Seismic Hazard Evaluation Report for · PDF fileSeismic Hazard Evaluation Report for Science Building One July 2, 2009 MI0906028.00 . Science Building One ... Using the procedures

Seismic Hazard Evaluation Report for Science Building One July 2, 2009

MI0906028.00

Science Building One

Seismic Hazard Evaluation

Page 2 of 9

goal of ASCE 31 is to identify the “weak links” in a building’s lateral force resisting system that can lead

to significant failure and/or collapse.

The ASCE 31 Tier One procedure is a preliminary screening tool designed to quickly identify potential

seismic deficiencies of the structural lateral-force resisting system and nonstructural building systems.

The Tier One evaluation procedure utilizes a series of checklists for rapid evaluation of the building

while requiring only a minimum level of structural calculations. Our Tier One evaluation is based on a

review of the original building drawings, the information collected during our site visit and the

Degenkolb report.

The Tier One checklists address the structural system, nonstructural elements and geologic and site

hazards. The evaluating engineer addresses each checklist statement and determines whether it is

compliant or non-compliant. Compliant statements identify conditions that are acceptable. Non-

compliant statements identify conditions that are in need of rehabilitation. At this point, the Tier One

deficiencies can be rehabilitated or further evaluation can be performed using the Tier Two procedures.

The Tier Two procedures use structural calculations to address non-compliant Tier One checklist

statements with the intent to demonstrate the Tier One potential seismic deficiencies are actually

satisfactory and need not be rehabilitated. The Tier Two evaluation consists of a building analysis that

only addresses the deficiencies identified by the rapid Tier One evaluation.

If there are still identified potential structural deficiencies at the completion of the Tier Two evaluation,

either the evaluation can be completed and the deficiencies rehabilitated, or a Tier Three evaluation can

be conducted. The Tier Three evaluation consists of a comprehensive, full building detailed seismic

evaluation, typically utilizing non-linear analysis methods.

Our evaluation of Science Building One included a Tier One evaluation in addition to using Tier Two

procedures for evaluating non-compliant Tier One checklist statements.

Performance Objective

Our evaluation of Science Building One is based on a Life-Safety (LS) Performance Level as defined in

ASCE 31. The definition of LS performance level is given in ASCE 31 as follows:

After a design earthquake, Building performance includes damage to both structural and nonstructural

components such that: (a) partial or total structural collapse does not occur, and (b) damage to

nonstructural components is non-life threatening.

In other words this performance objective is meant to ensure that the building will not collapse and that

exit paths from the building will not be blocked, however, the building may be heavily damaged and

may be unable to be occupied after a major earthquake. In addition, the building may not be repairable

after a major earthquake.

Building Description

Science Building One is located on the downtown campus of Portland State University. The building

was originally constructed on 1964 and has remained essentially unaltered since the time of original



Page 3 of 9

construction. The building consists of 6 stories above highest grade level in addition to two basement

levels and a mezzanine level above the First Floor. The total area of Science Building One is

approximately 84,400 square feet. The building is primarily used for classroom, offices and laboratory

facilities.

Science Building One is a concrete shear wall building. Above the Second Floor level, the structural

system consists of steel framed beams and columns that support cast-in-place concrete floor slabs. Below

the Second Floor level, the structural system consists of cast-in-place concrete floor slabs, beams and

columns. The building is rectangular shape with overall dimensions of 176 ft. x 80 ft.

The typical story heights above the Second Floor are 12’-6”, while the First Floor story height is 20’-9”.

The First Floor Mezzanine story height is 8’-6”. The basement levels have story heights of roughly 14 ft.

The perimeter basement walls below ground floor are concrete, supported by strip concrete footings. At

the Basement and Sub-Basement levels, interior concrete columns are supported by individual concrete

spread footings. The Basement level floor consists of structural concrete slabs at locations above the

Sub-Basement level. For areas outside the Sub-Basement footprint, the Basement floor consists of a

concrete slab-on-grade. The entire Sub-Basement floor consists of a concrete slab-on-grade.

The building’s lateral force resisting system consists of a reinforced concrete walls surrounding the

elevator/mechanical and stairwell cores in the building. The core wall thickness ranges from 8” (above

Second Floor level) to 10” (in Basement levels). Several of the core walls have many openings over the

height of the building for doorways and mechanical system penetrations.

