ASTM D6825-2014 9436 Standard Guide for Placement of Riprap Revetments《抛石护坡堆放的标准指南》.pdf

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1、Designation: D6825 14Standard Guide forPlacement of Riprap Revetments1This standard is issued under the fixed designation D6825; 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 ind

2、icates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This guide covers methods to place riprap with associ-ated filters for erosion control purposes. This guide does notrecommend a specific course of action becau

3、se of the diversemethods and procedures that are capable of producing afunctional product. This guide identifies favorable riprap quali-ties and recommends practices best suited to obtain thosequalities. The production of rock, use of recycled materials,rock with cut dimensions, and engineering and

4、revetmentdesign are beyond the scope of this guide. Special forms ofriprap, including hand placed riprap, grouted riprap, or keyed(plated) riprap that is tamped into place to smooth the surface,are also beyond the scope of this guide.1.2 This guide offers an organized collection of informationor a s

5、eries of options and does not recommend a specific courseof action. This document cannot replace education or experi-ence and should be used in conjunction with professionaljudgment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intended to repre-sent

6、 or replace the standard of care by which the adequacy ofa given professional service must be judged, nor should thisdocument be applied without consideration of a projects manyunique aspects. The word “Standard” in the title of thisdocument means only that the document has been developedand approve

7、d through the ASTM consensus process1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.4 This standard may involve hazardous operati

8、ons andequipment. 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 requirements prior to use.

9、2. Referenced Documents2.1 ASTM Standards:2C33 Specification for Concrete AggregatesC136 Test Method for Sieve Analysis of Fine and CoarseAggregatesD75 Practice for Sampling AggregatesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD4992 Practice for Evaluation of Rock to be Used forEros

10、ion ControlD5519 Test Methods for Particle Size Analysis of Naturaland Man-Made Riprap MaterialsD6092 Practice for Specifying Standard Sizes of Stone forErosion Control2.2 AASHTO Standard:3M 288 Geotextile Specification for Highway Applications3. Terminology3.1 DefinitionsSee Terminology D653 for ge

11、neral defini-tions.3.2 Definitions of Terms Specific to This Standard:3.2.1 beddingan aggregate mixture placed below the rip-rap. Bedding material is usually sand and gravel sized, but mayinclude cobble sized material. If placed without a geotextile,the bedding material may be used as a filter. If p

12、laced inconjunction with a geotextile, the bedding may provide acushion for protection of the geotextile during riprap placementand provide confinement of the geotextile. It is possible to havemore than one bedding layer.3.2.2 chinkingthe practice of filling riprap surface voidswith smaller sized ro

13、ck or aggregate.3.2.3 clam shella bucket tool that is operated from adragline or crane. The bucket is hinged at the top and openslike a clam so that rock can be placed without dropping it.3.2.4 Dxthe particle diameter at which x % by weight(dry) of the particles of a particular sample are finer.1Thi

14、s guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.17 on Rock for ErosionControl.Current edition approved Feb. 1, 2014. Published March 2014. Originallyapproved in 2002. Last previous edition approved in 2008 as D6825 02 (Reap-

15、proved 2008)1. DOI: 10.1520/D6825-14.2For 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.3Available from American

16、 Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocke

17、n, PA 19428-2959. United States13.2.5 filterany substance, as geotextile or layer of sand/aggregate, placed to provide separation and retention ofmaterials, while allowing water to pass.3.2.6 floatera individual rock within the riprap layer thatis not interlocked with the surrounding rocks.3.2.7 max

18、imum aspect ratiothe ratio of the greatest to theleast dimension, measured across mutually perpendicular axes,for any piece of rock; synonym, slabbiness.3.2.8 orange peela bucket tool that is operated from adragline or crane and resembles the shape of an orange peeling.The sides lift up and out so t

19、hat rock can be placed withoutdropping it.3.2.9 pit run materialrock that has been blasted but notprocessed to remove undersize pieces; synonym, shot rock orquarry run.3.2.10 revetmentbank protection by armor, that is, byfacing of a bank or embankment with erosion-resistant mate-rial.3.2.11 riprapma

