1、Designation: D 5852 00 (Reapproved 2007)Standard Test Method forErodibility Determination of Soil in the Field or in theLaboratory by the Jet Index Method1This standard is issued under the fixed designation D 5852; the number immediately following the designation indicates the year oforiginal adopti
2、on 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 test method covers the estimation of erodibility ofa soil by a jet i
3、ndex method. This test method involves eitherpreparing a field site or obtaining a relatively undisturbed soilsample and the subsequent activities for the determination ofthe erodibility of soil. This test method also may be run oncompacted samples in the laboratory.1.2 The values stated in SI units
4、 are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 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 pract
5、ices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 420 Guide to Site Characterization for Engineering De-sign and Construction PurposesD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 2216 Test Methods for Laborator
6、y Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD 2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)D 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and Con
7、structionD 4220 Practices for Preserving and Transporting SoilSamplesD 4753 Guide for Evaluating, Selecting, and SpecifyingBalances and Standard Masses for Use in Soil, Rock, andConstruction Materials Testing3. Terminology3.1 Definitions:3.1.1 For common definitions of terms in this standard, refert
8、o Terminology D 653.4. Significance and Use4.1 Water flow in nature exerts a force on soils that resultsin erosion. Erosion potential of a soil is of concern in vegetatedchannels, road embankments, dams, levees, spillways, con-struction sites, etc. The jet index method is intended to providea standa
9、rd method of expressing erosion resistance; to assistthose who work with different soils and soil conditions tomeasure erosion resistance for design purposes; and to providea common system of characterizing soil properties to developperformance and prediction relationships.4.2 The jet index test is
10、not suited for determining erodibil-ity of soils that have structure characteristics larger than thescale of the jet testing device. For example, the erodibility ofsoil that has a dominant soil structure of 7 to 8 cm or larger(that is, aggregate, clod, or particle size), that might play a keyrole in
11、 the detachment process, should not be estimated withthe jet index test. Care should be taken that the test sample andtest are representative of expected conditions at the site underinvestigation. If it is known in advance that the soil will besaturated prior to an erosion event, then the soil shoul
12、d betested in that condition. At present, the effects of waterchemistry on detachment rate are unknown. Therefore, waterquality during testing should be simulated as close as possibleto the water quality anticipated during actual erosion.NOTE 1The quality of the result produced by this standard is d
13、ependupon the competence of the personnel performing it, and the suitability ofthe equipment and facilities used. Agencies that meet the criteria ofPractice D 3740 are generally considered capable of competent andobjective testing and sampling. Users of this standard are cautioned thatcompliance wit
14、h Practice D 3740 does not in itself assure reliable results.Reliable results depend on many factors; Practice D 3740 provides ameans of evaluating some of those factors.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee
15、D18.02 on Sampling andRelated Field Testing for Soil Evaluations.Current edition approved July 1, 2007. Published August 2007. Originallyapproved in 1995. Last previous edition approved in 2000 as D 5852 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
16、 Service at serviceastm.org. For Annual Book of ASTMStandards volume 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.5. Apparatus5.1 Field Testing:5.1.1 Ver
17、tical Submerged Jet DeviceAn apparatus thatcan be taken to the field to index soil erodibility (see Fig. 1).The device is mounted on a base ring with a sealing ring toprevent leakage and piping.Acylindrical tank is attached to thebase ring to act as a weir while maintaining the water levelrequired t
18、o submerge the jet. The soil surface inside the deviceis 0.44 m in diameter. Attached to the tank is an innercylindrical liner that acts as a baffle to minimize returnturbulence to the jet. The jet and pin profiler (see Fig. 2 andFig. 3) are interchangeable and are mounted to the uppersurface of thi
