Acceptance Criteria and Modeling RC Core Wall Buildings

Acceptance Criteria and Modeling RC Core Wall Buildings John Wallace, Professor Kristijan Kolozvari, Assistant Professor Amin Safdari, PhD Candidate Saman Abdullah, PhD Candidate CMMI-1446423 NSF SAVI Wall Institute (Wallace) CMMI-1538866 NSF Resilient Tall Buildings (Burton + Wallace) Charles Pankow Foundation: RGA #06-17 (Wallace + Kolozvari) CMMI-1563577 NSF Tall Buildings Design Framework (Kolozvari) PEER Annual Meeting Berkeley, CA January 18-19, 2018 Acceptance Criteria and Modeling Approaches for RC Core Wall Buildings Coupling Beams Structural Walls LATBSDC 2017 Updates Modeling Updates 2 Wallace, Kolozvari, Safdari, Abdullah 1

COUPLING BEAMS 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 3 Coupling Beam Stiffness PEER TBI (2010) and LATB (2014) Recommendations RC coupling beams: EI eff = 0.20I g Based mainly on tests by Naish et al (2013), Naish (2010) Diagonally- and conventionally-reinforced 2.4 (l n /h) 3.33 Update addresses: Expand range: 1.0 (l n /h) 5.0 Upper-bound: EI eff 0.30I g Diagonally- vs conventionally-reinforced RC coupling beams with encased structural steel sections Background 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 4 Wallace, Kolozvari, Safdari, Abdullah 2

Coupling Beam Stiffness (Diagonal) Test database (56) BRI 12-Story (8) Naish (7) Hwang (4) Lequesne (3) Fortney (2) Canbolat (1) Dogus (1) Zhou (1) Binney (3) Barney (2) Tassios (2) Kwan & Zhou (1) Galano & Vignoli (7) Kimura (10) Adebar (1) Penelis (1) Sanobe (2) Stiffness Adjustments: Naish et al (2013) Slab Contribution, Axial Restraint 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 5 Coupling Beam Stiffness (Diagonal) Test database (56) BRI 12-Story (8) Naish (7) Hwang (4) Lequesne (3) Fortney (2) Canbolat (1) Dogus (1) Zhou (1) Binney (3) Barney (2) Tassios (2) Kwan & Zhou (1) Galano & Vignoli (7) Kimura (10) Adebar (1) Penelis (1) Sanobe (2) Stiffness Adjustments: Naish et al (2013) Scale (slip springs) [rebar pullout from wall boundary] 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 6 Wallace, Kolozvari, Safdari, Abdullah 3

Coupling Beam Stiffness (Diagonal) Test database (56) BRI 12-Story (8) Naish (7) Hwang (4) Lequesne (3) Fortney (2) Canbolat (1) Dogus (1) Zhou (1) Binney (3) Barney (2) Tassios (2) Kwan & Zhou (1) Galano & Vignoli (7) Kimura (10) Adebar (1) Penelis (1) Sanobe (2) Stiffness Adjustments: V/Vncode Slab, axial restraint, scale (slip) 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 PT Slab RC Slab No Slab ASCE 41-06 0 2 4 6 8 10 12 14 Rotation [% drift] 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 7 Coupling Beam Stiffness (Diagonal) Test database (56) BRI 12-Story (8) Naish (7) Hwang (4) Lequesne (3) Fortney (2) Canbolat (1) Dogus (1) Zhou (1) Binney (3) Barney (2) Tassios (2) Kwan & Zhou (1) Galano & Vignoli (7) Kimura (10) Adebar (1) Penelis (1) Sanobe (2) 0.3 0.2 0.1 0 Test Data -0.04+0.085(l n /h) EI eff = 0.07(l n /h) EI EI 0.07l h eff g n GA 0.4E A 1 2 3 4 l n /h c 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 8 Wallace, Kolozvari, Safdari, Abdullah 4