20、terial generally less than 2 tons (1.8tonnes) in mass, specially selected and graded. When properlyplaced, riprap prevents erosion through minor wave action, orstrong currents and thereby preserves the shape of a surface,slope, or underlying structure. Riprap may be specificallyproduced for the inte

21、nded purpose, or it may be a by-productfrom a mining operation, structure demolition, or industrialprocess.3.2.12 rockany naturally formed aggregate of mineralmatter occurring in large masses or fragments. Rock may beeither insitu or excavated material.4. Significance and Use4.1 Riprap is a commonly

22、 used form of scour protection andgeneral slope protection. Riprap provides a long term solutionwhen properly sized and installed. Riprap has structural flex-ibility so it will conform to irregular surfaces and adapt tominor subgrade settlement. It is often appropriate for use inconjunction with soi

23、l bioengineering (vegetation establish-ment) alternatives. In some environments, riprap may providehabitat for benthic organisms and fish.4.2 Revetments provide a facing or lining to armor asurface; and the layer thickness is typically minimized whileproviding the necessary resistance to scour. In t

24、his case,standardized practices to obtain consistent coverage havingacceptable thickness tolerances and voids become important.4.3 This guide may be used by owners, installationcontractors, regulatory agencies, inspection organizations, anddesigners and specifiers who are involved in the constructio

25、n ofriprap revetments. Modifications may be required for specificjob conditions. This guide is not intended for constructionspecifications on large projects, but may be referenced wherepreparation of job specific construction specifications are notjustified. If this practice is included by reference

26、 in contractdocuments, the specifier must provide a list of supplementalrequirements.5. Planning for Riprap Placement5.1 Site conditions, level of protection required, construc-tion methods, and equipment may affect the sizing, thickness,and lateral extent of a riprap revetment. For some smallprojec

27、ts, riprap may be dumped with minimal analysis orquality control, and still fulfill the intended purpose. For largerprojects and critical structures, engineering, careful placement,and quality control become increasingly justified to minimizematerial costs and reduce the chance of failure. The degre

28、e ofcontrol appropriate should be appropriate for each project. Themethods for placement and quality control should be compat-ible with the level of site investigation and other considerationsincluded in Table 1. Table 1 includes factors which should beconsidered, but are beyond the scope of this gu

29、ide. Somerecommended publications (1-7)4from the Army Corps ofEngineers and the Federal Highway Administration for addi-tional information on these factors and engineering criteria aregiven in the References section.NOTE 1Slope stability should always be considered. If it is notinvestigated analytic

30、ally by a qualified professional, then it should at leastbe considered subjectively in light of the site conditions and surroundingconditions (riverbanks, shorelines, or landforms). Many agencies havegeneralized maximum allowable slopes (usually in the range of 1.5H:1Vto 3H:1V); however, these must

31、be recognized as site specific. Limitationsof the foundation, bank, material interfaces, seepage conditions, or toescour may lead to instability.6. Riprap Materials6.1 Stone Sources and EvaluationRock must be durablematerial. In some cases, a source may be established based onrock classification, ge

32、ologic evaluation, and observations ofexisting installations showing that the rock is durable. If ahistory of rock durability is not established, sampling andtesting the rock may be required. Acceptable material proper-ties for rock are dependent on the conditions (such as abrasionand saturation fre

33、quency due to wave run-up) and climate inthe vicinity of where it will be used. Source selection must alsoconsider the material properties available from local sources.Riprap is most commonly produced at a quarry, but it may alsobe screened from a gravel pit operation, processed from rockcollected f

34、rom some other source, or manufactured fromcrushed hydraulic-cement (recycled) concrete.NOTE 2Borrowing stone, cobbles or gravel from stream or lake bedsthat do not otherwise need to be disturbed may have environmentalconsequences and may not be allowed under state and federal permits.6.1.1 Sampling

