perimeter.

o Lack of Redundancy: In the South perimeter, only two columns (one bay) of moment frame exist, which gives no redundancy along this side.

o Adjacent Building: The gymnasium building is adjacent to the PAL Center. The distance between the two buildings is smaller than the requirement per ASCE 41-13 Tier 1

Checklist. Pounding effect shall be further investigated.

o Wood Ledger: The connections between the roof diaphragm and the reinforced masonry shear walls induce cross-grain bending in the wood ledger, which may result in ledger breaking and separation between diaphragm and walls. Exploratory opening is suggested to verify the existing condition of the wood ledger.

o Cross Ties: No continuous cross ties were observed along the North-South direction.

Exploratory opening is suggested to verify the existing condition of the cross ties.

Photo C-6: Lockers located in main building storage room are tall, narrow, and appeared to be not properly anchored

D09.18046.00|04 January 2019 10 o Further investigation of the moment frames shall be performed in Tier 2 assessment includes the following items:

Column Shear Stress Check: The shear stress calculated using the Quick

Check Procedure in Tier 1 Checklist is greater than the required stress.

No Shear Failure: The shear capacity of the columns does not appear to be able to develop the moment capacity.

Column-Bar Splices: The rebar lap length of 36 inches is smaller than 35 times the rebar diameter required by the Tier 1 Checklist.

Beam-Bar Splices: Lap splice exists within a quarter of the span length of the joints, which does not satisfy the requirement in Tier 1 Checklist.

It is important to note that although this vulnerability was identified during the Tier 1 checklist evaluation process, they do not indicate that the structural system is deficient. The intent of the Tier 2 process is to verify that this vulnerability applies to the building with additional and more rigorous calculations and analysis of the building performance that utilize the actual building configuration and demands. The Tier 2 methodology can confirm whether this deficiency exists, and to what extent it should be remediated.

High-level retrofit concepts can be developed with the Tier 2 analysis.

Several nonstructural components were also identified as noncompliant with the Tier 1 methodology.

Mitigation is needed to achieve desired performance level of these non-structural components.

Mitigate nonstructural seismic hazards identified in Tier 1 assessment o Brace or anchor the tall narrow contents in the storage room

Memorial Park PAL Center

Building Name Memorial Park PAL Center Occupancy Office/Recreational

Year Built Circa 1992 Floor Area (sq.ft.) 9,800

No. of Levels Above Grade 1 No. of Levels below

Grade

Tier 2 Evaluation Needed Y Nonstructural Hazard Y

General Building Description

The Memorial Park PAL Center building was originally designed and built circa 1992. The West section of the building is a wood shear wall building and the East section is a tilt-up structure according to the available existing drawings by Louis J. Liets Architect dated at July 30, 1992. The building is primarily used as an activity center for the City of Santa Monica. The total area of the building is approximately

9,800 square feet. Aerial plan and side views of the building are shown below in Figure D-1 and Figure

D-2 with the two sections highlighted. Typical building plan view is shown in Figure D-3.

Figure D-1 Aerial view – West and East sections

Figure D-2 Aerial side view (south) – West and East sections

Both East and West sections have 1 story above grade. The structure of East section consists of concrete tiltup shear walls as the primary lateral-force-resisting system, with steel open web roof joists and lite-crete over metal roof deck. The West structure is comprised of wood shear walls with steel studs as the primary lateral-force-resisting system, steel open web joists framing and lite-crete over metal roof deck. The lateral-force-resisting system (wood shear walls and reinforced concrete tilt-up walls) are highlighted in red in Figure D-3.

Figure D-3 Building Plan (wood shear walls and tilt-up concrete shear walls are highlighted in red and blue, respectively)

West Section

The referenced building is located in a High Seismicity area according to definitions in ASCE 41-13 (Table

2-5) and design spectral parameters SDS and SD1 at the BSE-1N level, which is the same as design for a new building utilizing ASCE7. This parameter was only used for determination of site seismicity. The design spectral response acceleration parameters SDS and SD1 were selected using the publicly available USGS Seismic Design Map using ASCE 41-13 parameters. The design short-period spectral acceleration SDS was 1.351 g. The design spectral acceleration at a 1 second (1-s) period SD1 was

0.751 g.

