ASTM_D_4823_-_95_2019.pdf

Designation:D482395(Reapproved 2019)Standard Guide forCore Sampling Submerged,Unconsolidated Sediments1This standard is issued under the fixed designation D4823;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.1.Scope1.1 This guide covers core-sampling terminology,advan-tages and disadvantages of different types of core samplers,core-distortions that may occur during sampling,techniquesfor detecting and minimizing core distortions,and methods fordissecting and preserving sediment cores.1.2 In this guide,sampling procedures and equipment aredivided into the following categories based on water depth:sampling in depths shallower than 0.5 m,sampling in depthsbetween 0.5 m and 10 m,and sampling in depths exceeding 10m.Each category is divided into two sections:equipment forcollecting short cores and equipment for collecting long cores.1.3 This guide emphasizes general principles.Only in a fewinstances are step-by-step instructions given.Because coresampling is a field-based operation,methods and equipmentmust usually be modified to suit local conditions.This modi-fication process requires two essential ingredients:operatorskill and judgment.Neither can be replaced by written rules.1.4 Drawings of samplers are included to show sizes andproportions.These samplers are offered primarily as examples(or generic representations)of equipment that can be purchasedcommercially or built from plans in technical journals.1.5 This guide is a brief summary of published scientificarticles and engineering reports.These references are listed inthis guide.These documents provide operational details thatare not given in this guide but are nevertheless essential to thesuccessful planning and completion of core sampling projects.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 regulatory limitations prior to use.For specific warning statements,see 6.3 and 11.5.1.8 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 Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D420 Guide for Site Characterization for Engineering De-sign and Construction PurposesD1129 Terminology Relating to WaterD1452 Practice for Soil Exploration and Sampling by AugerBoringsD1586 Test Method for Standard Penetration Test(SPT)andSplit-Barrel Sampling of SoilsD1587 Practice for Thin-Walled Tube Sampling of Fine-Grained Soils for Geotechnical PurposesD4220 Practices for Preserving and Transporting SoilSamplesD4410 Terminology for Fluvial Sediment3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard,refer toTerminologies D1129 and D4410.3.2 Definitions of Terms Specific to This Standard:3.2.1 check valve,na device(see Fig.1)3mounted atop anopen-barrel core sampler.As the sampler moves down throughwater and sediment,the valve remains open to allow water toflow up through the barrel.When downward motion stops,thevalve closes.During retrieval,the valve remains closed andcreates suction that holds the core inside the barrel.3.2.2 core,na vertical column of sediment cut from aparent deposit.1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.07 on Sediments,Geomorphology,and Open-Channel Flow.Current edition approved Nov.1,2019.Published January 2020.Originallyapproved in 1988.Last previous edition approved in 2014 as D4823 95(2014).DOI:10.1520/D4823-95R19.2For 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.3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.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 theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.3.2.3 core catcher,na device(see Fig.2)that grips andsupports the c