assessment existing building,laatsch

8/6/2019 Assessment Existing Building,Laatsch

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2009 WSSPC Annual MeetingFebruary 12, 2009

Earthquakes and Existing Buildings:

Where Do We Stand?


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Ear t hquak es and Ex is t ing Bu i ldingsEar t hquak es and Ex is t ing Bu i ld ings

Progress being made but theres a long way to go

2006 National Research Council reports states the economical retrofit of existing structures is

perhaps the most important issue facing earthquake-

prone communities today. A new generation ofretrofit technologies that cost less than existing, lesseffective techniques but preserve cultural andarchitectural resources and protect real estate

investments from total loss is long overdue If these are some of the challenges then what are

possible solutions?


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Ear t hquak es and Ex is t ing Bu i ldingsEar t hquak es and Ex is t ing Bu i ld ings

Whats the size of the problem? HAZUS AAL Study (FEMA P-366/April

2008) $5.3B annual losses 2/3 in California

HAZUS study of Utahs Wasatch Front

Estimates daytime event will causemore than 6,000 deaths w/ mostcasualties due to collapsedcommercial and educational buildings

estimates 80% of severe casualties inthe scenario earthquake caused byURMs

HAZUS-MH determined that casualtiesfrom schools would be approximately1,100.


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FEMA Ex ist ing Bui l d ings Program What s Been Done So FarFEMA Ex ist ing Bui ld ings Program What s Been Done So Far

FEMA 178 NEHRP Handbook for the Seismic Evaluationof Existing Buildings, (1992)

FEMA 273, 274 NEHRP Guidelines for the SeismicRehabilitation of Buildings, NEHRP

Commentary on the Guidelines for theSeismic Rehabilitation of Buildings, (1997)

FEMA 154 Rapid Visual Screening of Buildings for PotentialSeismic Hazards: A Handbook, (1988, 2002)

FEMA 310 Handbook for the Seismic Evaluation ofBuildings, (1998)

FEMA 237 Seismic Rehabilitation of BuildingsPhase I:

Issues Identification and Resolution

Guidance documents since 1985


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FEMA Ex ist ing Bui l d ings Program What s Been Done So FarFEMA Ex ist ing Bui ld ings Program What s Been Done So Far

FEMA 172 NEHRP Handbook for Seismic Rehabilitation of

Existing Buildings (1992)

FEMA 156, 157 Typical Costs for Seismic Rehabilitation of ExistingBuildings, Volume I: Summary, July and

Supporting Documentation, (year) Second edition,1994 (Online calculator tool 2006)

FEMA 227, 228 A Benefit-Cost Model for the SeismicRehabilitation of Buildings: A Users Manual, and

Supporting Documentation.

FEMA 255. 256

(EO 12941)

Seismic Rehabilitation of Federal Buildings: ABenefit/Cost Model, Volume I: A Users Manual,and Supporting Documentation (1994)

Guidance documents since 1985


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FEMA Ex is t ing Bui ld ing Program What s Been Done So FarFEMA Ex is t ing Bui ld ing Program What s Been Done So Far

1985 1988

19942006

2007

2002

2000 2003

Strate

gicPlan

FEMA

315

Techniq

uesforSe

ismic

Rehabilita

tion(

FEMA

172)

1992

EO

12941EB

Actio

n

Plan/W

orksh

op

1997

Typic

alCo

stsforS

R

(FEMA

156)

1998

RapidVis

ualS

creening

(FEM

A15

4)

NonStru

ctural

(2nd)

1994

RapidVis

ualS

creening

(FEMA

154)Up

date

Handbook forSeismic Evaluation

(FEMA 178)

ASCE 31

Prestandard for SR(FEMA 356)

Prestandard forEvaluation(FEMA 310)

Guidelines for SR(FEMA 273, 274)

ASCE 41

EBActio

n

Plan/W

orksh

op

NEH

RPWork

sh

ATC

71

Increme

ntalS

eismi

cRehab

(FEMA

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Ex is t ing Bu i ld ings Des ign Guidanc e,s t andards and m odel bu i lding c odesEx is t ing Bu i ld ings Des ign Guidanc e,s t andards and m odel bu i ld ing c odesFEMA EB Guidance has been incorporated intoFEMA EB Guidance has been incorporated intoNational Consensus Standards and now referencedNational Consensus Standards and now referencedin IEBC, IBC, and NFPA 5000in IEBC, IBC, and NFPA 5000


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Ex ist ing Bui l d ings and NEHRPEx ist ing Bui l d ings and NEHRP

NEHRP Strategic Plan

Strategic Priority:Improve Techniques forEvaluating and Rehabilitating

Existing Buildings Objective 7 Develop tools to

improve the seismic performance ofbuildings and other structures

FEMA E i i B i ld i P


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FEMA Ex ist ing Bu i ld ings ProgramSom e k ey quest ionsFEMA Ex ist ing Bui ld ings ProgramSom e k ey quest ions

What are the biggest barriers to the implementation of seismicrehabilitation, including technical, practical, and regulatorychallenges?

