1、Designation: E2557 16a An American National StandardStandard Practice forProbable Maximum Loss (PML) Evaluations for EarthquakeDue-Diligence Assessments1,2This standard is issued under the fixed designation E2557; the number immediately following the designation indicates the year oforiginal adoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice establishes standard-of-care for evaluationand classification
3、 of the financial risks from earthquake dam-age to real estate improvements for use in financial mortgagetransactions and capital investment evaluation. As such, thispractice permits a user to satisfy, in part, their real estatetransaction due-diligence requirements with respect to assess-ing and ch
4、aracterizing a propertys potential losses fromearthquakes. This practice is intended to address only physicaldamage to the property from site and building response.1.1.1 Hazards addressed in this practice include earthquakeground shaking, earthquake-caused site instability, includingfaulting, subsid
5、ence, settlement landslides and soilliquefaction, earthquake-caused tsunamis and seiches, andearthquake-caused flooding from dam or dike failures.1.1.2 Earthquake-caused fires and toxic materials releasesare not hazards considered in this practice.1.1.3 This practice does not purport to provide for
6、thepreservation of life safety, or prevention of building damageassociated with its use, or both.1.1.3.1 This practice does not address requirements of anyfederal, state, or local laws and regulations of building con-struction or maintenance. Users are cautioned that currentfederal, state, and local
7、 laws and regulations may differ fromthose in effect at the times of construction or modification ofthe building(s), or both.1.1.3.2 This practice does not address the contractual andlegal obligations between prior and subsequent Users ofseismic risk assessment reports or between providers whoprepar
8、ed the report and those who would like to use such priorreports.1.1.3.3 This practice does not address the contractual andlegal obligations between a provider and a user, and otherparties, if any.1.1.4 It is the responsibility of the owner of the building(s)to establish appropriate life-safety and d
9、amage preventionpractices and determine the applicability of current regulatorylimitations prior to use.1.2 Considerations not included in the scope: the impacts ofdamage to contents, loss of income(s), rents, or other economicbenefits of use of the property, or from legal judgments, firesprinkler w
10、ater-induced damage or fire.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2. Referenced Documents2.1 ASTM Standards:3E2026 Guide fo
11、r Seismic Risk Assessment of Buildings2.2 Other Standards:4UBC-97 Uniform Building Code, 1997 EditionIBC International Building Code, current edition2.3 ASCE Standards:5ASCE 7 Minimum Design Loads for Buildings and OtherStructures, current editionASCE 41 Seismic Evaluation and Retrofit of ExistingBu
12、ildings, current edition3. Terminology3.1 See also definitions in Guide E2026.3.2 475-year site ground motions, nseismic inducedground motions at a site with approximately: a return period of475 years, a 10 % probability of exceedance in 50 years, and anannual frequency of 0.21 %. Also referred to a
13、s the DBE.3.3 field assessor, nfield assessor, as defined in GuideE2026.1This practice is under the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.25 onWhole Buildings and Facilities.Current edition approved May 15, 2016. Publishe
14、d June 2016. Originallyapproved in 2007. Last previous edition approved in 2016 as E2557-16. DOI:10.1520/E2557-16A.2Portions of this publication reproduce content from the 1997 Uniform BuildingCode, International Code Council, Inc., Falls Church, Virginia. Reproduced withpermission. All rights reser
15、ved.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from International Code Council (ICC), 500 New
16、 Jersey Ave., NW,6th Floor, Washington, DC 20001, http:/www.iccsafe.org.5Available from American Society of Civil Engineers (ASCE), 1801 AlexanderBell Dr., Reston, VA 20191, http:/www.asce.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United
17、States13.4 independent reviewer, nindependent reviewer, as de-fined in Guide E2026.3.5 lateral load-resisting system, nlateral load-resistingsystem, as defined in Guide E2026.3.6 MCE, nMaximum Capable Earthquake, as defined inGuide E2026.3.7 probable loss (PL), nprobable loss, as defined inGuide E20
18、26.3.7.1 DiscussionWhen there are multiple buildings in theseismic risk assessment, then the damageability values for thegroup of buildings is to be determined as specified in GuideE2026.3.8 probable maximum loss (PML), nprobable maximumloss, as defined in Guide E2026.3.9 provider, nprovider, as def
19、ined in Guide E2026.3.10 scenario expected loss (SEL), nscenario expectedloss, as defined in Guide E2026.3.10.1 DiscussionWhen there are multiple buildings inthe assessment then the SEL for the group of buildings is to bedetermined as specified in Guide E2026, Section 5.3.3.11 scenario loss (SL), ns
20、cenario loss, as defined inGuide E2026.3.11.1 DiscussionWhen multiple buildings are in the seis-mic risk assessment, then the SL for the group of buildings isto be determined as specified in Guide E2026, Section 5.3.3.12 scenario upper loss (SUL), nscenario upper loss, asdefined in Guide E2026.3.12.