Site Description and Seismicity

Science Building One is located on a sloping site with the ground floor at the level of highest exterior

grade. The site slopes from west (high side) to east (low side) with an approximate elevation change of

nearly 10 feet.

Based on our review of the original soils and foundation report, the building is founded on relatively

firm soils. The seismic soil coefficients used for the evaluation of the building are based on the current

classifications from the 2003 National Earthquake Hazards Reduction Program (NEHRP) provisions.

The site soil classification is assumed to be Class D. The amplification factors used to account for the

soil conditions of site are FV equal to 1.7 and FA equal to 1.1.

Science Building One is located in an area of High seismicity according to the categories defined in

ASCE 31. The short period spectral acceleration, SS, using the 2003 NEHRP maps is 0.99g. The long

period spectral acceleration, S1, is 0.35g. There are a number of nearby active faults as listed below.



Page 4 of 9

Closet Sources Magnitude Distance (km) MMI* MMI Damage Description

Portland Hills Fault 6.8 1 IX

Violent shaking.

Considerable damage in

specially designed

structures; well- designed

frame structures thrown

out of plumb; great in

substantial buildings,

with partial collapse.

Cascadia Subduction

Zone 9.0 110 VIII

Severe shaking.

Slight damage in specially

designed structures;

considerable in ordinary

substantial buildings

with partial collapse;

great in poorly built

structures

*MMI’s represent mean values due to shaking only

Table 1: Summary of Nearby Faults

The susceptibility of the site to settlement due to earthquake-induced liquefaction is assumed to be low.

Discussion of Building Deficiencies

Using the procedures of ASCE 31, we have identified a number of deficiencies in the lateral force-

resisting system of this building. The ASCE 31 checklists used to identify the structural and

nonstructural deficiencies are attached as Appendix B.

Structural Deficiencies

• The existing concrete shear wall cores have insufficient strength in the East-West direction of the

building due to the number and location of wall penetrations. Note, in this building direction,

the existing concrete walls only provide roughly 50% of the necessary concrete shear wall needed

to meet the expected earthquake demands for Life-Safety performance.

• The concrete shear walls below the First Floor Mezzanine level are discontinuous and do not extend

into the Basement level below.

• Openings in the floor diaphragm at the shear wall cores at all levels greatly reduce the diaphragm’s

ability to transfer seismic loads to the walls. As such, the existing connection between the floor

diaphragms and the shear wall core may be inadequate for in-plane seismic forces.

• Tall aspect ratios in the core walls greatly reduce the wall’s ability to resist the seismic design forces

expected at the site.



Page 5 of 9

Nonstructural Deficiencies

• Partitions do not appear sufficiently braced to the structure.

• The ceiling system appears to be insufficiently braced to the structure.

• The light fixtures in the ceilings do not appear to be independently supported and/or braced to the

structure.

• Fluorescent light fixtures do not have lens covers.

• The building contents and furnishings are insufficiently braced to the structure to resist

overturning.

• The building mechanical and electrical equipment is insufficiently braced to the structure.

• Piping and duct bracing is insufficient and lacks flexible couplings at joints.

• Elevators have insufficient bracing and/or do not have seismic switches.

Adjacency Hazards

Science Building One is connected to Science Building Two via a pedestrian bridge at the Second Floor

level. Based on our limited site visit observations, it does not appear the bridge support at Science

Building One is properly detailed to accommodate the expected seismic movements. It is possible the

bridge may lose vertical support during strong earthquake shaking and collapse. Although the bridge

does not appear to be a primary egress path for the Second Floor of Science Building One, loss of

vertical support could pose a life-safety hazard due to its proximity to the main building entrance below.

Geologic and Site Hazards

The potential for failure of the foundations and the soil surrounding the site is assumed to be minimal.

Expected Building Performance

Based on the deficiencies described above, Science Building One does not meet the Life-Safety

performance objective of ASCE 31. It has been assigned a deficiency category of Poor/Fair meaning

that the building may not collapse but likely will be heavily damaged in a major earthquake. We

recommend the building be strengthened to a Life-Safety performance level in accordance with ASCE

41, “Seismic Rehabilitation of Existing Buildings”.

