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UTILIZING STEEL PLATE SHEAR WALLS FOR SEISMIC HAZARD

MITIGATION

NASA CIPAIR Summer Internship

By: Agustin Robles, Cham Htun, David Alvarez, and Jasmine Flores

Advisor: Dr. Cheng Chen

Student Advisor: James Enright

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Presentation Outline• Introduction to Steel Plate Shear Walls

• Background information on building and location

• Design calculations• ASCE 7-10 Equivalent Lateral Force Procedure• AISC Code Provisions

• Analysis of structure • SAP2000 lateral force simulations

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Steel Plate Shear Wall Frames• A SPSW frame has three main components:

• Advantages of SPSW:• High plastic energy dissipation• Enhanced stiffness, strength and ductility• Cost efficient

HBE

VB

E

Steel

Plate

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Problem Statement

• Design the optimal member sizes for the:

• Steel plates

• Horizontal boundary elements (HBEs)

• Vertical boundary elements (VBEs)

• Utilize SAP2000 to simulate and evaluate

the structures response to lateral forces.

Design a 3-story office building located at 1300 Market Street, San Francisco, CA 94103. Utilize steel plate shear walls (SPSWs) as the lateral force resisting system.

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Floor psf Height

Floor 3: 95

Floor 2: 90

Floor 1: 92

Total length: 150

Total width: 120

Total floor area: 13,740

Total weight: 3,806

Building Specifications

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Earthquake Probability in the Bay Area

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Equivalent Lateral Force Procedure

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Vertical Distribution of Lateral Forces

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Max Story Drift

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• Determine preliminary sizes for the three main components of the Lateral System• SPSW• HBE• VBE

AISC Seismic Code Provisions

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• The Strip-model was used to approximate SPSW response to lateral forces

• Solving for the angle of inclination, α

• 3rd : α =41.3°• 2nd : α =39.3°• 1st : α =38.3°

AISC Seismic Code Provisions

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• Demand Capacity Ratios (DCR)• Ratio of forces acting on a member with respect to the maximum strength or

capacity of that member• Shear Capacity

• Combined compression and flexure check

AISC Seismic Code Provisions

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• Final member sizes • 2nd floor steel plate redesigned• 3rd and 2nd floor HBE redesigned

• Final design

AISC Seismic Code Provisions

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SAP2000 Analysis of Structure

Building Drift: Inelastic building roof drift

5.35 in

Maximum allowable building drift

10.8 in

Roof drift over building height %

1.2 %

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SAP2000 Analysis of Structure

Moment Axial forces Shear forces

• Figures of forces acting on the structure

Moment Axial forces Shear forces

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SAP2000 Analysis of Structure

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Future Work/ Conclusion• Future/Current Work• Better approximation of the fundamental period

of the structure• Designing the HBEs and VBEs to withstand

some of the shear forces

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Any Questions?