21、1 DiscussionWhen there are multiple buildings inthe assessment then the SUL for the group of buildings is to bedetermined as specified in Guide E2026, Section 5.3.3.13 SEL475, nthe scenario expected loss due to theoccurrence of 10 %/50-year site ground motions.3.14 SELMCE,nthe scenario expected loss
22、 due to theoccurrence of MCE site ground motions.3.15 senior assessor, nsenior assessor, as defined in GuideE2026.3.16 significant damage, nsignificant damage, as definedin Guide E20263.17 SUL475, nthe scenario upper loss due to the occur-rence of 10 %/50-year site ground motions.3.18 SULMCE,nthe sc
23、enario upper loss due to the occur-rence of MCE site ground motions.4. Summary of Practice4.1 The objectives of this practice are as follows:4.1.1 To synthesize and document good commercial prac-tice for the determination and rating of seismic risk forbuildings.4.1.2 To facilitate standardization of
24、 earthquake risk evalu-ation terminology for financial transactions.4.1.3 To establish an industry standard for the requirementsto evaluate the financial risk for real estate.5. Significance and Use5.1 This practice is intended for use as a voluntary standardby parties who wish to undertake the seis
25、mic risk assessment ofproperties. The goal is for users to objectively and reliablycompare the financial risks of earthquake damage to buildings,or groups of buildings, on a consistent basis.5.2 This practice is designed to provide requirements for theevaluation of earthquake damage risk so that tec
26、hnical reportsprepared for the evaluation and rating of seismic risk of abuilding(s) will be adequate for use by other entities. Potentialusers including, but are not be limited to, those making equityinvestments, lending, and financial transactions, includingsecuritized mortgage lending by mortgage
27、 originators, loanservicers, underwriters, rating agencies, and purchasers ofbonds secured by the real estate.5.3 The use of this practice may permit a user to satisfy, inpart, their requirements for due diligence in assessing apropertys potential for losses associated with earthquakes forreal estat
28、e transactions.6. Due-Diligence Investigation6.1 The site stability, building stability and building dam-ageability of the property shall be assessed.6.2 The user shall specify the condition of the property to beevaluated. The seismic performance can be evaluated for theproperty in its current condi
29、tion, or as changed by proposedmodification of the seismic response of the soils supporting thebuilding or a proposed seismically retrofitted condition of thebuilding(s) or its sections, or any combination of these condi-tions.6.2.1 The proposed seismic modifications of the site mustbe sufficiently
30、described to allow evaluation of the modifica-tions by an Independent Reviewer.6.2.2 The proposed seismic modifications of the buildingsystems must be sufficiently described to allow evaluation ofthe modifications by an Independent Reviewer.6.3 The Guide E2026 level of investigation shall be speci-f
31、ied by the user. The same level of investigation should beperformed for each type of the seismic risk assessment.Appendix X2 gives guidance on the setting of the level ofinvestigation.6.4 The qualifications of the Provider shall be specified asrequired for the level of investigation specified in 6.3
32、 of GuideE2026. The qualifications level must be equal to or higher thanthe corresponding level specified in 6.2 and 6.3. Appendix X1gives further guidance on the setting of minimum qualifica-tions.6.4.1 For an assessment of Level 1 or higher, the qualifica-tions of Senior Assessor and the Field Ass
33、essor of the propertyand its buildings shall be those of Guide E2026 Sections6.2.3.2 and 6.2.3.3.6.4.2 Notwithstanding the asserted level of investigation ofa report, if the Senior Assessor or the Field Assessor, or both,do not demonstrate the qualifications of Guide E2026 Section6.2.3.2 and 6.2.3.3
34、, then the report shall be designated a Level0 report.E2557 16a26.5 Seismic Risk Assessment ReportThe findings shall bereported in conformance to the requirements of Guide E2026for the level of investigation specified by the user in 6.3 and bya provider qualified in accordance with the requirements
35、of 6.4,with the following sections:6.5.1 A summary that contains the conclusions of theseismic risk assessment:6.5.1.1 Location of the building(s), characterization of thesite and site soils, and gravity and lateral load-resistingsystems.6.5.1.2 Stability determination of each building site undercon