19、s liner. A 51-mm diameter clear acrylic tube, thelower end of which is fitted with a 13-mm diameter nozzle, ismounted in a hanger that can be set on the inner cylindricalliner.NOTE 2Detailed drawings of the apparatus and supporting equipmentare available from ASTM Headquarters.5.1.2 Pin Profiler, us
20、ed to determine the maximum depth ofmaterial removed during testing.5.1.3 Water Delivery System, required to run the jet test.Water delivery may be accomplished by pumping directly froma body of water at the site, from a storage tank delivered to thesite, or from a city water supply system if availa
21、ble.5.1.4 Differential Pressure Device, necessary in order todetermine the mean velocity at the jet nozzle. This may beaccomplished by manometers, differential pressure gage, orpressure transducer.5.1.5 Pressure Control, necessary to maintain a constantvelocity at the jet nozzle. This may be accompl
22、ished by aconstant head tank or a valve.5.1.6 LevelA carpenters level is necessary to level thefoundation ring and inner liner of the tank.5.1.7 ShovelA flat-nosed shovel is useful in preparing thesite for testing.5.1.8 RulerA ruler is required to set the jet nozzle at aheight of 0.22 m above the un
23、scoured soil surface.5.1.9 Miscellaneous EquipmentA 10 to 13 cm diameterflat disk, sledgehammer, wrenches, plastic bags and other soilsampling equipment for other soil tests of interest.5.2 Laboratory Testing:5.2.1 Vertical Submerged Jet DeviceAn apparatus that isused in the laboratory to determine
24、soil erodibility (see Fig. 4).The device consists of a lower cylindrical tank that slides undera fixed upper cylindrical tank. The upper and lower cylindricaltanks are sealed together with an inflated tube to preventleakage during testing. The sample is loaded into the lowertank and slid under the u
25、pper tank. The upper tank acts as aweir while maintaining the water level required to submergethe jet. The soil samples are contained in pvc molds with aninner diameter of 0.44 m and a height of 0.18 m. Attached tothe tank is an inner cylindrical liner that acts as a baffle toFIG. 1 Submerged Jet Ap
26、paratus for Field TestingFIG. 2 Jet Apparatus in OperationD 5852 00 (2007)2minimize return turbulence to the jet. The jet and pin profilerare interchangeable, mounted to the upper surface of this liner.A 51-mm diameter clear acrylic tube, the lower end of whichis fitted with a 13-mm diameter nozzle,
27、 is mounted in a hangerthat can be set on the inner cylindrical liner.5.2.2 MoldA large mold is required for obtaining rela-tively undisturbed samples from the field. Due to the size of thesamples required, pvc molds are recommended to minimize themass of the sample. The mold size recommended consis
28、ts of0.44 m inner diameter and 0.18 m height. Once a mold sampleis obtained in the field, it should be immediately covered atboth ends with stiff plastic disks held firmly with a framingsystem. Sampling and preserving/transporting soils samplesare done in accordance with Guide D 420 and Practice 422
29、0respectively.5.2.3 Cutting HeadA cutting head is essential for takingsamples this size in the field. The cutting head is mounted tothe front end of the mold and driven in or pushed in advanceof the mold. The procedure for obtaining a sample is toadvance the mold and cutting head 5 to 8 cm at a time
30、, removethe material around the outside of the mold and repeat theprocess until the mold is to the desired depth.5.2.4 Straight EdgeA straight edge is necessary to trimboth ends of the sample flush with the mold.5.2.5 ShovelAny one of several types of shovels or spadesis satisfactory for shallow sam
31、pling when digging around themold.5.2.6 BalancesAll balances shall meet the requirementsof Specification D 4753 and this section. A balance or scale ofat least 100 kg capacity is required for determining the mass ofthe mold and sample. A balance or scale of 500 g capacity isrequired to determine fie
32、ld water content of disturbed samples.5.2.7 Drying EquipmentEquipment and oven are requiredto determine water content. Water contents shall be determinedin accordance with Test Method D 2216.5.2.8 Water Delivery System, Differential Pressure Device,and Pressure ControlEquipment necessary for water d
33、eliv-ery, differential pressure control and measurement are neces-sary for both the laboratory device and for the field testingdevice.5.2.9 Miscellaneous EquipmentA 10 to 13 cm diameterflat disk, sledgehammer, plastic bags, cans, gloves, wrenchesand ruler.6. Procedure6.1 Field Testing:6.1.1 Prepare
34、the surface at the test location so that it isreasonably level and void of vegetation. When the site is readyfor testing, push the base ring into the soil. This may requirethe use of a sledgehammer, impacting on a wood cushion (suchas a two by four) to protect the base ring from damage. Thebase ring
