Structural models Christine Goulet, Presenter Curt B. Haselton – Assistant Professor, CSU Chico Abbie B. Liel - PhD Candidate, Stanford University Farzin Zareian - Assistant Professor, University of California Irvine

Structural model selection Criteria Represent modern constructions Building-code compliance, newly designed structures Provide useful preliminary guidance Limit the rate of collapse VS older non-ductile structures The models are also calibrated to allow collapse Cover different heights/number of stories 4, 12 and 20 Evaluate different structural systems Special moment resisting frame and shear wall Use different platforms OpenSees and Drain

The selected buildings Stories Type Compliance T1 (s) Platform A 4 Modern special moment frame 2003 IBC 0.97 OpenSees B 12 2003 IBC, ASCE7-02, ACI 318-02 2.01 C 20 2.63 D Modern (ductile) planar shear wall None specifically, but consistent with modern planar wall design 1.20 Drain

Building A, B and C: Structural Modeling Perimeter 2D frame Plastic Hinge Model Overall objective is to develop and implement generalized-hinge type elements for modeling P-M-V interaction in reinforced concrete frame members. Emphasis is on models that are sufficiently robust to model collapse performance, but also practical and efficient to implement and use. Joints with panel shear springs Image: Paul Cordova of Stanford University

Building A: 4-story RC SMF Based on engineering drawings 4-story perimeter frame, 30’ bay widths, designed to have strength and stiffness expected from a practitioner design Design Code: 2003 IBC Structural Design and Model by: Curt Haselton of CSU Chico

Building A: 4-story RC SMF Design base shear 9.2% of weight T1 – T4 (sec) = 0.97, 0.35, 0.18, 0.12 Yielding: Roof drift = 0.5%, interstory drift = 0.7% Roof drift at 20% strength loss = 5.2% 0.05 0.10 1 2 3 4 Floor Number Interstory Drift Ratios Static Overstrength = 2.3

Building A: 4-story RC SMF Nonlinear Dynamic Failure Modes

Marge d’erreur (2% sur 50 ans) Source: Curt Haselton

Building B: 12-story RC SMF Design details reviewed by practicing engineers 12-story special moment resisting (SMF) perimeter frame, 20’ bay widthsDesign Codes: 2003 International Building Code, ASCE7-02, ACI 318-02 Structural design and model by [Design ID #1013]: Curt B. Haselton, PhD, PE, Assistant Professor of Civil Engineering, California State University, Chico. Brian S. Dean, MS student, Stanford University. 120’x120’ plan

Building B: 12-story RC SMF Design base shear of 4.4% of weight Static overstrength = 1.7 T1 – T4 (sec) = 2.01, 0.68, 0.39, 0.27 Static Overstrength = 1.7

Building B: 12-story RC SMF Nonlinear Dynamic Failure Modes (a) 73% of collapses (b) 25% of collapses (c) 2% of collapses

Building C: 20-story RC SMF Design details reviewed by practicing engineers 20-story special moment resisting (SMF) perimeter frame, 20’ bay widths Design Codes: 2003 International Building Code, ASCE7-02, ACI 318-02 Structural design and model by [Design ID #1020]: Curt B. Haselton, PhD, PE, Assistant Professor of Civil Engineering, California State University, Chico. Brian S. Dean, MS student, Stanford University. 120’x120’ plan

Building C: 20-story RC SMF Design base shear of 4.4% of weight Static overstrength = 1.6 T1 – T4 (sec) = 2.63, 0.85, 0.46, 0.32 Static Overstrength = 1.6

Building D: 12-story Shear Wall 12-story planar shear wall, with uniform cross-section over the building height. Design Codes: None specifically, since this is a generic model, but this model is representative with a modern building. Structural Design and Model by: Farzin Zareian, PhD, Assistant Professor of Civil Engineering, University of California Irvine. 12 X 12’ = 144’

Building D: 12-story Shear Wall Yield base shear of 16.7% of weight T1 – T4 (sec) = 1.20, 0.19, 0.068, 0.035

The selected buildings Stories Type Compliance T1 (s) Platform A 4 Modern special moment frame 2003 IBC 0.97 OpenSees B 12 2003 IBC, ASCE7-02, ACI 318-02 2.01 C 20 2.63 D Modern (ductile) planar shear wall None specifically, but consistent with modern planar wall design 1.20 Drain

Building 1: Structural Modeling Basic Strength Deterioration Post-Capping Strength Deterioration Model developed by Ibarra, Medina, and Krawinkler Image: Lehman (2003)

Building 1: Structural Modeling Model calibrated to 255 flexurally dominated test from PEER Structural Performance Database (Berry and Eberhard) Model Parameters to be Predicted: Strength (easiest) Initial stiffness Post-yield stiffness Plastic rotation capacity Negative post-cap slope Cyclic deterioration rate f’c is concrete strength in MPa v is axial load ratio [P/Agf’c] ρsh is the lateral confinement ratio asl – bond-slip – 0 or 1