36、sideration when subjected to the seismic loadings for thebuilding site location and building characteristics as set forth inSection 9 of Guide E2026. Site stability determination needonly be qualitative in nature for an SS0 investigation. For SS1investigations the site stability is a qualitative ass
37、essment thatincludes the implications on damage to the building structuralelements. For SS2 and SS3 investigations the site should beconsidered unstable if significant damage is caused to thebuilding by the site instability.6.5.1.3 Stability determination of each building under con-sideration in the
38、 seismic loadings for the building site locationand building characteristics and for the level of investigationspecified, as set forth in Section 8 of Guide E2026.6.5.1.4 The building damageability values for the buildingor group of buildings as a whole for the level of investigationspecified as set
39、 forth in Section 10 of Guide E2026.(1) PML shall be user-defined. At a minimum, the SELDBEand SULDBEshall be reported.NOTE 1CMBS industry is currently defining PML as SELDBE.Itisadvisable that SEL and SUL values also be reported for MCE events inareas of low and moderate seismicity areas where MCE
40、poses significantlyhigher risk than the DBE.6.5.1.5 A specification of the level of investigation for eachassessment and a review of the methods used and the personnelengaged.6.5.1.6 Results for each of the conditions described in 6.2that apply.6.5.1.7 Appropriate reliance language for the report an
41、dsignature. For Level 1 or higher investigations, the professionalseal of the provider.6.5.1.8 All deletions and deviations from this practice (ifany) shall be listed individually and in detail.6.5.1.9 The report conclusion shall include the followingstatement: “We have performed a probable maximum
42、loss(PML) evaluation for earthquake due diligence assessment inconformance with the scope and limitations of Guide E2026and Practice E2557 for a Level XX (specify) assessment ofinsert address or legal description, the property. Any excep-tions to, or deletions from, this practice are described inSec
43、tionofthis report. This probable maximum loss (PML)evaluation for earthquake due diligence assessment has deter-mined the PML to be %.” PML is defined as fill in thedefinition used. The project meets/does not meet the build-ing stability and meets/does not meet the site stabilityrequirements.6.5.1.1
44、0 Each report should include a completed AppendixX4.6.5.1.11 Each report should include a completed AppendixX5.6.5.2 A body of the report that provides:6.5.2.1 All detailed reporting information required by GuideE2026, Section 13, including the basis and background for thework performed in support o
45、f the conclusions presented in thereport.6.5.2.2 PML values for each building, and, if appropriate,for the group of buildings.(1) Report of any other information required by the user,which may include business interruption, and contents dam-ageability.(2) The organization that commissioned the repor
46、t and theprofessional liability limitations of the report provider shall bedisclosed in the report.6.5.3 Attachments and appendices to the report as appropri-ate including detailed resumes of the Senior Assessor and theField Assessor that demonstrate their qualifications to performthis work as state
47、d in this Practice.E2557 16a3APPENDIXES(Nonmandatory Information)X1. GUIDANCE FOR USE OF E2557INTRODUCTIONThis Appendix provides guidance to decision makers for sorting their way through the intricaciesof seismic risk assessment. Usually a due-diligence financial decision is posed as should thetrans
48、action be considered further or not? A PML assessment is commissioned to understand if thereis a seismic hazard at the property and the extent of the risk it poses. The process used to completePML assessments should consider the various sources of uncertainty as well as the financial and otherconseq
49、uences that may arise when a good building is called bad (Type I error), or when a badbuilding is called good (Type II error). An error of the first type precludes a possibly profitableinvestment but otherwise is benign in that it does not lead to a loss, whereas the latter error has a higherrisk than is nominally acceptable and may lead to large loss. Type II errors lead to unexpectedly higherrisks and should be minimized consistent with other objectives of the User. Experience of the ASTMCommittee members suggests that the likelihood of
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