35、 should then be checked to make sure it is relativelylevel.6.1.2 Set the backwater tank in place over the base ring andlatch down. Place the cylindrical liner on the leveling bolts ofthe backwater tank and level. Use the pin profiler to determinethe pre-testing soil elevation. Pre-set the head on th
36、e jet deviceso that only minor nozzle adjustments are necessary at thebeginning of the test. Do this by placing it in a 5 gal (about 19L) bucket near the same elevation as the backwater tank andmake necessary adjustments to the head differential on thenozzle. Although other head settings may be used
37、, the recom-mended head setting on the jet is 0.91 m (36 in.). Remove thepin profiler and backfill the tank with water. Place the jetapparatus on the backwater tank cylindrical liner. Hold a flat 10to 13 cm diameter disk approximately 3 cm from the nozzleoutlet and make final adjustments to the head
38、. The flat diskprevents discharge from the nozzle from impinging directly onthe sample prior to testing. Remove the disk from the discharg-ing jet to initiate testing.Atiming sequence of 600, 1200, 1800,and 3600 s intervals is recommended for a total testing time of7200 s. Other timing sequences are
39、 at the discretion of the user.A pin profile of the surface of the tested soil sample shall betaken after each time sequence (see Fig. 3). Following testing,equipment clean up is essential.6.1.3 Before testing, the inner cylinder should be made leveland the nozzle jet height should be set at 0.22 m
40、above thesurface of the soil sample. Before testing begins, the fluid headon the jet should be set close to 0.91 m so that only minoradjustments are necessary at start up of testing.6.2 Laboratory Testing:6.2.1 Pre-set the head on the jet device. Load the sampleinto the lower tank and slide the samp
41、le under the upper tank.Pressurize the sealing tube between the upper and lowercylinders of the testing apparatus.6.2.2 Use the pin profiler to determine the pretesting soilelevation. Remove the pin profiler and backfill the tank withwater. Place the jet apparatus on the backwater tank cylindricalli
42、ner. Hold a flat 10 to 13 cm diameter disk approximately 3 cmfrom the nozzle outlet and make final adjustments to the head.The flat disk prevents discharge from the nozzle from imping-ing directly on the sample prior to testing. Remove the diskfrom the discharging jet to initiate testing. A test tim
43、ingsequence of 600, 1200, 1800, and 3600 s intervals is recom-mended for a total testing time of 7200 s. Other timingsequences are at the discretion of the user. A pin profile of thesurface of the tested soil sample shall be taken after each timesequence. Following testing, equipment clean up is ess
44、ential.FIG. 3 Pin Profile Following a Time SequenceD 5852 00 (2007)36.2.3 Before testing, the inner cylinder should be made leveland the nozzle jet height should be set at 0.22 m above thesurface of the soil sample. Before testing begins, the fluid headon the jet should be set close to 0.91 m so tha
45、t only minoradjustments are necessary at start up of testing.7. Calculation7.1 Calculate the velocity of the jet at the nozzle:Uo5 C=2gh (1)where:Uo= velocity of the jet at the nozzle (cm/s),g = acceleration due to gravity (981 cm/s2),h = head on the jet (cm), andC = nozzle coefficient.A rounded noz
46、zle is used in this apparatus (see the detailedplans). Therefore, a nozzle coefficient of one may be assumed.7.2 Determine the maximum depth of scour for each timeinterval (see Fig. 3):D 5(li(p 5 1517Rpt2 Rp0!n(2)where:Ds= average maximum depth of scour determined fromprofile pins 15, 16, and 17 for
47、 each profile readingtaken for each time sequence (cm),i = number of profiles read (cm),p = pin numbers of interest,Rp0= pin reading at time 0 (cm),Rpt= pin reading for the time sequence of interest (cm),andn = total number of pin readings (i 3 3).FIG. 4 Submerged Jet Apparatus for Laboratory Testin
48、gD 5852 00 (2007)47.3 Determine the jet index by plotting Ds/t versusUo(t)0.931with t in seconds.3Dsshould be measured to thenearest 1 mm, 3 to 1s, and Uoto 1 cm/sec. The slope of theline, passing through zero, created by a least squares fit of thedata is the jet index (see Fig. 5). If the sample sc
49、ours to thedepth of the sample in the first time sequence of testing (600 s),the slope of the line through zero and the single resulting pointresults in an estimate of the jet index. Based on experience,typical values of the jet index range from 0 to 0.03 with a valueof 0.001, 0.01, and 0.02 indicating high resistance, moderateresistance, and low resistance to erosion, respectively.37.4 The jet index is an erosion performance index. If anestimate of the erodibility is desired, further calculations arerequired. Typically, erosion in an open channel is expressed a
