Research Needs ASCE 41-13: Seismic Evaluation and

Retrofit of Existing Buildings

2012 ACEHR Meeting

Robert Pekelnicky, SE

ASCE/SEI Seismic Rehabilitation Standards Committee

2012 ACEHR – ASCE 41 Research Needs

Inconsistencies

2012 ACEHR – ASCE 41 Research Needs

Combine ASCE 31 & ASCE 41

2012 ACEHR – ASCE 41 Research Needs

Benefits of ASCE 41-13

• Consistent Evaluation and Retrofit Provisions

• Explicit direction for existing buildings of different risk categories

• Explicit “New Design Code” equivalent performance objectives

• Greater consistency with ASCE 7

• Less conservative Tier 1 Life Safety provisions

• Updated technical provisions

2012 ACEHR – ASCE 41 Research Needs

Research Needs

2012 ACEHR – ASCE 41 Research Needs

Calibrate Collapse Prevention

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0

Collapse Spectral Acceleration (g)

Col

laps

e Pr

obab

ility

.

Comprehensive Collapse DataLognormal Distribution

Does ASCE 41 CP provide 10% probability of collapse?

Figure courtesy of Charlie Kircher

2012 ACEHR – ASCE 41 Research Needs

Global Building Criteria

When the whole is better than the sum of its parts.

2012 ACEHR – ASCE 41 Research Needs

Revise Modeling Parameters

Most Parameters Unchanged in 15 years

2012 ACEHR – ASCE 41 Research Needs

Revise Modeling Parameters

Change to Parameters That Are Ideal For Nonlinear Response History

2012 ACEHR – ASCE 41 Research Needs

Concrete Shear Wall Criteria

Many feel current criteria is too conservative

2012 ACEHR – ASCE 41 Research Needs

Reinforced Masonry Wall Criteria

2012 ACEHR – ASCE 41 Research Needs

Liquefaction Effects on Buildings

2012 ACEHR – ASCE 41 Research Needs

Nonstructural Design Forces

2012 ACEHR – ASCE 41 Research Needs

Tier 1 & Tier 2 Calibration

A

B

C

D

E

11 10 9 8 7 6 5 4

Transfer girders@ Level 12

Columns of perimetermoment frameabove Level 14

Shear wallsbelow Level 14

WallD5-6

Plan View Elevation View

Figure courtesy of Ken Elwood

2012 ACEHR – ASCE 41 Research Needs

Material Variability & Knowledge Factor

Figure courtesy of Bruce Ellingwood

2012 ACEHR – ASCE 41 Research Needs

Method to Assess Killer Buildings

From Beca 2011

2012 ACEHR – ASCE 41 Research Needs

Concrete Encased Steel with & without Brick Infill

2012 ACEHR – ASCE 41 Research Needs

Concrete Frames with Brick Infill

Nondestructive Testing

More Nonductile Concrete Research

Research Needs ASCE 41-13: Seismic Evaluation and

Retrofit of Existing Buildings

2012 ACEHR Meeting

Thank you…any questions?