Under the Performance Objective for Existing (BPOE) building, the seismic hazard level BSE-1E (for existing buildings) was determined using USGS Seismic Design Map to determine the ASCE 41-13 parameters. The design short-period spectral acceleration SXS at the BSE-1E level was 0.881g. The design spectral acceleration at a 1-s period SX1 at the BSE-1E level was 0.489 g.

Site and Soil Properties

No geotechnical report was available at the time of this assessment. Per ASCE/SEI16, the soil class D was assumed for the site. Based on information suggested in the California regulatory map (Fig. D-4), the building is not located within zones of liquefaction, earthquake fault, or earthquake-induced landslide.

Figure D-4 California regulatory map on geologic hazards

The required checklists for Tier 1 evaluation were selected according to ASCE 41-13 Table 4-7.

Selection of the checklists was based on the level of seismicity and building performance level. The selected checklists were:

Basic Configuration Checklist

Life Safety Checklist for W2: Wood frames, commercial and industrial

Life Safety Checklist for PC1/PC1A: Precast or tilt-up concrete shear walls with flexible or stiff diaphragms

Life Safety Nonstructural checklist

Structural Seismic Tier 1 Deficiencies

ASCE41-13 Tier 1 evaluation involves a general check of known vulnerabilities for the building’s lateral system. The checks are high level, and conservative. The identification of a deficiency at this stage only indicates the potential of a condition that requires remediation. Further assessment is required to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The further analysis is carried out in the ASCE41-13 Tier 2 or Tier 3 evaluation.

Limited site observations of the unconcealed spaces were performed to verify the exposed structural members and connections. No exploratory openings were performed in this seismic assessment.

During our review of the existing structural drawing and information gathered during the site visit we found that the existing building has structural deficiencies identified in the Basic Configuration, Reinforced

Masonry Walls Tier 1 checklists as below:

Load Path: In the West section, it appeared that wood shear walls only exist at the internal of the building. Collectors shall be provided to drag diaphragm load and transfer it to the internal shear walls. The building does not appear to have collectors along the East-West direction. Moreover, it appeared that the original design intends to use perimeter walls as shear walls, however, due to the window openings along the perimeter wall, the efficiency of lateral resistance provided by these perimeter walls are questionable.

Adjacent Building: The East section of the building is adjacent to the gymnasium building. The distance between the two buildings is smaller than the requirement per ASCE 41-13 Tier 1

Checklist. Adjacent structures without sufficient clearance between them may experience damage due to pounding of the buildings during an earthquake. Pounding can alter the seismic response of both buildings and introduce additional inertial forces.

The following structural Tier 1 checks were listed as “Unknown” in our evaluation due to limited access during site visit.

Precast wall panels: The precast wall panel appeared to not be properly connected to the foundation in the East structure per the existing drawing set. This connection is important for proper load transfer from the diaphragm all the way to the foundation. The connection cannot be verified visually during the visit as those are concealed and not visually accessible.

Nonstructural Deficiencies

The following nonstructural deficiencies were identified in the Position Retention Nonstructural Checklist.

Tall Narrow Contents: Tall, narrow contents (e.g. storage cabinets) appeared to be not always anchored to the floor and/or wall and can fall over during a seismic event (Photo D-4). Contents more than 6 ft high with a height-to-depth or height-to-width ratio greater than 3-to-1 are recommended to be properly anchored to the structure per Tier 1 checklist requirements.

