1、Designation:D812221Standard Test Method forDetermining Mass per Unit Area of Geohazard Nettings1This standard is issued under the fixed designation D8122;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A num
2、ber in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is an index test to determine the massper unit area of geohazard nettings.The mass per unit area isa characteristic of a geoh
3、azard netting that contributes to itsability to stabilize and control the movement of loose rocks.There are many different types of geohazard nettings whichnecessitates a single standard by which all geohazard nettingsmay be measured.1.2 UnitsThe values stated in SI units are to be regardedas standa
4、rd.The values given in parentheses are provided forinformation only and are not considered standard.Reporting oftest results in units other than SI shall not be regarded asnonconformance with this standard.1.2.1 It is common practice in the engineering/constructionprofession to concurrently use poun
5、ds to represent both a unitof mass(lbm)and of force(lbf).This practice implicitlycombines two separate systems of units;the absolute and thegravitational systems.It is scientifically undesirable to com-bine the use of two separate sets of inch-pound units within asingle standard.As stated,this stand
6、ard includes the gravita-tional system of inch-pound units and does not use/present theslug unit of mass.However,the use of balances and scalesrecording pounds of mass(lbm)or recording density in lbm/ft3shall not be regarded as nonconformance with this standard.1.2.2 The terms density and unit weigh
7、t are often usedinterchangeably.Density is mass per unit volume,whereas,unit weight is force per unit volume.In this standard,densityis given only in SI units.After the density has been determined,the unit weight is calculated in SI or inch-pound units,or both.1.3 All observed and calculated values
8、shall conform to theguidelines for significant digits and rounding established inPractice D6026,unless superseded by this test method.1.3.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as theindustry standard.In addition,they are represen
9、tative of thesignificant digits that generally should be retained.The proce-dures used 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 reporte
10、d data to becommensurate with these considerations.It is beyond the scopeof these test methods to consider significant digits used inanalysis methods for engineering data.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of
11、 the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization establish
12、ed in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD3740 Practic
13、e for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4230 Test Method for Measuring Humidity with Cooled-Surface Condensation(Dew-Point)HygrometerD4753 Guide for Evaluating,Selecting,and Specifying Bal-ances and St
14、andard Masses for Use in Soil,Rock,andConstruction Materials TestingD6026 Practice for Using Significant Digits and Data Re-cords in Geotechnical Data3.Terminology3.1 Definitions:3.1.1 For definitions of common technical terms used in thisstandard,refer to Terminology D653.3.2 Definitions of Terms S
15、pecific to This Standard:1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.25 on Erosion andSediment Control Technology.Current edition approved Sept.1,2021.Published September 2021.DOI:10.1520/D8122-212For reference
16、d 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.Copyright 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 theDevel