ASTM_D_6939_-_03.pdf

Designation:D 6939 03Standard Practice forBrushmattressing1This standard is issued under the fixed designation D 6939;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the material,preparation and instal-lation work required for brush-mattress construction used insoil bioengineering.1.2 The values in this standard are in SI units and are to beregarded as the standard.The inch-pound units given inparentheses are for information only.1.3 This practice offers a set of instructions for performingone or more specific operations.This document cannot replaceeducation or experience and should be used in conjunction withprofessional judgment.Not all aspects of this practice may beapplicable in all circumstances.This ASTM standard is notintended to represent or replace standard of care by whichadequacy of a given professional service must be judged,norshould this document be applied without considerations of aprojects many unique aspects.The word“standard”in the titleof this document means only that the document has beenapproved through the ASTM consensus process.1.4 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.2.Referenced Documents2.1 ASTM Standards:2D6765 Practice for Live Staking3.Terminology3.1 Definitions:3.1.1 brushmattress,na layer of live woody materialanchored with stakes and ties installed to cover and stabilizestream banks and shorelines.4.Summary of Practice4.1 A brushmattress is a layer of live woody plant materialinstalled to cover and stabilize stream banks.Dead StoutStakes(and/or Live Stakes)and ties(wire,string,rope,bailingtwine)are used to anchor the material.Brushmattressing iscommonly used on stream banks,shorelines and other moistenvironments.Often,a live fascine and/or rock toe is used atthe base.The branches collect sediment as well as provideimmediate protection against surface erosion.The live cuttingseventually root and provide permanent reinforcement.5.Significance and Use5.1 Abrushmattress is used to provide erosion and sedimen-tation control primarily by armoring the bank.In addition toshielding the surface,a brushmattress can increase infiltration,slow runoff,and trap seed and sediments.This method pro-vides surface slope stabilization through vegetative growth andshallow soil reinforcement through root development.Theability of a brushmattress to function properly depends on thequality and choice of the materials used to construct thebrushmattress,the means and methods of fabrication andinstallation,and proper consideration of site characteristics andtime of year.For the brushmattress to function completely,it isimportant that the live material develops suitable growth.Thebrushmattress helps to control soil erosion while serving ashabitat for birds,small mammals,invertebrates and otherorganisms that in turn,are fed upon by fish and other higherorganisms.Once the vegetation matures,it can provide shadeto the streamlowering water temperatures,offering protec-tion from predators,and generally improving fish habitat.Figs.1-3 show a brushmattress immediately after construction,inthe first growing season,and in the 2nd season.6.Materials6.1 Live Woody Plant MaterialStem and branch cuttingsof vegetativly self-propagating woody plant species.Typically,branches are harvested near the project site within the sameclimatic zone.The greatest success results from cutting andinstalling vegetation during the dormant season.Leave sidebranches intact and use only fresh or well-preserved viablecuttings.All material should be free of splits,rot,disease,andinsect infestation.The stems or branches should be long1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.25 on Erosion andSediment Control Technology.Current edition approved August 10,2003.Published December 2003.2For referenced ASTM standards,visit the ASTM website,www.astm.org orcontact ASTM Customer Service at service astm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.enough to allow the placement of the basal ends below thelowest water level that occurs during the growing season andfor the growing tips overlap the top of the slope.This istypically at least 0.6 m(2 ft)longer than the length of slope.The caliper(diameter)of cuttings generally range from 12 to25 mm(0.5 to 1 in.).6.2 Brush Cutt