What is our vision for the future of seismic rehabilitationresearch, practice, and implementation?

What types of guidance, tools and products would best helpachieve this vision?

Who are our partners? How can we find common objectives andstrategies to improve progress toward earthquake risk reductionin existing buildings?


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FEMA Ex ist ing Bu i ld ings ProgramNex t St eps ATC 71FEMA Ex ist ing Bui ld ings ProgramNex t St eps ATC 71

Comprehensive effort to analyze/prioritize investmentin guidance development and technology transfer for

existing buildings Workshop Meeting the Challenges of Existing

Buildings

Develop an Action Plan for Seismic Rehabilitation underway

Updating FEMAs Seismic Rehabilitation Guidance Program Definition and Guidance Development

New and creative implementation strategies for thecreation and maintenance of rehabilitation guidance

More effectively leverage FEMAs resources with our

partners


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FEMA Ex ist ing Bui ld ings ProgramNex t St eps ATC 71FEMA Ex ist ing Bui ld ings ProgramNex t St eps ATC 71

NEHRP Workshop

Status Report (Technology, Practice, Policy)

Action Report

Implementation


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FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t NEHRP Work shopFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t NEHRP Work shop

NEHRP Workshop (ATC and EERI)

Meeting the Challenges of ExistingBuildings, September, 2007

Participants-Stakeholders: Earthquake/Structural Engineering Practitioners

Regulatory (Building Officials) Public Policy/Social Science experts

Research/Academia (ATC 73)

Building Owner and Manager/Developers

FEMA E i i B i ld i ATC P jFEMA E i t i B i ld i ATC 71 P j t


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Workshop Framework:

Open Forum, Discussions and Electronic Voting Breakout Sessions

Identification of Issues and Impediments and

priorities:

TechnicalTechnical

PracticalPractical

Regulatory/Public PolicyRegulatory/Public Policy

ResearchResearch(ATC 73(ATC 73--NSF)NSF)


FEMA E i t i B i ld i ATC 71 P j tFEMA E i t i B i ld i ATC 71 P j t


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Technical: Engineering Guidelines, procedures,analytical procedures, algorithms, forming technical basis for

evaluation and rehabilitation. Practical: Applicationof technical resources to design and

construction practice.

Regulatory/Public Policy: Building codes, policydevelopment, legislative, economic, and social issues thataffect building design/construction/investment decisions.

Research: System, material testing, experimentalinvestigation, new knowledge development activities related toseismic behavior of buildings, components, ground motionand social science issues.



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Plenary Voting: Most Valuable Contribution tomeet EB Seismic Challenges?

FEMA E i t i B i ld i ATC 71 P j tFEMA Ex is t ing Bui ld ings ATC 71 Pro jec t


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Workshop Plenary Voting: BiggestImpediment to Mitigation?

FEMA Ex is t ing Bui ld ings ATC 71 Pro jec tFEMA Ex is t ing Bui ld ings ATC 71 Pro jec t


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Technical Issues Strong Support for:

Case Studies to validate ASCE 31, 41

Building Rating System that could be understood

by tenants, owners, and other stakeholders More clarification of whether acceptance criteria inthe standards are based on testing or expert

opinion.



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Technical Group Highest Priority Needs Focused Case Studies

Identify shortcomings in the current standards Demonstrating rehabilitation technologies

Generate consistent information for stds comm and public policy

Transition research into practice

Translation into practical tools in a more timely manner. Process should fit within context of standards adoption practice

Development of Application Examples Example manuals to introduce concepts and terminology:

ASCE 31 & 41 analysis procedures and design criteria Nonlinear modeling and analysis of new and existing elements

Establish relationships between component response andsystem performance



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Practical Issues Strong Support for:

Peer review guidelines

Prescriptive (simplified) procedures for select

building types.

Development of example applications.

FEMA Ex is t ing Bui ld ings ATC 71 Pro jec tFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t


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Practical Group Highest Priority Needs Development of building specific loss estimation procedures

Education and training Stakeholders (Owners, tenants, decision makers)

Engineers, Code Officials, Colleges/Universities

System to incorporate engineering judgment into standards

Business continuity guidelines Assist decision makers to examine risk and weigh benefits and costs.

