1、Designation: D6825 141Standard 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 in
2、dicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorially updated units of measurement statement in April 2018.1. Scope*1.1 This guide covers methods to place riprap with associ-ated filters for erosion control p
3、urposes. This guide does notrecommend a specific course of action because 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, u
4、se of recycled materials,rock with cut dimensions, and engineering and 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 g
5、uide.1.2 This guide offers an organized collection of informationor a series 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 applicabl
6、e in allcircumstances. This ASTM standard is not intended to repre-sent 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
7、thisdocument means only that the document has been developedand approved through the ASTM consensus process1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses after SI units areprovided for information only and are not considered standard.1.4 This standar
8、d may involve hazardous operations 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 regula
9、tory requirements prior to use.1.5 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 Or
10、ganization TechnicalBarriers to Trade (TBT) Committee.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 ContainedFluidsD4
11、992 Practice for Evaluation of Rock to be Used forErosion 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.
12、 Terminology3.1 DefinitionsSee Terminology D653 for general 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 geotext
13、ile,the bedding material may be used as a filter. If placed inconjunction with a geotextile, the bedding may provide acushion for protection of the geotextile during riprap placement1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcomm
14、ittee 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-proved 2008)1. DOI: 10.1520/D6825-14E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orco
15、ntact 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 Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washingt
16、on, 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 Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally rec
17、ognized 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.1and provide confinement of the geotextile. It is possible to h
18、avemore than one bedding layer.3.2.2 chinkingthe practice of filling riprap surface voidswith smaller sized rock 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.
19、2.4 Dxthe particle diameter at which x % by weight(dry) of the particles of a particular sample are finer.3.2.5 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 th
20、e riprap layer thatis not interlocked with the surrounding rocks.3.2.7 maximum 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 a
21、nd resembles the shape of an orange peeling.The sides lift up and out so that 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, byfacin
22、g of a bank or embankment with erosion-resistant mate-rial.3.2.11 riprapmaterial 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
23、, or underlying structure. Riprap may be specificallyproduced for the intended 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 in
24、situ or excavated material.4. Significance and Use4.1 Riprap is a commonly 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 s
25、ubgrade settlement. It is often appropriate for use inconjunction with soil 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
26、typically minimized whileproviding the necessary resistance to scour. In this 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 orga
27、nizations, anddesigners and specifiers who are involved in the construction 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
28、specifications are notjustified. If this practice is included by reference 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
29、, thickness,and lateral extent of a riprap revetment. For some smallprojects, 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 justi
30、fied to minimizematerial costs and reduce the chance of failure. The degree 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 inclu
31、des factors which should beconsidered, but are beyond the scope of this guide. 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 1Slop
32、e stability should always be considered. If it is notinvestigated analytically 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 allowa
33、ble slopes (usually in the range of 1.5H:1Vto 3H:1V); however, these must 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.
34、In some cases, a source may be established based onrock classification, geologic 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 fo
35、r rock are dependent on the conditions (such as abrasionand saturation frequency 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 a
36、lsobe screened from a gravel pit operation, processed from rockcollected from 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 environmentalconseque
37、nces and may not be allowed under state and federal permits.6.1.1 Sampling and Testing Rock SourcesPractice D4992provides guidance on sampling a source rock. Acceptance4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.D6825 1412criteria, as outlined in EM
38、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 which the sample was taken, and thestratigraphy for samples obtained at quarries. (See Note 3).NOTE 3Due to the relative cost
39、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 the materialand the Owner later rejects the material at the placement site. Contractspecifications should clearly state wher
40、e the riprap will be sampled fortesting and what constitutes final acceptance 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 aff
41、ecting filtration of thesubgrade, and typical quarry processing capabilities. 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 surf
42、ace to hydraulic flowgenerating greater tractive shear stress, which may lead 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 segregatio
43、n and loss of the small stones.6.2.1 Sampling and Testing Material GradationsThe 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
44、test plots. Bedding andfilter materials should be sampled in accordance with 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
45、relationship. Both parties shouldmake an effort to be present during rock source 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
46、run material must be placed in greater thickness and stonesize than processed 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
47、 of naturalmaterials. The material must be appropriate for the intendeduse. 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 requiremen
48、ts and the aspectratio of individual stones.7. Filter Materials7.1 Purpose 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
49、areselected to provide soil retention and adequate permeability forsubgrade 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 oftough, durable particles, free from thin, flat and elongatedTABLE 1 Predominant Factors for Placement and Maintenance of RiprapFactorSiteConditionDesignControlConstructionControlPostC