Coupling Beam Stiffness (Conventional) Test database (36) Hwang (4) Naish (1) Zhu (1) Zhou (2) Brena (4) Kwan & Zhao (9) Galano & Vignoli (4) Bristowe (4) Barney (3) Binnay (2) Tassios (2) Paulay (12) [outliers] 0.5 0.4 0.3 0.2 0.1 0 Test Data -0.03+0.06(l n/h) EI eff = 0.07(l n /h) 0.3 EI EI 0.07 l h 0.3 GA 0.4E A 1 2 3 4 5 l n /h 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 9 eff g n c Coupling Beam Stiffness (Conventional) Steel-Reinforced RC (Motter et al, ASCE, 2016) Embedment Length V n & M n Detailing Stiffness EI l h E I eff 0.06 n s trans PEER TBI 2.0 Recommendation EI 0.07l h E I eff n s trans GA 0.4E A c 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 10 Wallace, Kolozvari, Safdari, Abdullah 5

STRUCTURAL WALLS 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 11 Wall Shear Strength Wallace, LATB, May 2013; Kim (2016) V u V n, e V V u u MCE u test 1 V = 0.5 1.57 V 0.3 ne, ACI = 1.0 Low Probability of Collapse Compute the Final Probability of Collapse Under MCE R Ground Motion 7% P[C MCE R ] Probability Density Function Value 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Demand Capacity 0 0 1 2 3 4 5 6 Demand and Capacity (Normalized to Mean Demand of 1.0) 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 12 Wallace, Kolozvari, Safdari, Abdullah 6

Wall Shear Strength Shear vs Flexure-Shear Failure Limit nonlinear deformations Reliable test overstrength 5 0.0025 l 0.8l s y w w 0. 01 If mean ε s 0.01, then: = 1.0 Otherwise: = 0.75 Memorialized: Hamburger et al, May 2013 5 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 13 Wall Shear Acceptance Criterion PEER TBI (2016) 1.0I V 1.3I V V BV e ns e EQ ns s n V 1.5A 2 f f 15 A f V ne cv ce t ye cv ce ne n 1. 5 B 0.9V V 1. 35 ne B 0.75(1.35) = 1.0 s V n LATBSDC 2005-2017 1.0I V 1.5I V V V e ns e EQ ns ' ' f 1.17 f & f 1.3f f 1.14 V ye y ce c c ne 1.15 V n 1.15V 1.0I V 1.5I V V e ns e EQ ns 1.0I V 1.3I V V e ns e EQ ns ne s BV n n LATBSDC 2017 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 14 Wallace, Kolozvari, Safdari, Abdullah 7

Wall Shear Strength: LATB (2017) UCLA RCwalls Database 1000+ tests (51 tests) h w l w 2.0 h p p w l total p p y l s total w c Vne/Vn V V ne n s 0.01 min 1.5 0.02 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 15 STRUCTURAL WALLS: PANEL ZONES 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 16 Wallace, Kolozvari, Safdari, Abdullah 8

Tall Buildings: Modeling + Acceptance January 19, 2018 Wall Panel Zones Earthquake Damage (Chile 2010) Vn Acv 3 f c' s,min f y 0.25 f c' Vu 0.75 Vn 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 17 LATB 2017 GUIDELINES 1.0IeVns 1.3Ie VEQ Vns s BVn Values for: B 0.9Vne Vn and s 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA Wallace, Kolozvari, Safdari, Abdullah 18 9