Consistency in code enforcement Inconsistencies in interpretation of ASCE 31, 41

Incremental seismic mitigation strategies Improve evaluation and rehabilitation of nonstructural components

FEMA Ex is t ing Bui ld ings ATC 71 Pro jec tFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t


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Regulatory Issues Strong Support for:

Consistency in adoption/enforcement of seismicprovisions across jurisdictions

Development of a Rating System to communicate

with decision makers the advantages of seismicrehabilitation

More access to training for Plan Reviewers

Peer Review (mandated)

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec tFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t


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FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t NEHRP Work shopFEMA Ex is t ing Bui ld ings ATC 71 Pro jec t NEHRP Work shop

Regulatory Highest Priority Needs/Issues

Policies to encourage seismic rehabilitation (Rating System)

Education and training in seismic rehabilitation

Simplified and/or prescriptive procedures

Consistency in Plan Review

Rehabilitation Codes and Standards (consistency in adoptionand enforcement).

Vacant buildings as a result of mandatory retrofit policies



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FEMA Ex is t ing Bui ld ings ATC 71 Pro jec t NEHRP Work shopFEMA Ex is t ing Bui ld ings ATC 71 Pro jec t NEHRP Work shop

Public Policy Issues Strong Support for:

Development of materials to help communities weighseismic risks against other risks.

Advocating that seismic safety is part of greenbuilding and sustainability.



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Public Policy Highest Priority Needs/Issues

Incentives for seismic rehabilitation

Voluntary vs. Mandatory Triggers

Costs for seismic rehabilitation

Social impacts of seismic rehabilitation on vulnerable groups

Public misconception and education on seismic risk



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Research Highest Priority Needs/Issues

Establishment of a coordinated research program forexisting buildings within NEES.

Mitigation of building collapse risks.

Advancement of guidelines and standards- existingbuildings.

Communication of earthquake risks

Calibration of engineering tools with realistic data.

Development of new materials and new building systems.

Development of building investigative technologies



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The Project Management Committee (PMC) lookedat the following issues in context of Seismic

Rehabilitation of Existing Buildings in the U.S.: Current regulatory structure and public/private

policies that define when and how seismic

evaluations and rehabilitation projects areundertaken

Current structural engineering practice involving

existing buildings The available technical resources that can be used by

structural engineers to perform seismic evaluations

and rehabilitations

FEMA Ex is t ing Bui ld ings ATC 71 Pro jec t St at us Report FEMA Ex is t ing Bui ld ings ATC 71 Pro jec t St at us Repor t



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FEMA Ex is t ing Bui ld ings ATC 71 Pro jec t St at us Report

g g jSt at us Report

Policy and Regulation Generally the result of experience with past earthquakes

California Long Beach, 1933 Outlawed URM construction Los Angeles- retrofit ordinance for Tilt-Ups in 1994, (Northridge)

Much variation across the country and across jurisdictions

within States

Mandatory programs California URM law (SB 547)

California SB 1953 Hospitals (State Legislation) City of Berkeley, (Soft Story Ordinance City of Los Angeles, (Tilt Up Ordinance)

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t


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st g u d gs C ojec tSt at us Report


Policy and Regulation

Triggered Rehabilitation

Change of occupancy/use or majoraddition

Most common trigger

current code

AlterationsNot as common, but used in some

jurisdictions

- Los Angeles, San Francisco, Seattle,

PortlandGenerally use value of permitted

work, or square footage

Repair of Substantial Damage



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Voluntary Rehabilitation Policies

Building Officials will permit this work as long as building is no lessconforming when the work is complete.

Without specific criteria, design and construction quality assurancebecomes unclear.

Some jurisdictions refer to model code provisions (IEBC, IBC) to guidevoluntary work.

City of Los Angeles, (wood frame cripple walls, soft stories, hillsidebuildings and certain reinforced concrete and reinforced masonrybuildings.



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Impediments to implementation of regulation

Economic/Market forces -- Cost $$$

Additional code requirements imposed on owners

Lack of knowledge and understanding of the risk

Dont want to know Liability concerns



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g g jSt at us Report St at us Report

Policy and Regulation -Opportunities

Building sustainability (Green)movement

Importance of Historic Preservation

Post 9/11 and Katrina Awarenessof the Importance of CommunityResiliency

Importance of protecting vulnerablecitizens

Media attention on disasters andtheir impacts



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g g jSt at us Report St at us Report

Engineering Practice and Existing Buildings

Nature/Extent of Current Rehabilitation Work

Projects range from a minor strengthening and nonstructural tobringing building into compliance current new code requirements

Commonly part of broader improvement strategy for existing

facility (change in occupancy, bldg addition, re-use, renovation) Project scope is frequently influenced by:

the nature of the triggering-mechanism for the rehabilitation,

the local jurisdictional mandates

real or perceived economic value/benefits for the rehabilitation.

Extent of voluntary seismic rehabilitations varies substantially

Very few projects in regions of low seismicity

A little more common in higher seismic areas.



