1、Designation:D440320Standard Practice forExtensometers Used in Rock1This standard is issued under the fixed designation D4403;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates
2、the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers the description,application,selection,installation,data collecting,and data reduction of thevarious types of contact type extensometers used in the f
3、ield ofrock mechanics.Laser or other non-contact extensometers arenot covered here.1.2Limitations of each type of extensometer system arecovered in Section 5.1.3 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are mathemati-cal conversions to S
4、I units that are provided for informationonly and are not considered standard.Add if appropriate,“Reporting of test results in units other than inch-pound shallnot be regarded as nonconformance with this standard.1.4 All observed and calculated values shall conform to theguidelines for significant d
5、igits and rounding established inPractice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used
6、 do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ations for the users objectives;and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations.It is beyond the scopeof this stand
7、ard to consider significant digits used in analysismethods for engineering design.1.5 The text of this standard references notes and footnoteswhich provide explanatory material.These notes and footnotes(excluding those in tables and figures)shall not be consideredas requirements of the standard.1.6
8、This practice offers a set of instructions for performingone or more specific operations.This document cannot replaceeducation or experience and should be used in conjunctionwith professional judgment.Not all aspects of this guide maybe applicable in all circumstances.This ASTM standard is notintend
9、ed to represent or replace the standard of care by whichthe adequacy of a given professional service must be judged,nor should this document be applied without consideration ofa projects many unique aspects.The word“Standard”in thetitle of this document means only that the document has beenapproved
10、through the ASTM consensus process.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regul
11、atory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Org
12、anization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and Constructi
13、onD6026 Practice for Using Significant Digits in GeotechnicalData3.Terminology3.1 DefinitionsTerms not defined below may appear inTerminology D653.4.Significance and Use4.1 Extensometers are widely used in the field of engineer-ing and include most devices used to measure displacements,separation,se
14、ttlements,convergence,and the like.1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.23 on Field Instrumen-tation.Current edition approved Jan.1,2020.Published March 2020.Originallyapproved in 1984.Last previous editio
15、n approved in 2012 as D440312.DOI:10.1520/D4403-20.2For 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.*A Summary of C
16、hanges section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.4.2 For tunnel instrumentati