LATB 2017: Draft s and B-values Component Seismic Action Classification s B Flexure Ordinary 0.9 1.0 Below Grade Perimeter Walls Shear Ordinary 0.9 1.0 Below Grade Non-Perimeter / Non-Core Walls Shear Ordinary 0.9 1.0 Core Walls Above and Below Grade and All Shear Critical 0.75 1.35 Above Grade Walls Flexure Ordinary 0.9 1.0 Diaphragm with Major Shear Transfer Shear Critical 0.75 1.35 Axial (includes Ordinary 0.9 1.0 Typical (non-transfer slab) Diaphragm Forces chord forces) (excludes collectors and shear transfer to Flexure Ordinary 0.9 1.0 vertical element) Shear Ordinary 0.9 1.0 Compression Critical 0.65 1.0 Drag (Collector) Members Tension Critical 0.9 1.0 Bearing Critical 0.65 1.0 Vertical Element-to-Diaphragm Connection Shear Transfer Critical 0.75 1.0 (Shear Friction) Axial Critical 0.65 1.0 Gravity Columns and Special Moment Frames Shear Critical 0.75 1.0 (Beams, Columns, Beam-Column joints) excluding, Intentional Outrigger Columns, & Flexure (in Axial Columns Supporting Discontinuous Vertical Flexure Ordinary 0.9 1.0 Elements) Combinations) Axial Critical 0.65 1.0 Shear Critical 0.75 1.0 Intentional Outrigger Columns & Columns Supporting Discontinuous Vertical Elements* Flexure (in Axial Flexure Ordinary 0.9 1.0 Combinations) Flexure Critical 0.9 1.0 Transfer Girders* Shear Critical 0.75 1.0 Flexure Ordinary 0.9 1.0 Foundations Shear (w/av) Critical 0.75 1.35 Shear (w/o Av) Critical 0.75 1.00 Compression Critical 0.65 1.0 Tension Ordinary 0.9 1.0 Foundation Piles (Structural Capacity) Flexure Ordinary 0.9 1.0 Shear Critical 0.75 1.0 Diaphragms with major shear transfer Flexure Ordinary 0.9 1.0 Shear Critical 0.75 1.35 Mat Foundations Shear Critical 0.75 1.0 Flexure Ordinary 0.9 1.0 Shear (w/a v) Critical 0.75 1.35 Shear (w/o A v) Critical 0.75 1.00 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 19 LATB 2017: Foundation Shear ACI 318-14 Simplified ACI 318-14 Detailed Beams w/av S D Beams w/o Av V c 1.0 f ' c 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 20 Wallace, Kolozvari, Safdari, Abdullah 10

MODELING UPDATES 2018 PEER ANNUAL MEETING - BERKELEY, CALIFORNIA 21 Nonlinear Modeling of RC Core Walls Current Approach, Issues, and Research Needs Fiber-based models Perform 3D, no updates OpenSees, developing Issues Uncoupled P-M & V Plane sections Research Needs Biaxial loading Strength loss BE, Confined Concrete Web, Unconfined Concrete Fiber section BE, Confined Concrete System-level behavior Uniaxial Material Models Perform 3D Model Isometric view Wallace, Kolozvari, Safdari, Abdullah 11

Recent OpenSees Implementations 2D Macroscopic Models for RC Walls MVLEM P-M fiber section V - shear spring P-M and V uncoupled SFI_MVLEM P-M-V coupled NL shear behavior Computationally more demanding Kolozvari et al. (2018), Computers and Structures Journal (link) 23 Current OpenSees Developments 3D Macroscopic Models 4-node 3D models with 24 DOFs Suitable for modeling of RC core walls Computationally efficient and easy to use Publicly available by the end of 2018 OpenSees Model 4NodeMVLEM3D 4NodeSFI_MVLEM3D 24 Wallace, Kolozvari, Safdari, Abdullah 12

Current OpenSees Developments 3D Finite Element Models In-plane behavior Bi-linear interpolation 2D RC constitutive model Out-of-plane behavior Elastic plate Layered shell Single-layer FE model Multi-layer FE model Constitutive material model Fixed-Strut-Angle-Model 25 Current OpenSees Developments 3D Finite Element Model - FSAM Fixed-strut angle approach (Orakcal et al., 2012) Uniaxial Materials Shear aggregate interlock Strains Stresses Reinforcement dowel action 26 Wallace, Kolozvari, Safdari, Abdullah 13

