detailed benchmarking and validation studies of …...hazus overview • developed by fema and first...

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Dustin Cook, PEPh.D. Student @ University of Colorado, Boulder

www.hbrisk.com

SP3-RiskModel Webinar Series

Detailed Benchmarking and Validation Studies of the SP3-RiskModel:

An Overview of Findings

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Presenters

Dustin Cook, PE: HB-Risk team member and graduate student at CU Boulder. Currently partnering with HB-Risk to benchmark and validate the FEMA P-58 methodology using the SP3-RiskModel.

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All phone lines are muted Questions are highly encouraged (answered at end) Handouts are available – presentation slides Webinar is recorded and video will be distributed

Housekeeping

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Questions:• Please use questions tab and we

will address as many as we can at the end of the webinar.

• For further questions, or for feedback on forward development, please contact Angie at HB-Risk and she can connect you with the right person ([email protected]).

Housekeeping

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Overview of SP3-RiskModel Webinar Series:1) SP3-RiskModel – Introduction to the Software and a Look

“Under the Hood” at the Technical Details [available online at www.hbrisk.com]

2) Detailed Benchmarking and Validation Studies of the SP3-RiskModel – An Overview of Findings [today]

Housekeeping

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Goal: To verify loss results from FEMA P-58 and the SP3-RiskModel against current knowledge base.

Scope: Compare FEMA P-58 losses using the SP3-RiskModel to Hazus for a broad range of buildings and

locations.

Project Overview

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Initial Findings from the Study

1. Mean losses from FEMA P-58 compare well with Hazus, on average, for building types and sites where Hazus developers had the most empirical earthquake data available, such as:

I. Buildings constructed between 1941 and 1996.

II. Low rise wood light frame structures.

III. Buildings in California.

2. Many of the differences in losses stem from FEMA P-58 sensitivity to building-specific characteristics, as compared with Hazus losses based on building classification.

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Outline

1. Short overview of the FEMA P-58 method, the SP3-RiskModel, and Hazus.

2. Methodology for benchmarking losses.3. Results of Study.4. Future Work.

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FEMA P-58 is a probabilistic performance prediction methodology (15 year, $16M+ invested, ~100+ on the team)

FEMA P-58 is tailored for building-specific analysis (in contrast to most risk assessment methods)

FEMA P-58 output results:• Repair costs• Repair time• Safety: Fatalities &

injuries

FEMA P-58 Overview

Overview Method Results

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FEMA P-58 Workflow

Site Hazard Structural Responses

Structural Components & Fragilities

Nonstructural Components & Fragilities

Building-Specific Vulnerability

Curves

Full distributions of losses and repair

times, and expected annual values.

FEMA P-58 Monte Carlo Analysis

ENGINE


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Curves



Basic Building and Site

Information

(e.g. location, construction year, etc.)

Additional Secondary Modifiers

(more building and site info.)

SP3 BUILDING-SPECIFIC RISK MODEL

Full FEMA P-58 engineering-based risk assessment framework

Automation through many research-backed analytical SP3 Engines and

SP3 Databases

When full automation is used, this provides building-specific and site-

specific vulnerability curves for large inventories

The New SP3-RiskModel


Structural Components & Fragilities

Nonstructural Components & Fragilities FEMA P-58 Monte

Carlo Analysis ENGINE


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Nonstructural Components & Fragilities



PGA and Sa for many

hazard levels

Site Hazards Database

Soil type

Structural responses

Structural Response Prediction ENGINE

Structural Responses Database

Structural Models

Database

Dynamic Properties

ENGINE

Building Code Design Database

Site Soil DB

Struct. comp. inventory

Building strength

Experimental Test Database

Structural Designs

Database

Site-specific EQ and wind

strength design

Over-strength by bldg. type, location, etc.

Site-specific EQ and wind drift

design

Building stiffness (T1)

Building modal properties

(T2-T3, φ1-φ3)

Strength and stiffness of gravity and non-str.

components

Site-specific non-structural comp. design

Comp. Popul.

ENGINES

Non-str. comp. inventoryStruct. comp.

fragilities

The New SP3-RiskModel

Non-str. comp. fragilities

Component Fragility

Database

Structural Components & Fragilities FEMA P-58 Monte

Carlo Analysis ENGINE

Additional Secondary Modifiers

(more building and site info.)

Basic Building and Site

Information

(e.g. location, construction year, etc.)


Curves

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Hazus Overview

• Developed by FEMA and first released in 1997.• Estimates losses using defined building damage

functions that are a function of the building classification and the hazard at the site.

• The Hazus method went through a rigorous calibration process to empirical earthquake data available at the time, such as:– 1933 Long Beach– 1971 San Fernando– 1983 Coalinga– 1984 Morgan Hill– 1989 Loma Prieta– 1994 Northridge earthquakes


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Hazus Building Classification

