Report

1 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 2 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 3 Steel Plate Shear Wall Frames • A SPSW frame has three main components: VBE HBE Steel Plate • Advantages of SPSW: • High plastic energy dissipation • Enhanced stiffness, strength and ductility • Cost efficient 4 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. 5 Building Specifications Floor psf Height Floor 3: 95 12 Floor 2: 90 12 Floor 1: 92 12 Total length: 150 Total width: 120 Total floor area: 13,740 2 Total weight: 3,806 6 Earthquake Probability in the Bay Area 7 Equivalent Lateral Force Procedure 8 Vertical Distribution of Lateral Forces 9 Max Story Drift 10 AISC Seismic Code Provisions • Determine preliminary sizes for the three main components of the Lateral System • SPSW • HBE • VBE 11 AISC Seismic Code Provisions • 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° 12 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 13 AISC Seismic Code Provisions • Final member sizes • 2nd floor steel plate redesigned • 3rd and 2nd floor HBE redesigned • Final design 14 SAP2000 Analysis of Structure Building Drift: Inelastic building 5.35 in roof drift Maximum allowable 10.8 in building drift Roof drift over 1.2 % building height % 15 SAP2000 Analysis of Structure • Figures of forces acting on the structure Moment Moment Axial forces Shear Shear forces Axial forces forces 16 SAP2000 Analysis of Structure 17 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 18 Any Questions?