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PEER 2002 Annual Meeting

This presentation discusses the practical application of the PEER Limit State Checking Methodology, based on results from PEER Core and PEER/PG&E Lifelines projects. It explores several performance levels, tolerable ground motion probabilities, and LRFD-like formulations of performance states.

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PEER 2002 Annual Meeting

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  1. PEER 2002 Annual Meeting Practical Application of the PEER Limit State Checking Methodolgy Allin Cornell with F. Jalayer, M. Motahari, D. Vamvatsikos, and P. Bazzurro Stanford University Based on Results from a PEER Core Project and PEER/PG&E Lifelines Project

  2. PBEE Limit State Options Current (FEMA 273): Several Performance Levels and Tolerable Ground Motion Probabilities PEER PROPOSAL Several Performance Levels and Tolerable Performance State Probabilities in “LRFD-like” Form

  3. P a h P max ) = Pr [S Maximum Interstory drift Angle Components of Drift-Based Assessment 0 S b h = a S a q max h C 0 q | s P a LS l q (s > s ] , a a a S a max

  4. Median Capacity Median Demand under records with Sa at hazard level Pfo The Safety Checking Equation

  5. W 24x162 Box 18x18x 3/4 W 24x76 14’ W 24x76 14’ W 33x118 15’6” 32’6’’ 28’ 32’6’’ PG&E Substation Frame Example: PG&E 3-Story Pre-Northridge SMRF

  6. 2% in 50 years = 0.0004 / year 1.7g Tolerable Probability Check: 2% in 50 Years

  7. DS1 DS2 Static Pushover: Capacity Focus here: Damage State 4: Local Collapse: First loss of shear tab It occurs at local rotation of 0.07 or Roof Drift of 0.048 Intact SPO and Damage States 1000 800 DS4 DS3 600 Base Shear ( Kips ) 400 200 0 0.00 0.01 0.02 0.03 0.04 0.05 Roof Drift

  8. Demand: Static (SPO) to Dynamic (IDA) • “SPO2IDA” - an instantaneous web-site tool See Poster by D. Vamvatsikos

  9. BetaD = ln (4/2.7)= 0.39 Median 2.7% 84th %-tile 4.0% Roof Drift ( % ) Dynamic Demand Results for This Structure 2.5 Median IDA 2.0 84% IDA Sa = 1.7 g 1.7 1.5 Sa ( g ) 1.0 0.5 Intact SPO 0.0 0.0 1.0 2.0 3.0 4.0 5.0

  10. Limit State Safety Check

  11. 105 105 105 105 105 106 157 241 241 241 Seismic Design Assessment of RC Structures. (Holiday Inn Hotel in Van Nuys) • Beam Column Model with Stiffness and Strength Degradation in Shear and Flexure (but no axial column failure modes!) using DRAIN2D-UW by J. Pincheira et al.

  12. Tolerable Probability: 0.03 per year 0.03 / year 0.4g

  13. Capacity: Onset of Story Mechanism 0.75%

  14. Van Nuys: Drift Demand (via NLD Analysis) Dispersion; 0.39 O.4g Median: 0.46%

  15. Note addition of epistemic uncertainty in demand estimation Limit State Safety Check

  16. Safe if: Probability-Based Assessment Basis

  17. Notes The Estimation of Epistemic Uncertainties Demands Good Judgement For Codified Versions Some of These Demand and Capacity Betas Might be Tabulated In the PEER/PG&E Buildings Fragility Project we are Taking a Slightly Different Tact Based on the Same Methods. The Objective is to Establish the Likelihoods of the Building Being Yellow or Red Tagged

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