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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

Presentation Outline • Introduction to Steel Plate Shear Walls • Background information on building and location

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• Design calculations • ASCE 7-10 Equivalent Lateral Force Procedure • AISC Code Provisions • Analysis of structure • SAP2000 lateral force simulations

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

HBE Steel Plate 3

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

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Problem Statement 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.

• 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.

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Building Specifications

Floor Floor 3: Floor 2: Floor 1: psf

95 90 92

Height

12 12 12

Total length: Total width: Total floor area: Total weight:

150 120 13,740 3,806 𝑓𝑡 𝑓𝑡 𝑓𝑡 2 𝑘𝑖𝑝𝑠

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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AISC Seismic Code Provisions • Determine preliminary sizes for the three main components of the Lateral System • SPSW • HBE • VBE

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AISC Seismic Code Provisions • The Strip-model was used to approximate SPSW response to lateral forces

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• • • • Solving for the angle of inclination, α 3 2 1 rd nd st : α =41.3° : α =39.3° : α =38.3°

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AISC Seismic Code Provisions • 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 • Final member sizes • 2 nd floor steel plate redesigned • 3 rd and 2 nd floor HBE redesigned • Final design

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SAP2000 Analysis of Structure

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Building Drift: Inelastic building roof drift Maximum allowable building drift Roof drift over building height % 5.35 in 10.8 in 1.2

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SAP2000 Analysis of Structure • Figures of forces acting on the structure

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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?

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