Proposed Strengthening Scheme

Based on the identified deficiencies, we have developed a conceptual strengthening scheme for Science

Building One. Conceptual sketches of the structural strengthening scheme are attached in Appendix A

as Figures 1 through 10. These sketches are only intended to show the general layout and minimum

elements of the strengthening scheme and do not constitute a final engineered solution for this

building. The components of the structural strengthening are described below.



Page 6 of 9

Vertical Lateral Elements

• Add reinforced concrete shear walls in East-West direction at all four cores locations. Walls would

extend from the Basement/Sub-basement level to the Roof level (i.e. to underside of 6th Floor). See

Appendix A, Figures 1 through 10 for location, thickness and extent of new concrete shear walls.

Provide epoxy dowels for connection of new concrete walls with existing walls.

Floor Diaphragms

• Add new diaphragm collectors (i.e. drag struts) to deliver earthquake loads from floor slabs to the

shear wall cores. We anticipate the collectors could be added to the underside of existing floor slab

to minimize disruption of floor finishes. See Appendix A, Figures 3 through 9 for location of

diaphragm collectors.

• At Second through Fifth Floor levels, the existing electrical trench reduces the floor slab thickness

from 4½” to 2”. To improve diaphragm capacity, infill existing electrical trench with concrete or

strengthen diaphragm from below. See Appendix A, Figures 5 through 8 for location of trench

infill.

• At First Floor, add new concrete “blocking” beams below selective concrete shear walls which

support the First Floor Mezzanine structure. The existing concrete shear walls are discontinuous

and may produce significant damage to 5” thick concrete floor slab due to overturning actions.

Nonstructural

• Brace all cabinets and other furniture with height-to-depth ratios greater than 3 against overturning.

Note, all cabinets/freezers/refrigerators currently located in Second through Fifth Floor

corridors should be anchored and or strapped to walls to prevent overturning/sliding and

blocking of egress pathways during a major earthquake.

• Brace suspended mechanical equipment to structure.

• Install floor anchorage for all floor mounted mechanical equipment in Basement/Sub-Basement

levels.

• Brace all piping in ceiling spaces and in Basement/Sub-Basement levels.

• Install floor anchorage for electrical cabinets in Sub-Basement.

• Brace all partitions to the structure.

• Install bracing for ceiling systems to structure at 12 feet o.c. each way with independent supports for

ceiling light fixtures.

• Verify the Elevators have sufficient bracing and/or have seismic switches.

Please note that ASCE 31 is a screening tool, and by nature, is quite conservative for a building of this

type and size. For example, the quick shear checks ignore any reinforcing steel in the concrete walls and

the contribution of perpendicular walls to the overall strength of the core. We strongly recommend a

detailed evaluation be performed which will likely show that the performance of this Science



Page 7 of 9

Building One is better than we have concluded and result in a reduction of the necessary

strengthening measures.

Building Impacts of Strengthening Scheme

The conceptual strengthening scheme presented in Appendix A will have impacts on Science Building

One. The four concrete cores in Science Building One currently function as stairwells, elevator shafts

and mechanical shafts. In order to minimize functional impacts and anticipated construction costs, the

locations of new concrete shear walls were selected as shown in Appendix A.

These locations will result in loss of floor area (i.e. due to thickening walls 10” to 12”) for spaces that

appear to currently serve as faculty offices and storage rooms. However, the shear wall locations should

result in minimal disruption to the existing mechanical/electrical systems in the building in addition to

no reduction of egress corridor passageway widths.

In addition, the new concrete shear walls will be visible at the First Floor level exterior (See Appendix A,

Figure 3). The visual impacts to the exterior elevations could be addressed with proper concrete finishes

(i.e. scoring, texturing, stamping, etc.) or covering the walls altogether.

To accomplish this work, we anticipate several interior areas will need to be vacated to allow for

construction activities. We recommend phasing of the construction to minimize tenant and space usage

impacts. However, we suggest an allowance be made in the project budget to address temporary

relocation of affected faculty and building contents.

FEMA Pre-Disaster Mitigation Grant Program

The Federal Emergency Management Agency (FEMA) Hazard Mitigation Assistance programs provide

funding assistance for a number of natural hazard pre-disaster and post-disaster mitigation activities.

We understand Portland State University has successfully applied for and received funding through the

Pre-Disaster Mitigation (PDM) Grant Program for seismic strengthening of other buildings on campus.

