ASTM_D_4436_-_13e1.pdf

Designation:D4436131Standard Test Method forRock Bolt Long-Term Load Retention Test1This standard is issued under the fixed designation D4436;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 the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1NOTEEditorial corrections were made throughout in February 2014.1.Scope*1.1 The objective of this test method is to determine thetime over which rock bolt tension decreases from the installedvalue to a designated minimum value.1.2 This test method is applicable to any anchor systemwhich is not fully encapsulated immediately upon installation,including mechanical,cement grout,resin(epoxy,polyester,and the like)or other similar systems.1.3 UnitsThe values stated in inch-pound units are to beregarded as standard.The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.Reporting oftest results in units other than inch-pounds shall not beregarded as nonconformance with this test method.1.3.1 The gravitational system of inch-pound units is usedwhen dealing with inch-pound units.In this system,the pound(lbf)represents a unit of force(weight),while the unit for massis slugs.1.4 All observed and calculated values shall conform to theguidelines for significant digits 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 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 standard to consider significant digits used in analyticalmethods for engineering design.1.5 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 and health practices and determine the applica-bility of regulatory limitations prior to use.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 ConstructionD4435 Test Method for Rock Bolt Anchor Pull TestD6026 Practice for Using Significant Digits in GeotechnicalData3.Terminology3.1 DefinitionsFor definitions of common technical termsin this standard,refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 loadthe total axial force on the rock bolt.3.2.2 design loadthe load specified for the rock boltduring the life of the project.3.2.3 installation loadthe load on the bolt immediatelyafter installation.3.2.4 stand timethe time required for the bolt load todecrease from the installation load to the design load.4.Summary of Test Method4.1 A rock bolt is installed in the same manner and in thesame material as its intended support use.The load on the boltis monitored over a period of time,usually several weeks.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved Nov.1,2013.Published December 2013.Originallyapproved in 1984.Last previous edition approved in 2008 as D4436 08.DOI:10.1520/D4436-13E01.2For 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 Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 Rock bolts are used for support in a variety of miningand civil engineering situations.3After a bolt is installed,theload generally decreases over time due to deterioration of theborehole wall,creep,and other factors.This process may bearrested by fully encapsulating the bolt shortly after installa-tion.This encapsulation is generally done by pumping the bolthole full of cement grout,though synthetic resins may also beused.The rate of load loss determines the interval during whichthe bolt must be encapsulated during construction.5.2 The local characteristics of the rock,such as roughnessof the borehole and induced fractures,are significant factors inthe load loss characteristics of the bolt.To obtain realisticvalues,the test holes sho