overview of fema p-58 (atc-58) damage/loss methodology …...2 p-58 is a performance prediction...

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Overview of FEMA P-58 (ATC-58) Damage/Loss Methodology

and Plans for Enabling Commercial Software

Curt B. Haselton, PhD, PE

CSU, Chico

Jack W. Baker, PhD Stanford University

SEAOC Committee Meeting

Presentation on FEMA P-58 and SP3

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P-58 is a performance prediction methodology based on a 10-year FEMA study (enabled by much previous research). P-58 is an alternative to other experience-based or

judgment-based methods (e.g. HAZUS, ATC-13, etc.). P-58 is tailored to building-specific analysis (as opposed to

regional/portfolio analyses). P-58 provides information useful for seismic ratings. ATC is currently working on another 5-year effort to further

advance the methodology, implementation, ease of use.

The REDi Rating System (this afternoon) also uses a modified version of FEMA P-58 in their rating process.

Overview of FEMA P-58

SEAOC Committee Meeting Presentation on FEMA P-58 and SP3

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FEMA P-58 Output Results: • Losses ($) [Repair Cost Rating] • Fatalities & injuries [Safety Rating] • Repair time & red tagging [Recovery Time

Rating (some translation required)] Types of analysis results:

• Intensity-based (e.g. DBE) [Approach for ratings] • Time-based (annualized values) • Scenario-based (for a given event)

Overview of FEMA P-58


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Sample results (12-story RC frame):

FEMA P-58: Output Examples


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Dig as deep as you like…

FEMA P-58: Output Examples


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Hazard and Ground Motions • Soil and hazard curve • Ground motions (if needed)

FEMA P-58: Methodology


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Structural Responses • Option #1: Response-history • Option #2: Simplified method


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Damage Prediction • Contents (str. and non-str.) • Fragility curves



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Loss Estimation (loss curves) and other consequences



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Monte Carlo Simulation used

(“roll dice” thousands of times).

Each “dice roll” gives a single observation of

losses (and other consequences).

Putting all of the “dice rolls” together gives solid statistical information on

performance.


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Objective process based on extensive test data and research. Quantitative performance information:

• Dig as deep as you like. • Tools to communicate with owners. • Solid statistical basis.

FEMA P-58: Benefits

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FEMA P-58: Perceived “Difficulty”

I need to hire a geotech to do this…?!?!

I need to do a response-history analysis…?!?!

I need to count and enter every foot of partition wall and other contents…?!?!






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It may not be as hard to implement FEMA P-58 as some currently perceive it to be.

The “What If” Question:

• What if we had a stream-lined FEMA P-58 analysis that could be done in hours rather than days (and provide all of the same benefits)?

FEMA P-58: Perceived “Difficulty”


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Based on my discussions with practitioners, it looks like most of the barriers to FEMA P-58 use are related to software and ease-of-use. FEMA has funded additional development, currently

working on both methodology advancements and design aids (to improve ease of use, etc.). FEMA and ATC have created a useful methodology

but are not in the business of maintaining software. For our profession to move forward with use of FEMA

P-58 methods, someone needs to step-up to provide/maintain user-friendly enabling software.

My Thinking Over Past Couple Years


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In February, Jack Baker and I decided to work on filling this needed role by: a) Creating user-friendly software to implement P-58. b) Maintaining software over time (fragilities, etc.). c) Improving and extending the methodology in the

future after ATC/FEMA work is done (improvements, extensions desired by SE’s, etc.).

Timing: Our timing lines up well with the USRC building rating system work, so we would like to help support this process.

My Thinking Over Past Couple Years


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Loss Estimation (loss curves)

Software Implementation of FEMA P-58

Soil and hazard curves embedded.

Simplified method embedded (only need period, mode shape, strength, yield drift).

Structural and non-structural contents estimated and pre-

populated.

Two-level structure: (1) Simple (basic rating, prelim. design, PML) (2) Refine and go as deep as you like (full new PBD).

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Status and Timeline: • February: Started software work. • April: Secured a National Science Foundation

research commercialization grant for funding. • Current: Active development (Jack, me, team of 7). • November: Commercial Beta release.

ATC/FEMA: Being done in coordination with ATC (so all

pulling in same direction) but not funded by ATC (because needs to become a commercial tool to be sustainable).

Status and Timeline


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Draft SP3 Tool


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Our goal is to enable/support the use of newly-emerging tools like P-58 in our profession (both for ratings and for new performance-based design). We are still in active development, so please:

• Let us know how we can tailor SP3 to be most useful for our structural engineering profession.

• I would love to meet with you if you have advice!

E-mail: [email protected], [email protected]

Cell: (530) 514-8980

Next Steps


overview of fema p-58 (atc-58) damage/loss methodology …...2 p-58 is a performance prediction...

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