Eligibility, and ultimately selection, to receive PDM funding is dependent upon factors that include the

cost effectiveness of the mitigation and feasibility of the project. Historically, PDM projects that have

been funded by FEMA include cost-effective mitigation solutions that provide long-term reduction of

natural hazard risks. Cost effectiveness is demonstrated through developing benefit-cost ratios (BCR)

using the FEMA-validated Benefit Cost Analysis tools. If the calculated BCR is equal to or greater than

1.0, then the proposed mitigation is considered cost effective. Only project applications with a BCR

greater than 1.0 will be considered for PDM funding. In addition, project feasibility is demonstrated by

the development of a comprehensive project program that conceptually addresses the mitigation

implementation solutions.

Based on our understanding of the determined seismic deficiencies, we believe Science Building One is

a good candidate for PDM funding. Our belief is primarily based on the discovery that Science Building

One has only 50% of the necessary concrete shear wall needed to resist earthquake forces in the East-

West building direction. In other words, in the longitudinal building direction, the building is only ½

as strong as it needs to be in order to resist the anticipated earthquake forces.



Page 8 of 9

This is of particular concern due to the proximity and orientation of the adjacent Portland Hills Fault.

Based on the building orientation relative to the Fault, it is likely the strongest ground shaking will

occur in the East-West building direction, which happens to be the weakest. Although we have not

performed a Benefit-Cost Analysis for the building, we anticipate the proposed conceptual mitigation

scheme will result in a BCR greater than 1.0.

Currently, PDM grants will fund up to 75% of the eligible mitigation pre-construction and construction

costs, such as hazard mitigation planning and management costs. For a complete list of eligible and

ineligible project activities, please refer to the FEMA publication, “Hazard Mitigation Assistance Unified

Guidance”, dated June1, 2009. Applications for PDM funding for FY2010 are due on December 4,

2009.

Recommendations

We understand it is the intent of Portland State University to remodel and seismically strengthen

Science Building One. Additionally, we understand that FEMA PDM funding is desirable to help cover

the cost of seismic strengthening. This effort starts with the development of a funding package request

for submission to the Oregon University System.

In order to successfully achieve the project objectives, we propose to develop a Detailed Project Program

(DPP) for Science Building One. We will act as the prime consultant and assemble a DPP team that will

work with Portland State University to prepare the Program. The DPP is essentially a funding document

containing appropriate discipline information, starting with the project program and concluding with a

construction schedule and project cost estimate. Typically the DPP will include the desired phasing,

continued occupancy issues, relocation, hazmat mitigation, ADA, disruption costs and schedule impacts

to properly develop a construction schedule and cost estimate.

As part of the DPP, we recommend a detailed seismic study be performed for Science Building One.

The preliminary seismic evaluation has produced a conceptual strengthening scheme that follows a

conventional and conservative approach to addressing the building seismic deficiencies. However,

based on our understanding of the building, we believe alternate, more cost-effective strengthening

solutions may be possible. Based on our experience with energy dissipating structural systems, we

believe it is possible to add viscous dampers to the building and significantly reduce, or even eliminate,

the need for installing new concrete shear walls. A detailed seismic study would be needed to further

develop the strengthening measures.

At the completion of the DPP, we will work with Portland State University to prepare the PDM

application. As part of this effort, we will perform the Benefit-Cost Analysis and develop the materials

needed to demonstrate the cost-effectiveness and feasibility of the mitigation project. We assume the

previous PDM applications will be available to draw upon in the creation of the PDM application for

Science Building One.

Limitations

The opinions and recommendations presented in this report were developed with the care commonly

used as the state of practice of the profession. No other warranties are included, either expressed or

implied, as to the professional advice included in this report. This report has been prepared for Portland



APPENDIX A: CONCEPTUAL STRENGTHENING SCHEME



APPENDIX B: TIER ONE CHECKLISTS & TIER TWO CALCULATIONS

Chapter 3.0 - Screening Phase (Tier 1)

3 - 70 Seismic Evaluation Standard ASCE 31-02

3.7.9 Basic Structural Checklist For Building Type C2: Concrete Shear Wall

Buildings With Rigid or Stiff Diaphragms

This Basic Structural Checklist shall be completed where required by Table 3-2.