3D Finite Element Model Experimental Validation 40 specimens 8 experimental programs Range of parameters h w /l w = 1.50-3.13 Spec. No. Spec. ID Author Crosssection h/lw fybe (MPa) b,v (%) w,v (%) w,h (%) M/(Vlw) P/(Agf ' c) Vmax/(Acv f ' c) 1 RW1 Thomsen and Wallace R 3.00 434 1.15 0.33 0.33 3.13 0.11 2.6 BR 2 RW2 Thomsen and Wallace R 3.00 434 1.15 0.33 0.33 3.13 0.09 2.7 CB 3 SP1 Tran and Wallace R 2.00 472 3.23 0.27 0.27 2.00 0.10 3.8 DT 4 SP2 Tran and Wallace R 2.00 477 7.11 0.61 0.61 2.00 0.10 6.3 CB 5 SP3 Tran and Wallace R 1.50 472 3.23 0.32 0.32 1.50 0.10 5.1 CB 6 SP4 Tran and Wallace R 1.50 477 6.06 0.73 0.73 1.50 0.10 7.8 DC 7 SP5 Tran and Wallace R 1.50 477 6.06 0.61 0.61 1.50 0.03 6.4 DC 8 R1 Oesterle et al R 2.34 512 1.47 0.25 0.31 2.40 0.00 1.1 BR 9 R2 Oesterle et al R 2.34 450 4.00 0.25 0.31 2.40 0.00 2.1 BR 10 B1 Oesterle et al B 2.34 449.5 1.11 0.29 0.31 2.40 0.00 2.4 R 11 B2 Oesterle et al B 2.34 410.2 3.67 0.29 0.63 2.40 0.00 6.0 BR 12 B3 Oesterle et al B 2.34 437.8 1.11 0.29 0.31 2.40 0.00 2.6 BR 13 B4 Oesterle et al B 2.34 450.2 1.11 0.29 0.31 2.40 0.00 2.8 CB 14 B5 Oesterle et al B 2.34 444.0 3.67 0.29 0.63 2.40 0.00 7.1 BR 15 B6 Oesterle et al B 2.34 441 3.67 0.29 0.63 2.40 0.13 12.9 CB 16 B7 Oesterle et al B 2.34 458 3.67 0.29 0.63 2.40 0.08 9.2 R 17 B8 Oesterle et al B 2.34 447 3.67 0.29 1.38 2.40 0.09 10.1 BR 18 B9 Oesterle et al B 2.34 430 3.67 0.29 0.63 2.40 0.09 9.7 BR 19 B10 Oesterle et al B 2.34 447 1.97 0.29 0.42 2.40 0.09 7.2 CB 20 F1 Oesterle et al F 2.34 444.7 3.89 0.30 0.71 2.40 0.00 8.4 BR 21 F2 Oesterle et al F 2.34 430 4.35 0.31 0.63 2.40 0.07 9.2 CB 22 WSH1 Dazio et al R 2.02 548 1.32 0.30 0.25 2.28 0.06 2.0 R 23 WSH2 Dazio et al R 2.02 583 1.32 0.30 0.25 2.28 0.06 2.3 BR (psi) Failure Mode 1) N/A g f c = 0.00-0.35 24 WSH3 Dazio et al R 2.02 601 1.54 0.54 0.25 2.28 0.06 2.9 BR 25 WSH4 Dazio et al R 2.02 576 1.54 0.54 0.25 2.28 0.06 2.8 CB 26 WSH5 Dazio et al R 2.02 584 0.67 0.27 0.25 2.28 0.14 2.8 BR 27 WSH6 Dazio et al R 2.02 576 1.54 0.54 0.25 2.26 0.11 3.6 CB 28 W1 Liu R 3.13 458 1.24 0.54 0.40 3.13 0.08 2.3 CB V n,psi = 1.1 12.3 f c Failure modes 29 W2 Liu R 3.13 458 1.24 0.27 0.47 3.13 0.04 1.7 BR 30 W3 Tupper R 3.13 458 1.24 0.54 0.40 3.13 0.08 2.3 CB 31 SW4 Pilakoutas and Elnashai R 2.00 500 6.30 0.79 0.39 2.00 0.00 5.1 CB 32 SW5 Pilakoutas and Elnashai R 2.00 530 9.60 0.79 0.35 2.00 0.00 5.0 DC 33 SW6 Pilakoutas and Elnashai R 2.00 500 6.30 0.79 0.35 2.00 0.00 4.7 DC 34 SW7 Pilakoutas and Elnashai R 2.00 530 9.60 0.79 0.39 2.00 0.00 6.6 BR 35 SW8 Pilakoutas and Elnashai R 2.00 530 6.50 0.79 0.42 2.00 0.00 5.0 BR 36 SW9 Pilakoutas and Elnashai R 2.00 530 6.50 0.79 0.60 2.00 0.00 6.6 CB 37 SW7 Zhang and Wang R 2.14 305 0.88 0.67 1.01 1.80 0.24 6.0 BR 38 SW8 Zhang and Wang R 2.14 305 0.65 0.67 1.01 1.80 0.35 6.4 CB 39 SW9 Zhang and Wang R 2.14 305 1.80 0.67 1.01 1.80 0.24 8.3 CB 40 SRCW12 Zhang and Wang R 2.14 305 1.53 0.67 1.01 1.80 0.35 8.2 CB 27 3D Finite Element Model Experimental Validation: Load-Deformation RW-A15-P10-S78 RW-A15-P2.5-S6.4 R2 h/l = 1.5 v n = 7.8 f c N/A g f c = 7% h/l = 1.5 v n = 6.4 f c N/A g f c =2.5% h/l = 2.34 v n = 2.1 f c N/A g f c = 0 h/l = 3.0 v n = 2.7 f c N/A g f c = 9% RW2 B7 h/l = 2.34 v n = 9.2 f c N/A g f c = 8% WSH4 h/l = 2.0 v n = 2.8 f c N/A g f c = 6% W2 h/l = 3.13 v n = 1.7 f c N/A g f c = 4% SW8 h/l = 2.14 v n = 6.4 f c N/A g f c =35% 28 Wallace, Kolozvari, Safdari, Abdullah 14