Fall-Prone Contents: Fall prone contents are not braced or restrained and can fall over during a seismic event (Photo D-5). Equipment or stored items weighing more than 20lb whose center of

Photo D-1 : Overview of the building – South façade of West section

Photo D-2: Overview of the building – South façade of East section

Photo D-3: Overview of the building – North façade Adjacent Gym

Building

East Section

Photo D-4: Bookshelf in the Room 109 (Dance and Aerobics room) is not properly anchored

Photo D-5: Fall-prone storage contents found in Room 108 (Arts and Crafts room)

The Memorial Park PAL building in the City of Santa Monica is located in a highly seismic region, was not constructed within a benchmark era for its building type, and has seismic deficiencies identified by the

ASCE41-13 Tier 1 checklists. Several structural deficiencies were observed and the recommended actions includes:

Perform Tier 2 assessment to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The following items shall be evaluated:

o Load Path: Collectors appear to be missing along the East-West direction. Also, the efficiency of lateral resistance provided by these perimeter walls is questionable due to the openings along the walls. Further investigation shall be performed on the collectors and perimeter shear walls in Tier 2 assessment.

o Adjacent Building: Adjacent structures without sufficient clearance between them may experience damage due to pounding of the buildings during an earthquake. Further investigation needs to be performed to evaluate the effect of pounding in Tier 2 assessment.

It is important to note that although this vulnerability was identified during the Tier 1 checklist evaluation process, they do not indicate that the structural system is deficient. Further assessment is required to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The further analysis is carried out in the ASCE41-13 Tier 2 or Tier 3 evaluation.

Several nonstructural components were also identified as noncompliant with the Tier 1 methodology.

Mitigation is needed to achieve desired performance level of these non-structural components.

Brace or anchor the tall narrow contents in the Room 109

Brace or anchor the fall-prone storage contents in the Room 108

2115 Pico Blvd Building

Building Name 2115 Pico Blvd Building Occupancy Office

Year Built Circa 1965 Floor Area (sq.ft.) 8,000

No. of Levels Above Grade 1 No. of Levels below

Grade

Tier 2 Evaluation Needed N Nonstructural Hazard Y

General Building Description

The 2115 Pico Blvd building is a tilt-up building originally designed and built circa 1965. The building was renovated in 2003 according to the available existing drawings by KoningEizenberg dated August 25, 2003. The building is primarily used as public gymnasium and offices for the City of Santa Monica. The total area of the building is approximately 8,000 square feet. Aerial plan and overall views of the building are shown below in Figure E-1, and Photos E-1 through E-3, respectively. Typical building plan view is shown in Figure E-2.

Figure E-1 Aerial view – 2115 Pico Blvd Building

The original building is comprised of tilt up concrete shear walls as the primary lateral-force-resisting system, with wood posts, joists framing and roof deck. During the 2003 renovation, the tilt up wall on the

East side of the building was replaced by reinforced masonry shear walls per record drawings. The lateral-force-resisting system (tilt up shear walls and reinforced masonry shear walls) are highlighted in red in Figure E-2.

Figure E-2 Building plan (Tilt up concrete walls and reinforced masonry walls highlighted in red and blue, respectively)

Level of Seismicity and Seismic Hazard Level

The referenced building is located in a High Seismicity area according to definitions in ASCE 41-13 (Table

2-5) and design spectral parameters SDS and SD1 at the BSE-1N level, which is the same as design for a new building utilizing ASCE7. This parameter was only used for determination of site seismicity. The design spectral response acceleration parameters SDS and SD1 were selected using the publicly available USGS Seismic Design Map using ASCE 41-13 parameters. The design short-period spectral acceleration SDS was 1.348 g. The design spectral acceleration at a 1 second (1-s) period SD1 was

0.748 g.

Under the Basic Performance Objective of Existing buildings (BPOE), the seismic hazard level BSE-1E

(for existing buildings) was determined using USGS Seismic Design Map to determine the ASCE 41-13 parameters. The design short-period spectral acceleration SXS at the BSE-1E level was 0.883 g. The design spectral acceleration at a 1-s period SX1 at the BSE-1E level was 0.491 g.