Each of the evaluation statements on this checklist shall be marked compliant (C), non-compliant

(NC), or not applicable (N/A) for a Tier 1 Evaluation. Compliant statements identify issues that are

acceptable according to the criteria of this standard, while non-compliant statements identify issues

that require further investigation. Certain statements may not apply to the buildings being evaluated.

For non-compliant evaluation statements, the design professional may choose to conduct further

investigation using the corresponding Tier 2 evaluation procedure; the section numbers in parentheses

following each evaluation statement correspond to Tier 2 evaluation procedures.

C3.7.9 Basic Structural Checklist For Building Type C2

These buildings have floor and roof framing that consists of cast-in-place concrete slabs, concrete

beams, one-way joists, two-way waffle joists, or flat slabs. Floors are supported on concrete columns

or bearing walls. Lateral forces are resisted by cast-in-place concrete shear walls. In older

construction, shear walls are lightly reinforced, but often extend throughout the building. In more

recent construction, shear walls occur in isolated locations and are more heavily reinforced with

boundary elements and closely spaced ties to provide ductile performance. The diaphragms consist of

concrete slabs and are stiff relative to the walls. Foundations consist of concrete spread footings, mat

foundations, or deep foundations.

Building System

C NC N/A LOAD PATH: The structure shall contain a minimum of one complete load path for Life Safety

and Immediate Occupancy for seismic force effects from any horizontal direction that serves to

transfer the inertial forces from the mass to the foundation. (Tier 2: Sec. 4.3.1.1)

C NC N/A MEZZANINES: Interior mezzanine levels shall be braced independently from the main structure,

or shall be anchored to the lateral-force-resisting elements of the main structure. (Tier 2:

Sec. 4.3.1.3)

C NC N/A WEAK STORY: The strength of the lateral-force-resisting-system in any story shall not be less

than 80% of the strength in an adjacent story, above or below, for Life Safety and Immediate

Occupancy (Tier 2: Sec. 4.3.2.1)

C NC N/A SOFT STORY: The stiffness of the lateral-force-resisting-system in any story shall not be less

than 70% of the stiffness in an adjacent story above or below, or less than 80% of the average

stiffness of the three stories above or below for Life Safety and Immediate Occupancy.

C NC N/A GEOMETRY: There shall be no changes in horizontal dimension of the lateral-force-resisting

system of more than 30% in a story relative to adjacent stories for Life Safety and Immediate

Occupancy, excluding one-story penthouses and mezzanines. (Tier 2: Sec. 4.3.2.3)

C NC N/A VERTICAL DISCONTINUITIES: All vertical elements in the lateral-force-resisting system shall

be continuous to the foundation. (Tier 2: Sec. 4.3.2.4)

C NC N/A MASS: There shall be no change in effective mass more than 50% from one story to the next for

Life Safety and Immediate Occupancy. Light roofs, penthouses and mezzanines need not be

considered. (Tier 2: Sec. 4.3.2.5)


ASCE 31-02 Seismic Evaluation Standard 3 - 71

C NC N/A TORSION: The estimated distance between the story center of mass and the story center of

rigidity shall be less than 20% of the building width in either plan dimension for Life Safety and

Immediate Occupancy. (Tier 2: Sec. 4.3.2.6)

C NC N/A DETERIORATION OF CONCRETE: There shall be no visible deterioration of concrete or

reinforcing steel in any of the vertical- or lateral-force-resisting elements. (Tier 2: Sec. 4.3.3.4)

C NC N/A POST-TENSIONING ANCHORS: There shall be no evidence of corrosion or spalling in the

vicinity of post-tensioning or end fittings. Coil anchors shall not have been used. (Tier 2:

Sec. 4.3.3.5)

C NC N/A CONCRETE WALL CRACKS: All existing diagonal cracks in wall elements shall be less than

1/8" for Life Safety and 1/16" for Immediate Occupancy, shall not be concentrated in one location,

and shall not form an X pattern. (Tier 2: Sec. 4.3.3.9)

Lateral-Force-Resisting System

C NC N/A COMPLETE FRAMES: Steel or concrete frames classified as secondary components shall form a

complete vertical load carrying system. (Tier 2: Sec. 4.4.1.6.1)

C NC N/A REDUNDANCY: The number of lines of shear walls in each principal direction shall be greater

than or equal to 2 for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.1.1)

C NC N/A SHEAR STRESS CHECK: The shear stress in the concrete shear walls, calculated using the Quick