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St at us Report St at us Report


Regional Variation - West

Coast/Intermountain West - California Majority of seismic rehab projects are

upgrades triggered by changes inuse/occupancy

Many mandated rehab programs in CA haveproduced a large number of projects inclURMs, and parapet bracing in Los Angelesand San Francisco

Some jurisdictions require compliance with theCalifornia Building Code but are unwilling toconsider other approaches such as ASCE 41

because theyre not referenced in CA Code

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t S R


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Regional Variation - West Coast/Intermountain West Washington: Seismic design has long history in the seismically

active region around Seattle, Washington after large seismicevents in the 1940s. Practitioners report more frequent use ofresources such as ASCE 31 and ASCE 41 (or FEMA 356) asacceptable alternative rational engineering approaches permittedby building officials enforcing the Code. Practitioners

Oregon: and the metropolitan area around Portland, have amuch more recent understanding of seismic risk gained in the1980s. Portland practitioners experiences are similar to those inSeattle with respect to use of ASCE 31 and ASCE 41

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t S RFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St t R t


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Engineering Practice and ExistingBuildings

West Coast/Intermountain West -Utah

Like Oregon Seismic risk in Salt LakeCity and the potential effects of theWasatch Fault discovered more recentlythan California and Seattle.

Large stock of URMs includingresidential

Utah Parapet Ordinance (URMs)

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t S RFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St t R t


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Midwest No experience with major earthquakes (New Madrid, 1811)

Seismic design has not been a significant consideration -

practitioners in the region report that there is strong reluctance toacknowledge the potential seismic risk.

Many practitioners today do not consider earthquake shaking tobe a significant

Some voluntary rehabilitation occurs on a voluntary basis forindustrial facilities and hospitals work generally driven by

concerns about Business Continuity

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St t R tFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St t R t


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East Coast The eastern U.S. possesses the oldest building inventory in U.S.,

much of which was constructed without consideration of seismicdesign

Generally (with exception of Charleston, SC) most of the eastcoast seismicity is low to moderate

Where seismic rehabilitation does occur, it is largely triggered by

changes in use and occupancy in a building renovation oraddition and is met with significant resistance

Some voluntary rehabilitation occurs on a voluntary basis work

generally driven by concerns about Business Continuity.

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St t R tFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St at us Report


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Available Technical Resources - Two Broad

Themes Despite the availability of resources targeted toexisting buildings, building codes continue to

trigger and regulate seismic work with reference toinappropriate provisions for new construction

Need to create interest in seismic performancebeyond mere safety including damage control,business continuity, and community resilience weare not there yet

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St at s ReportFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St at us Report


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Impediments to Seismic Evaluation and

Rehabilitation(Engineering perspective):

Lack of building specific loss estimation procedures

Difficult/ineffective communication betweenengineers and owners and stakeholders aboutseismic rehabilitation (Owners Manual).

Seismic standards limit engineering judgment Lack of Business Continuity Guidelines

Inconsistent code enforcement

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St at us ReportFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t St at us Report


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Impediments to Seismic Evaluation andRehabilitation:

Limited training access/opportunities in SeismicRehabilitation

Lack of acceptance of incremental mitigation

strategies for seismic rehabilitation Inconsistencies in the evaluation and rehabilitation of

Nonstructural components

Simplified and/or Prescriptive Procedures in currentstandards are inadequate

Lack of Policies/Guidelines for the SeismicRehabilitation of Historic Buildings



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FEMA Existing Buildings - ATC 71 Project

Status Report

REGION

Method of

Initiation

WEST MIDWEST EAST

Mandatory Medium Low Very Low

Triggered Good Medium Medium

Voluntary Excellent Good Low

Potential Strategies:



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Potential Strategies

In general, plans or programs that rely on voluntaryevaluations and rehabilitations have the greatest potentialif they are effective in communicating seismic risk inmarket terms.

Programs with the next highest potential for success arethose that are triggered by building regulations.

Resistance will be greatest to Mandatory programs,

especially where there hasnt been experience withearthquakes.

FEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t Ac t ion ReportFEMA Ex is t ing Bui ld ings - ATC 71 Pro jec t Ac t ion Report


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Ac t ion Report Ac t ion Report

Where should we go next?

Compile results of Workshop and Status ReportFindings

Analyze what types of projects are most feasible and

will have the largest impact on the needs andpriorities as expressed by the stakeholdercommunity.

Determine how FEMA can best leverage resourcesand partnerships to accomplish the goals.

FEMA Ex ist ing Bui l d ings Program Fina l Thought sFEMA Ex ist ing Bui ld ings Program Fina l Thought s


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Final Thought s Fina l Thought s

Progress made but theres a long way to go

How do we motivate action based on more thangood science?

Creative solutions that resonate are needed

Frame the issues in terms people understand andrelate to economically and emotionally as well as

technically


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assessment existing building,laatsch

Documents