3D Finite Element Model Experimental Validation: Global Responses 29 Model Validation Shear and Flexural Deformations RW-A15-P10-S78 Current practice GA eff 30 Wallace, Kolozvari, Safdari, Abdullah 15

3D Finite Element Model Experimental Validation: Strength Loss Typically, model captures initiation of degradation only RW-A15-P10-S78 Concrete crushing under diagonal compression Buckling of boundary reinforcement Lateral instability of the compression zone RW-A15-P10-S78 h/l = 1.5 v n = 7.8 f c N/A g f c = 7% 31 Modeling of Strength Loss Typically Used Approaches Based on material behavior Concrete crushing Rebar buckling Rebar fracture Shear sliding Out-of-plane instability Sensitivity to: mesh size material models material calibration Concrete Crushing Compression controlled Steel Buckling Fracture Steel Require detailed validation 32 Tension controlled Wallace, Kolozvari, Safdari, Abdullah 16

Modeling of Strength Loss Macroscopic Approach: Background UCLA RC Wall Database 176 walls w/ SBE General Yielding Peak Base Shear (kn) 0.8V Peak Cracking Origin Top displacement (mm) Ultimate Residual Drift capacity model v c c L 3.85 h 50 b 8 f w u,max 2 ' c V base vs. top 33 Modeling of Strength Loss Macroscopic Approach: Implementation Flexural Failure Crushing Buckling Lateral instability Implementation Given: l w, b, and f c c c L v 3.85 h 50 b 8 f w u,max 2 ' c Track: c and v u Use rotation/curvature Macro wall element Representative Ground Motion Wallace, Kolozvari, Safdari, Abdullah 17

Model Validation Biaxial Loading Beyer et al. (2008), Constantin (2016) C-shaped walls subjected to biaxial loading Complex loading history Work in progress Other available tests will be considered Model Validation (Preliminary) Biaxial Loading: TUB Wallace, Kolozvari, Safdari, Abdullah 18

Tall Buildings: Modeling + Acceptance January 19, 2018 Tools for Tall Buildings Analysis/Design ETABS Converter OpenSees Model Tools for Tall Buildings Analysis/Design ETABS Converter 2) PROPERTIES Improved Materials 1) GEOMETRY 3) ANALYSIS 4) CHECK DESIGN ( 'c, f 'c) Stress, Compression ( 0, 0) O ( 0+ t, ft) y Tension Not to scale E1= be0 E0 O y Novel Elements 3D FE based P-M-V interaction Failure modes building model Single-click Conversion Wallace, Kolozvari, Safdari, Abdullah Parallel Computing Optimization 19

Summary PEER TBI 2.0, LATBSDC 2017 Coupling beam stiffness Acceptance criteria for force controlled elements B, values Nonlinear Modeling 3D Macro and FE models Strength loss modeling ETABS converter Research needs Biaxial behavior Shear amplification System-level behavior Wallace, Kolozvari, Safdari, Abdullah 20