Check procedure of Section 3.5.3.3, shall be less than the greater of 100 psi or 2 cf ' for Life

Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.2.1)

C NC N/A REINFORCING STEEL: The ratio of reinforcing steel area to gross concrete area shall be be not

less than 0.0015 in the vertical direction and 0.0025 in the horizontal direction for Life Safety and

Immediate Occupancy. The spacing of reinforcing steel shall be equal to or less than 18" for Life

Safety and Immediate Occupancy. (Tier 2: Sec. 4.4.2.2.2)

Connections

C NC N/A TRANSFER TO SHEAR WALLS: Diaphragms shall be connected for transfer of loads to the

shear walls for Life Safety and the connections shall be able to develop the lesser of the shear

strength of the walls or diaphragms for Immediate Occupancy. (Tier 2 Sec. 4.6.2.1)

C NC N/A FOUNDATION DOWELS: Wall reinforcement shall be doweled into the foundation for Life

Safety and the dowels shall be able to develop the lesser of the strength of the walls or the uplift

capacity of the foundation for Immediate Occupancy. (Tier 2: Sec. 4.6.3.5)



3.7.9S Supplemental Structural Checklist For Building Type C2: Concrete Shear

Wall Buildings With Rigid or Stiff Diaphragms

This Supplemental Structural Checklist shall be completed where required by Table 3-2. The Basic

Structural Checklist shall be completed prior to completing this Supplemental Structural Checklist.

Lateral-Force-Resisting System

C NC N/A DEFLECTION COMPATIBILITY: Secondary components shall have the shear capacity to

develop the flexural strength of the components for Life Safety and shall meet the requirements of

4.4.1.4.9, 4.4.1.4.10, 4.4.1.4.11, 4.4.1.4.12 and 4.4.1.4.15 for Immediate Occupancy. (Tier 2:

Sec. 4.4.1.6.2)

C NC N/A FLAT SLABS: Flat slabs/plates not part of lateral-force-resisting system shall have continuous

bottom steel through the column joints for Life Safety and Immediate Occupancy. (Tier 2:

Sec. 4.4.1.6.3)

C NC N/A COUPLING BEAMS: The stirrups in coupling beams over means of egress shall be spaced at or

less than d/2 and shall be anchored into the confined core of the beam with hooks of 135° or more

for Life Safety. All coupling beams shall comply with the requirements above and shall have the

capacity in shear to develop the uplift capacity of the adjacent wall for Immediate Occupancy.

(Tier 2: Sec. 4.4.2.2.3)

C NC N/A OVERTURNING: All shear walls shall have aspect ratios less than 4 to 1. Wall piers need not be

considered. This statement shall apply to the Immediate Occupancy Performance Level only. (Tier

2: Sec. 4.4.2.2.4)

C NC N/A CONFINEMENT REINFORCING: For shear walls with aspect ratios greater than 2.0, the

boundary elements shall be confined with spirals or ties with spacing less than 8db. This statement

shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.2.5)

C NC N/A REINFORCING AT OPENINGS: There shall be added trim reinforcement around all wall

openings with a dimension greater than three times the thickness of the wall. This statement shall

apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.2.6)

C NC N/A WALL THICKNESS: Thickness of bearing walls shall not be less than 1/25 the unsupported

height or length, whichever is shorter, nor less than 4". This statement shall apply to the Immediate

Occupancy Performance Level only. (Tier 2: Sec. 4.4.2.2.7)

Diaphragms

C NC N/A DIAPHRAGM CONTINUITY: The diaphragms shall not be composed of split-level floors and

shall not have expansion joints. (Tier 2: Sec. 4.5.1.1)

C NC N/A OPENINGS AT SHEAR WALLS: Diaphragm openings immediately adjacent to the shear walls

shall be less than 25% of the wall length for Life Safety and 15% of the wall length for Immediate

Occupancy. (Tier 2: Sec. 4.5.1.4)

C NC N/A PLAN IRREGULARITIES: There shall be tensile capacity to develop the strength of the

diaphragm at re-entrant corners or other locations of plan irregularities. This statement shall apply

to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.7)

C NC N/A DIAPHRAGM REINFORCEMENT AT OPENINGS: There shall be reinforcing around all

diaphragm openings larger than 50% of the building width in either major plan dimension. This

statement shall apply to the Immediate Occupancy Performance Level only. (Tier 2: Sec. 4.5.1.8)



Connections

C NC N/A UPLIFT AT PILE CAPS: Pile caps shall have top reinforcement and piles shall be anchored to the

pile caps for Life Safety, and the pile cap reinforcement and pile anchorage shall be able to develop

the tensile capacity of the piles for Immediate Occupancy. (Tier 2: Sec. 4.6.3.10)



3.8 Geologic Site Hazards And Foundations Checklist

This Geologic Site Hazards and Foundations Checklist shall be completed where required by Table

3-2.

