1、Designation:D482395(Reapproved 2014)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 revisio
2、n.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
3、 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
4、 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 co
5、resampling 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 andpropor
6、tions.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 guid
7、e.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
8、.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 and health practices and determine the applica-bility of regulatory limitations prior to use.For specificwarning
9、 statements,see 6.3 and 11.5.2.Referenced Documents2.1 ASTM Standards:2D420 Guide to Site Characterization for Engineering Designand Construction Purposes(Withdrawn 2011)3D1129 Terminology Relating to WaterD1452 Practice for Soil Exploration and Sampling by AugerBoringsD1586 Test Method for Penetrat
10、ion Test(SPT)and Split-Barrel Sampling of SoilsD1587 Practice for Thin-Walled Tube Sampling of Soils forGeotechnical PurposesD4220 Practices for Preserving and Transporting SoilSamplesD4410 Terminology for Fluvial Sediment3.Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer
11、to Terminology D1129 and Terminology D4410.3.2 Definitions of Terms Specific to This Standard:3.2.1 check valvea device(see Fig.1)4mounted 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 downw
12、ard motion stops,thevalve closes.During retrieval,the valve remains closed andcreates suction that holds the core inside the barrel.3.2.2 corea vertical column of sediment cut from a parentdeposit.3.2.3 core catchera device(see Fig.2)that grips andsupports the core while the sampler is being pulled
13、from thesediment and hoisted to the water surface.3.2.4 core conveyora device(see Fig.3)for reducingfriction between a core and the inside surface of a core barrel.3.2.5 core-barrel linera rigid,thin-wall tube mountedinside the barrel of a core sampler.During the core-cuttingprocess,sediment moves u
14、p inside the liner.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 Jan.1,2014.Published March 2014.Originallyapproved in 1988.Last previous edition ap
15、proved in 2008 as D4823 95(2008).DOI:10.1520/D4823-95R14.2For 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 last
16、 approved version of this historical standard is referenced onwww.astm.org.4The boldface numbers in parentheses refer to the list of references at the end ofthis guide.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.6 core sampleran instrument for collecting cores.3.2.7 extrudeThe act of pushing a core from a core barrelor a core-barrel liner.3.2.8open-barrel samplerin simplest form,a straighttube open at both ends.More elaborate