Site and Soil Properties

No geotechnical report was available at the time of this assessment. Per ASCE/SEI16, the soil class D was assumed for the site. Based on information suggested in the California regulatory map (Figure E-3), the building is not located within zones of liquefaction, earthquake fault, or earthquake-induced landslide.

Figure E-3 California regulatory map on geologic hazards

Seismic Checklist Selection

The required checklists for Tier 1 evaluation were selected according to ASCE 41-13 Table 4-7.

Selection of the checklists was based on the level of seismicity and building performance level. The selected checklists were:

Basic Configuration Checklist

Life Safety Checklist for PC1: Precast or Tilt-up Concrete Shear Walls with Flexible

Diaphragms

Life Safety Checklist for RM1: Reinforced Masonry Bearing Walls with Flexible diaphragms

Life Safety Nonstructural checklist

Structural Seismic Tier 1 Deficiencies

ASCE41-13 Tier 1 evaluation involves a general check of known vulnerabilities for the building’s lateral system. The checks are high level, and conservative. The identification of a deficiency at this stage only indicates the potential of a condition that requires remediation. Further assessment is required to determine the impact of the deficiency on the performance of this specific building, and the extent of retrofit. The further analysis is carried out in the ASCE41-13 Tier 2 or Tier 3 evaluation.

Limited site observations of the unconcealed spaces were performed to verify the exposed structural members and connections. No exploratory openings were performed in this seismic assessment

During our review of the existing structural drawing and information gathered during the site visit we found that the existing building does not appear to have structural deficiencies highlighted in the Tier 1 checklists. Refer to Appendix for details of Tier 1 checklist and the calculations.

The following structural Tier 1 checks were listed as “Unknown” in our evaluation due to limited access during site visit.

o Reinforcing Steel: The reinforcing steel in the tilt-up walls is unknown. The ratio of reinforcing steel area to gross concrete area shall be not less than 0.0012 in the vertical direction and

0.0020 in the horizontal direction per Tier 1 Checklist requirement.

o Straight Sheathing: The sheathing panel sizes are unknown. All straight sheathed diaphragms shall have an aspect ratio of less than 2-to-1 in the direction being considered per Tier 1

Checklist requirement.

o Connections to Foundation: Connections are unknown between precast walls/reinforced masonry walls and the existing foundations.

Nonstructural Deficiencies

The following nonstructural deficiencies were identified in the Life Safety Nonstructural Checklist.

Appendages: Slender exterior lighting equipment’s were cantilevered approximately 3.5 feet outwards on the South face of the building at the roof level (Photo E-4). The connection of the lighting equipment appeared to be inadequate in resisting the seismic load.

Fall-Prone Contents: Fall prone contents are not braced or restrained and can fall over during a seismic event (Photo E-5). Equipment or stored items weighing more than 20lb whose center of

The following nonstructural Tier 1 checks were listed as “Unknown” in our evaluation due to limited access during site visit.

Canopies: Connections of the Canopies to the building are unknown. Canopies at building exits shall be anchored to the structure at a spacing no greater than 6 feet for Life Safety in High

Seismicity area per Tier 1 Checklist.

Photo E-1 : Overview of the building – North

Photo E-2: Overview of the building – South

Photo E-3: Overview of the building – East side of the building (CMU Walls)

Photo E-4: Slender exterior lighting on the

South face of the building

Photo E-5: Fall-prone storage content at one shelf in the building

The 2115 Pico Blvd Building is located in a highly seismic region, was not constructed within a benchmark era for its building type, and appeared to have no seismic deficiencies by the ASCE 41-13

Tier 1 Checklists. It shall be noted that our assessment is mainly based on review of available existing structural drawings provided by the City of Santa Monica. Limited site observations of the unconcealed spaces were also performed to verify the exposed structural members. No exploratory openings was performed in this assessment.

Several nonstructural components were also identified as noncompliant with the Tier 1 methodology.

Mitigation is needed to achieve desired performance level of these non-structural components.

Mitigate nonstructural seismic hazards identified in Tier 1 assessment o Repair the connection for the exterior lighting at the South face…