Each of the evaluation statements on this checklist shall be marked compliant (C), non-compliant

(NC), or not applicable (N/A) for a Tier 1 Evaluation. Compliant statements identify issues that are

acceptable according to the criteria of this standard, while non-compliant statements identify issues

that require further investigation. Certain statements may not apply to the buildings being evaluated.

For non-compliant evaluation statements, the design professional may choose to conduct further

investigation using the corresponding Tier 2 evaluation procedure; the section numbers in parentheses

following each evaluation statement correspond to Tier 2 evaluation procedures.

Geologic Site Hazards

The following statements shall be completed for buildings in levels of high or moderate seismicity.

C NC N/A LIQUEFACTION: Liquefaction susceptible, saturated, loose granular soils that could jeopardize

the building's seismic performance shall not exist in the foundation soils at depths within 50 feet

under the building for Life Safety and Immediate Occupancy. (Tier 2: Sec. 4.7.1.1)

C NC N/A SLOPE FAILURE: The building site shall be sufficiently remote from potential earthquake-

induced slope failures or rockfalls to be unaffected by such failures or shall be capable of

accommodating any predicted movements without failure. (Tier 2: Sec. 4.7.1.2)

C NC N/A SURFACE FAULT RUPTURE: Surface fault rupture and surface displacement at the building site

is not anticipated. (Tier 2: Sec. 4.7.1.3)

Condition of Foundations

The following statement shall be completed for all Tier 1 building evaluations.

C NC N/A FOUNDATION PERFORMANCE: There shall be no evidence of excessive foundation movement

such as settlement or heave that would affect the integrity or strength of the structure. (Tier 2:

Sec. 4.7.2.1)

The following statement shall be completed for buildings in levels of high or moderate seismicity being evaluated to the

Immediate Occupancy Performance Level.

C NC N/A DETERIORATION: There shall not be evidence that foundation elements have deteriorated due to

corrosion, sulfate attack, material breakdown, or other reasons in a manner that would affect the

integrity or strength of the structure. (Tier 2: Sec. 4.7.2.2)

Capacity of Foundations

The following statement shall be completed for all Tier 1 building evaluations.

C NC N/A POLE FOUNDATIONS: Pole foundations shall have a minimum embedment depth of 4 ft for Life

Safety and Immediate Occupancy. (Tier 2: Sec. 4.7.3.1)

The following statements shall be completed for buildings in levels of moderate seismicity being evaluated to the

Immediate Occupancy Performance Level and for buildings in levels of high seismicity.

C NC N/A OVERTURNING: The ratio of the horizontal dimension of the lateral-force-resisting system at the

foundation level to the building height (base/height) shall be greater than 0.6Sa. (Tier 2:

Sec. 4.7.3.2)



C NC N/A TIES BETWEEN FOUNDATION ELEMENTS: The foundation shall have ties adequate to resist

seismic forces where footings, piles, and piers are not restrained by beams, slabs, or soils classified

as Class A, B, or C. (Section 3.5.2.3.1, Tier 2: Sec. 4.7.3.3)

C NC N/A DEEP FOUNDATIONS: Piles and piers shall be capable of transferring the lateral forces between

the structure and the soil. This statement shall apply to the Immediate Occupancy Performance

Level only. (Tier 2: Sec. 4.7.3.4)

C NC N/A SLOPING SITES: The difference in foundation embedment depth from one side of the building to

another shall not exceed one story in height. This statement shall apply to the Immediate

Occupancy Performance Level only. (Tier 2: Sec. 4.7.3.5)

Documents

Seismic Hazard Evaluation Report for · PDF fileSeismic Hazard Evaluation Report for Science Building One July 2, 2009 MI0906028.00 . Science Building One ... Using the procedures