Building Classification

Damage StatesOverview Method Results

Building Structural System

Building Occupancy

Building Age / Design Level

W1 Wood Light Frame

S1L Low-Rise Steel Moment Frame

S1M Mid-Rise Steel Moment Frame

S1H High-Rise Steel Moment Frame

C2L Low-Rise Concrete Shear Wall

C2M Mid-Rise Concrete Shear Wall

C2H High-Rise Concrete Shear Wall

… …

RES1 Single Family Dwelling

RES3 Multi Family Dwelling

COM1 Retail Trade

COM2 Wholesale Trade

COM4 Proffesional/Technical Services

COM6 Hospital

EDU1 Grade Schools

… …

UBC Seismic

ZonePost-1975 1941-1975 Pre-1941

4 High-Code Moderate-Code

Pre-Code

3 Moderate-Code Moderate-Code2B Moderate-Code Low-Code2A Low-Code Low-Code1 Low-Code Pre-Code0 Pre-Code Pre-Code

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Hazus Workflow


Damage StatesOverview Method Results

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Hazus Workflow


Capacity Spectrum

Damage States

Estimated Losses


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Hazus Workflow


Equivalent PGA Damage States

Estimated Losses

Peak Ground Acceleration


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SP3-RiskModel vs. Hazus Methodology


(Equivalent PGA Damage Curves)

Based on pre-defined damage

functions calibrated to earthquake data

Based on structural mechanics, statistical

analysis, nonlinear analysis and expert

judgement

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Building Classification vs. Building Characteristics

Building Occupancy

Year of Construction

UBC Seismic

Zone

Building Structural

System

Building Structural

System

Building Occupancy

Year of Construction

Seismic Design Values

Building Geometry

Component Layout

Fundamental Periods

Base Shear Strength

Overstrength

Building Irregularities

Building Component Fragilities

Building Value

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• Compares losses from the SP3-RiskModel to Hazus in terms of repair costs for a set of over 55,000 models.

• Models represent typical structures for 23 different structural systems across 36 sites in the U.S., designed from 1933 to 2016, from 1 to 20 stories in height.

• All of the models assessed as part of this study represent regular structures (i.e. without irregularities).

Benchmarking Methodology


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FEMA P-58 Losses Increase with Seismicity

Salt Lake City

Seattle

Oakland


FEMA P-58 mean losses buildings of various ages and sites for a 10% in 50 hazard.

Wood Light Frame RC Moment Frame

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FEMA P-58 Losses Increase with Seismicity


FEMA P-58 mean losses for a 2016 reinforced concrete moment frame at various sites for a 10% in 50 hazard

Designed without deterministic seismic design values (fully probabilistic).

Designed using current deterministic seismic design values.

RC Moment FrameRC Moment Frame

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FEMA P-58 Losses Decrease with Age and Height


Average FEMA P-58 mean losses for reinforced concrete moment frames at

various sites, ages, and heights, for a 10% in 50 hazard.

RC Moment Frame

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FEMA P-58 v Hazus Loss


FEMA P-58 mean losses compared to Hazus losses for wood light frame

buildings at a 10% in 50 hazard.

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FEMA P-58 mean losses compared to Hazus losses for wood light frame

buildings, for various age classifications, at a 10% in 50 hazard.

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FEMA P-58 mean losses compared to Hazus losses for reinforced concrete

moment frames, for various age classifications, at a 10% in 50 hazard.

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FEMA P-58 v Hazus Loss: Per Region


Average FEMA P-58 mean losses compared to Average Hazus losses for reinforced concrete moment frames, for various regions, at a 10% in 50 hazard.

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Why Building-Specific Attributes Matter

Model A:2016 - 8 Story RCMF Office in San Jose

Model B:2016 - 8 Story RCMF Office in Los Angeles


FEMA P-58 mean losses for a 2016 reinforced concrete moment frame at various sites for a10% in 50 hazard.

Model A Model BPGA (g) 0.53 0.52Sd1 (g) 0.6 0.84

Strength (g) 0.11 0.15Period (s) 1.64 1.36P-58 Loss 0.27 0.15

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FEMA P-58 mean losses for a 2016 reinforced concrete moment frame at various sites for a10% in 50 hazard.



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Model C:2016 – 20 Story RCMF Office in San Jose

FEMA P-58 provides loss estimates based on the dynamics of the specific

structure, such as building height.


Model A Model CPGA (g) 0.53 0.53Sd1 (g) 0.6 0.6



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Model D:1976 UBC – 8 Story RCMF in Los Angeles

Model E:1997 UBC – 8 Story RCMF in Los Angeles

FEMA P-58 provides loss estimates based on

characteristics of the specific building age and building code.

Model D Model EPGA (g) 0.52 0.52Z-factor 1.0 0.4K-factor 1.33 --R-factor -- 8.5



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Case Study of Building Specific Attributes


FEMA P-58 mean losses compared to Hazus losses for a 1985 precast tilt-up retail store in Los Angeles, for various aspect ratios, at a 10% in 50 hazard.

FEMA P-58 mean losses compared to Hazus losses for a 1985 reinforced concrete

moment frame office in Los Angeles, for various heights, at a 10% in 50 hazard.

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Conclusions

1. Mean losses from FEMA P-58 compare well with Hazus, on average, for building types and sites where Hazus developers had the most empirical earthquake data available, such as:

I. Buildings constructed between 1941 and 1996.

II. Low rise wood light frame structures.

III. Buildings in California.

2. Many of the differences in losses stem from FEMA P-58 sensitivity to building-specific characteristics, as compared with Hazus losses based on building classification.

3. For older (pre 1941) buildings, FEMA P-58 predicts lower losses than Hazus, likely due to the assumption of “regular” buildings in this study, which may not represent typical older construction.

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Next Phase

• Run large Northridge scenario using the SP3-RiskModel and compare with post-earthquake empirical loss data.

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Thank You

For further questions, or for feedback on forward development, please contact Angie at HB-Risk and she can connect you with

the right person ([email protected]).

detailed benchmarking and validation studies of …...hazus overview • developed by fema and first...

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