1、Designation: D 6825 02 (Reapproved 2008)e1Standard Guide forPlacement of Riprap Revetments1This standard is issued under the fixed designation D 6825; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTESections X1.1-X1.3 were corrected editorially in February 2008.1. Scope1.1 This guide covers methods to place riprap with associ-ated filters f
3、or erosion control purposes. 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 p
4、roduction of rock, use of recycled materials,rock with cut dimensions, and engineering and design isbeyond the scope of this guide. Special forms of riprap,including hand placed riprap, grouted riprap, or keyed (plated)riprap that is tamped into place to smooth the surface, are alsobeyond the scope
5、of this guide.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
6、applicable 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
7、title of thisdocument means only that the document has been developedand approved through the ASTM consensus process1.3 This standard may involve hazardous operations andequipment. This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsi
8、bility 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.2. Referenced Documents2.1 ASTM Standards:2C33 Specification for Concrete AggregatesC 136 Test Method for Sieve Analysis of Fine and Coar
9、seAggregatesD75 Practice for Sampling AggregatesD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 4992 Practice for Evaluation of Rock to be Used forErosion ControlD 5519 Test Methods for Particle Size Analysis of Naturaland Man-Made Riprap MaterialsD 6092 Practice for Specifying Standa
10、rd Sizes of Stone forErosion Control2.2 AASHTO Standard:3M 2882000 Geotextile Specification for HighwayApplica-tions3. Terminology3.1 Terminology used in this guide, which is not included ornot completely defined in Terminology D 653, is definedbelow.3.2 Definitions of Terms Specific to This Standar
11、d:3.2.1 beddingan aggregate mixture placed below theriprap. Bedding material is usually sand and gravel sized, butmay include cobble sized material. If placed without a geotex-tile, the bedding material may be used as a filter. If placed inconjunction with a geotextile, the bedding may provide acush
12、ion 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 rock or aggregate.1This guide is under the jurisdiction ofASTM Committ
13、ee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.17 on Rock for ErosionControl.Current edition approved Jan. 1, 2008. Published February 2008. Originallyapproved in 2002. Last previous edition approved in 2002 as D 6825 02e2.2For referenced ASTM standards, visit the ASTM w
14、ebsite, 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 Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St
15、., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.3 clam shella bucket tool that is operated from adragline or crane. The bucket is hinged at the top and openslike
16、 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.3.2.5 filterany substance, as geotextile or layer of sand/aggregate, placed to provide separation and retention of mate-rials, while allo
17、wing water to pass.3.2.6 floatera individual rock within the 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 p
18、eela bucket tool that is operated from adragline or crane and 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
19、.3.2.10 revetmentbank protection by armor, that is, byfacing 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
20、currents and thereby preserves the shape of a surface,slope, 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 o
21、ccurring in large masses or fragments. Rock may beeither insitu 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 s
22、o it will conform to irregular surfaces and adapt tominor subgrade 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 faci
23、ng or lining to armor asurface; and the layer thickness is 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, in
24、stallation contrac-tors, regulatory agencies, inspection organizations, and design-ers and specifiers who are involved in the construction of ripraprevetments. Modifications may be required for specific jobconditions.This guide is not intentded for construction speci-fications on large projects, but
25、 may be referenced wherepreparation of job specific construction 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 req
26、uired, construc-tion methods, and equipment may affect the sizing, 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
27、, careful placement,and quality control become increasingly justified 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 investi
28、gation and other considerationsincluded in Table 1. Table 1 includes factors which should beconsidered, but are beyond the scope of this guide. Somerecommended publications for further information on thesefactors and engineering criteria are given in the Referencessection. Designing the revetment is
29、 beyond the scope of thisguide.NOTE 1Slope 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). Man
30、y agencies havegeneralized maximum allowable 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
31、 EvaluationRock must be durablematerial. 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 req
32、uired. Acceptable material proper-ties for rock is 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 com
33、monly produced at a quarry, but it may alsobe 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
34、disturbed may have environmentalconsequences and may not be allowed under state and federal permits.6.1.1 Sampling and Testing Rock SourcesPractice D 4992provides guidance on sampling a source rock. Criteria foracceptance should consider criteria in EM 1110-2-2302, butmay also consider characteristi
35、cs 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 of producing and transporting riprapin relation to placing it at th
36、e 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 where the riprap will be sampled fortesting and what constitutes final
37、acceptance of the material.D 6825 02 (2008)e126.2 Riprap GradingRecommended gradation require-ments for processed riprap are given in Practice D 6092. Thegradations are considered to be optimum size variationsconsidering rock stability, riprap voids affecting filtration of thesubgrade, and typical q
38、uarry 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 with uniform sizedrocks have a rough surface which maximizes the tractive shearstress on the rocks,
39、 which detracts from the stability. Materialthat is too broad in grading is susceptible to segregation andloss of the small stones.6.2.1 Sampling and Testing Material GradationsTheriprap grading should be verified. When gradation tolerancesare critical, the grading should be determined in accordance
40、with Practice D 5519. Riprap samples should be taken fromstockpiles, loaded trucks or in place test plots. Bedding andfilter materials should be sampled in accordance with PracticeD75and tested in accordance with Test Method C 136.NOTE 4Due to the economical limitations of obtaining the numberand si
41、ze of samples to be statistically meaningful, the Owner andContractor should have a partnering 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 a
42、vailability, and broadergrading. For similar rock stability and filtration characteristics,pit 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
43、 recycled material is generally more difficult andthe material must be appropriate for the intended use. Crushedhydraulic-cement concrete may be obtained from varioussources with inconsistent strength and durability. Slabs in thesource material and the amount of reinforcing steel cancomplicate contr
44、ol of the grading requirements and the aspectratio of individual stones.7. Filter Materials7.1 Purpose of FiltersFor revetments placed as thinfacings 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 beddin
45、g or geotextiles. Filters 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 pass
46、age. In some cases,multiple layers may be required.7.2 BeddingBedding material should be composed oftough, durable particles, free from thin, flat and elongatedpieces, and should contain minimal quantities of organic matterand soft friable particles.Aggregates should generally meet thequality requir
47、ements of Specification C33. Some typicalgradation requirements for bedding materials are given inPractice D 6092. It is sometimes more economical to specify acommonly produced gradation, such as a state transportationdepartment gradation for concrete or bituminous aggregate. Itmay be necessary to a
48、djust the gradation requirements to meetfilter requirements for protection of the subgrade soils.7.3 GeotextilesThe geotextiles must have adequatestrength to withstand installation stresses during placement.AASHTO M 28800 provides recommended geotextile prop-erties for survival during construction.
49、The geotextile proper-ties listed in AASHTO M 28800 are related to specificplacement conditions and equipment operation.TABLE 1 Predominant Factors for Placement and Maintenance of RiprapNo. FactorSiteConditionDesignControlConstructionControlPostConstructionControl1 Hydraulic bed shear stressflow velocity or wave amplitudeflow turbulenceflow depth or wave run-upwater density (salinity)X2 Debris impact and ice action X X3 Bed slope, side slopes (hydraulic stability) X X4 Slope Stability (see Note 1)X5 Site Conditions (under water placement, temporary acc