35、 and Testing Rock SourcesPractice D4992provides guidance on sampling a source rock. Acceptancecriteria, as outlined in EM 1110-2-2302 (1), should be consid-ered. Also consider characteristics of rock found in nearbyquarries. Information provided with rock samples shouldinclude the location from whic

36、h the sample was taken, and thestratigraphy for samples obtained at quarries. (See Note 3).NOTE 3Due to the relative cost of producing and transporting riprapin relation to placing it at the site, there is a potential for disputes wheresampling and testing at the source have implied acceptance of th

37、e materialand the Owner later rejects the material at the placement site. Contract4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.D6825 142specifications should clearly state where the riprap will be sampled fortesting and what constitutes final acceptan

38、ce of the material.6.2 Riprap GradingRecommended gradation require-ments for processed riprap are given in Practice D6092. Thegradations are considered to be optimum size variationsconsidering rock stability, riprap voids affecting filtration of thesubgrade, and typical quarry processing capabilitie

39、s. Researchat the Corps of Engineers Waterways Experiment Station in the1960s and 1970s confirmed that there is an optimum sizevariation for riprap stability. Riprap layers consisting of un-form size rocks have a rougher surface to hydraulic flowgenerating greater tractive shear stress, which may le

40、ad toinstability. The voids in a well graded riprap mix are partiallyfilled with smaller rocks, resulting in a smoother surface andlower tractive shear stress. Material that is too broad in gradingis susceptible to segregation and loss of the small stones.6.2.1 Sampling and Testing Material Gradatio

41、nsThe rip-rap grading should be verified. When gradation tolerances arecritical, the grading should be determined in accordance withTest Methods D5519. Riprap samples should be taken fromstockpiles, loaded trucks or in place test plots. Bedding andfilter materials should be sampled in accordance wit

42、h PracticeD75 and tested in accordance with Test Method C136.NOTE 4Due to the economical limitations of obtaining the numberand size of samples to be statistically meaningful, the Owner andContractor should have a partnering relationship. Both parties shouldmake an effort to be present during rock s

43、ource sampling and field testing.6.2.2 Pit run material, rather than processed rock, is oftenused due to its lower cost, greater availability, and broadergrading. For similar rock stability and filtration characteristics,pit run material must be placed in greater thickness and stonesize than process

44、ed riprap.6.3 Recycled MaterialsRecycled materials may be usedfor sustainable design and development. However, qualityassurance of recycled material is generally more difficult tomonitor when compared to the quality assurance of naturalmaterials. The material must be appropriate for the intendeduse.

45、 Crushed hydraulic-cement concrete may be obtained fromvarious sources with inconsistent strength and durability. Slabsin the source material and the amount of reinforcing steel cancomplicate control of the grading requirements and the aspectratio of individual stones.7. Filter Materials7.1 Purpose

46、of FiltersFor revetments placed as thin fac-ings or linings, a filter is required to prevent loss of thesubgrade by turbulent flow through the voids in the riprap.Filters for riprap consist of bedding or geotextiles. Filters areselected to provide soil retention and adequate permeability forsubgrade

47、 drainage. This requires balancing two opposingcriteria: the opening sizes (voids) must be small enough toretain the subgrade particles and large enough to provideadequate permeability for water passage. In some cases,multiple layers may be required.7.2 BeddingBedding material should be composed oft

48、ough, durable particles, free from thin, flat and elongatedpieces, and should contain minimal quantities of organic matterand soft friable particles.Aggregates should generally meet thequality requirements of Specification C33. Some typical gra-dation requirements for bedding materials are given in

49、PracticeD6092. It is sometimes more economical to specify a com-monly produced gradation, such as a state transportationdepartment gradation for concrete or bituminous aggregate. ItTABLE 1 Predominant Factors for Placement and Maintenance of RiprapFactorSiteConditionDesignControlConstructionControlPostConstructionControlHydraulic bed shear stressFlow velocity or wave amplitudeFlow turbulenceFlow depth or wave run-upWater density (salinity)X- - -Debris impact and ice action X - - XBed slope, side slopes (hydraulic stability) X X - -Slope Stability (se