applied technology council project updates...prepared phase 1 report identified six potential study...

ATC Project Updates: Provisions Update Committee Meeting

Applied Technology Council Project Updates

Provisions Update Committee MeetingJuly 19, 2016

Jon A. HeintzExecutive Director


Agenda

Review Issue Team activities Highlight ATC projects of relevance Outline expected outcomes and timelines


Issue Teams

IT1 – Seismic Performance Objectives IT2 – Seismic Systems and Design Coefficients IT3 – Modal Response Spectrum Analysis IT4 – Shear Wall Design IT5 – Nonstructural Components IT6 – Nonbuilding Structures IT7 – Soil-Structure Interaction Updates IT8 – Base Isolation and Energy Dissipation IT9 – Rigid-Wall Flexible Diaphragm (RWFD)


ATC Projects of Relevance

Primary mission– ATC-116 (IT2 – Systems and Coefficients)– ATC-123 (IT2 – Systems and Coefficients)– ATC-120 (IT5 – Nonstructural)

Bonus information– ATC-58-2 (IT1 – Performance Objectives)– ATC-94 (IT4 – Shear Wall Design)


ATC-116


ATC-116 Project

Solutions to the Issue of Short Period Building Performance– Kircher et al.– Improve simulation of short

period building response (T<0.5 sec)

– Develop design and analytical guidance


ATC-116 Project

Completing third year of a multi-year FEMA-funded effort


ATC-116 Project Context

Quantification of Building Seismic Performance Factors (FEMA P-695, 2009)– Explicit simulation of collapse

Collapse analyses show increased probability of collapse for T<0.5 sec Observed earthquake

performance does not appear to match

0%

5%

10%

15%

20%

25%

30%

35%

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5Design Period, T (seconds)

Col

laps

e P

roba

bilit

y

Bearing Wall Systems (A.7, A.9. A.15)Building Frame Systems (B.2, B.4, B.5, B.25)Moment Frame Systems (C.1, C.5. C.7)


ATC-116 Project Context Possible causes:

– As-built strength of actual buildings is different from archetypes

– Use of overly conservative failure criteria

– Diaphragm flexibility– Soil-structure interaction– Mass distribution– Other sources of flexibility or

displacement (e.g., connections)

204 ft.

204 ft.

24ft.

Column Lines


ATC-116 Objectives

Bridge the gap between simulated and observed performance of short period buildings– Improve simulation techniques to better

match observed performance – Change design provisions to improve

performance (if needed)


ATC-116 Status

Completed studies of wood frame buildings for:– Configuration (height/interior walls)– Collapse Displacement Capacity– SSI/Foundation Flexibility– Imperfect Connectivity– Interior/Exterior Wall Finishes

Currently developing recommendations for wood systems and initiating study on masonry systems


ATC-116 Results – Sound Bite

0%

5%

10%

15%

20%

25%

30%

35%

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5Design Period, T (seconds)

Col

laps

e P

roba

bilit

y

Bearing Wall Systems (A.7, A.9. A.15)Building Frame Systems (B.2, B.4, B.5, B.25)Moment Frame Systems (C.1, C.5. C.7)


ATC-116 Findings

Issues that mattered for wood frame buildings:– Configuration (height/interior walls)– Collapse Displacement Capacity– SSI/Foundation Flexibility– Imperfect Connectivity– Interior/Exterior Wall Finishes


ATC-116 Implications

Findings related to Configuration:– All walls/finishes matter– Single-story archetypes performed well– Multi-story archetypes developed first

story mechanisms– Taller (4-story) archetypes did not meet

collapse safety criteria Potential code implications

– Adjust design rules in lower stories of multi-story stacked systems??



Findings related to Finishes:– Nonstructural finishes (stucco/gyp) are a

significant contributor to total strength– Finishes were significant contributors

(positive and negative) to collapse behavior of multi-story archetypes

Potential code implications– Adjust design rules to account for

nonstructural finishes??


ATC-116 Implications Findings related to Collapse Displacement

Capacity:– FEMA P-695 studies to date have used overly

conservative failure criteria

0 5 10 150

2

4

6

8

10

12

14

16

18

Drift (%)

For

ce (

kip

)

OSB NonstrucOSB Low

OSB Medium

OSB High

Gyp MinGyp Max

Gyp Nonstruc

StuccoSiding



Findings related to Collapse Displacement Capacity (cont’d):– If you increase residual strength and

displacement capacity, collapse capacity goes up (magic number: 30%)

– Possible sources of residual strength attributed to: components; system effects

Potential code implications– Consider in analysis/design or not??– Testing needed to quantify


ATC-116 Schedule By September 2016

– Develop preliminary recommendations for implementation of findings for wood systems

– Possible workshop to test ideas By September 2017

– Investigation of short-period masonry systems


ATC-123


ATC-123 Project

Improving Seismic Design of Buildings With Configuration Irregularities– Valley et al.– Based on recommendations

in the NIST-GCR-917-23 Roadmap (BSSC project)

– Calibrate quantitative triggers related to irregularities


ATC-123 Project

Completing first year of a three-year FEMA-funded effort


ATC-123 Expected Outcomes Identify baseline collapse probability for

selected systems Quantify change in collapse probability

as irregularities are introduced Determine revised irregularity criteria

that result in no change in collapse probability Determine revised design criteria to

adjust collapse probability for irregular conditions


ATC-123 Scope of Work 30 baseline archetypical systems

– RCMF, SMF, RCSW, RCMF+RCSW– Special and ordinary variants– 1-story to 20-story height variants– ELF and MRS design variants– SDC D and SDC B variants

Parametric introduction of horizontal and vertical irregularities


ATC-123 Scope of Work



– All baseline designs complete– Analysis results for RCSW system with H1

(torsional stiffness) irregularity– Analysis results for SMF and RCMF

systems with V2 (mass) irregularity By September 2017

– All other system/irregularity combinations complete


ATC-120


ATC-120 Project

Seismic Analysis and Design of Nonstructural Components and Systems– Phipps et al.– Improve nonstructural system

design for public safety and economic welfare

– Investigate disconnect between design and observed (or expected) performance


ATC-120 Project

Half-way through a three-year NIST-funded effort


ATC-120 Project Status Prepared Phase 1 Report Identified six potential

study recommendations Selected two:

– Develop nonstructural performance objectives

– Conduct holistic assessment of current code design approaches


ATC-120 Scope of Work Performance Objectives

– To create a set of performance objectives for nonstructural components and systems that covers all components in all seismic design categories that has broad acceptance and dovetails with proposed design recommendations


ATC-120 Scope of Work Holistic Assessment

– Determine the adequacy of current nonstructural design provisions using analytical, experience, and testing data

– Revise nonstructural provisions to provide appropriate seismic performance and improve usability for typical users

– Identify areas of further study needed


Adequacy of current nonstructural design provisions

Develop an analytical method that will predict nonstructural component response for generic structures with reasonable accuracy (Task 39.14.2)


Determine if the design equations are appropriate(Task 39.14.3)



Determine if the procedures produce compatible design demands for different elements in the load path (Tasks 39.14.4 and 39.14.5)

"A" "B" "C"1

1

Support 1-SectionA

2'-6

"

2'-6"

Rp = 2.5, 3, 4.5, 6, 9,or 12

Rp = 2.5, 3, 4.5, 6, 9,or 12

Rp = 2.5, 3, 4.5, 6




– Performance objective and holistic studies planned and initiated

By September 2017– Performance objective and holistic studies

completed


Bonus Information


IT1 - ATC-58-2 Project

Phase 2: Development of Performance-Based Seismic Design Guidelines– Hamburger et al.– Stakeholder interactions– Exercising the FEMA P-58

Methodology in a design context

– Benchmarking code performance


ATC-58-2 Code Benchmarking

Identified parametric design space of code-conforming systems


Initial Runs – Phase I

Structural Types RC Wall RC SMRF

CMU Wall SCBF OBF BRBF

Steel SMRF

Lt Frame

Stories II IV II IV II IV II IV II IV II IV II IV II IV Total2 3 3 3 3 3 3 3 3 3 1 3 3 3 3 3 3 95 3 3 3 3 3 3 3 3 3 1 3 3 3 3 3 912 3 3 3 3 3 3 3 3 3 3 3 3 9

9 9 9 9 9 9 9 9 6 2 9 9 9 9 6 3 27

• High SDC D, SDC D, and Low SDC D • 4 strength/stiffness combinations for each subset• 11 intensities (10%, 20%, 30%, 50%, 60%, 67%, 70%, 80%, 90%,

and100% MCE)

Semi complete Completed


12‐story SMRF, Point 3: Median Loss Ratios

Case 2

Case 4

Case 1 Case 3

Case 5

old PACT ‐ old fragilities new PACT ‐ old fragilities

Case 8

new PACT updated fragilities 1

F&L ‐ new PACT ‐ updated fragilities 1 new PACT ‐ updated fragilities 2 new PACT ‐ updated fragilities 3 ‐ Un‐Correlated Fragilities‐Factored T1


ATC-58-2 Schedule

Running code benchmarking analyses Summer 2016 Look for more information soon


Performance of Reinforced Concrete Buildings in the 2010 Chile Earthquake– Maffei et al.– Evaluate critical issues in the

design of reinforced concrete walls and develop improved wall design requirements

IT4 – ATC-94 Project


Group 1a – developed simple relation for bar buckling

Group 1b – developed simple relation for wall buckling

Group 2a – developed new ASCE 31 checklist criteria for building irregularities

Group 2b – recommended advanced simulation techniques for shear wall behaviors

10

25

20

15

5

00.00 0.01 0.02 0.03 0.04

Maximum tensile strain, sm

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ATC-94 Areas of Work


Thank You!

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