1、Designation: D 7277 08Standard Test Method forPerformance Testing of Articulating Concrete Block (ACB)Revetment Systems for Hydraulic Stability in Open ChannelFlow1This standard is issued under the fixed designation D 7277; the number immediately following the designation indicates the year oforigin
2、al adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 The purpose of this test method is to provide specifica-tions for
3、 the hydraulic testing of full-scale articulating concreteblock (ACB) revetment systems under controlled laboratoryconditions for purposes of identifying stability performance insteep slope, high-velocity flows. The testing protocols, includ-ing system installation, test procedures, measurement tech
4、-niques, analysis techniques, and reporting requirements aredescribed in this test method.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered stan
5、dard.1.2.1 The gravitational system of inch-pound units is usedwhen dealing with inch-pound units. In this system, the pound(lbf) represents a unit of force (weight), while the unit for massis slugs. The rationalized slug unit is not given, unless dynamic(F = ma) calculations are involved.1.3 This s
6、tandard 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.
7、1 ASTM Standards:2D 422 Test Method for Particle-Size Analysis of SoilsD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D 1556 Test Method for Density and Unit Weight
8、 of Soil inPlace by Sand-Cone MethodD 2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD 2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D 4318 Test Methods for Liquid Limit, Plastic Limit, andPl
9、asticity Index of SoilsD 5195 Test Method for Density of Soil and Rock In-Placeat Depths Below the Surface by Nuclear Methods3. Terminology3.1 Definitions: For common definitions of technical termsin this test method, refer to Terminology D 653.3.1.1 articulating concrete block (ACB) revetment syste
10、m,nin erosion control, a matrix of interconnected concreteblock units for erosion protection. Units are typically con-nected by geometric interlock, cables, ropes, geotextile, geo-grids or a combination thereof and typically include a geotex-tile underlayment.3.1.2 depth of flow, yo,(L), nin hydraul
11、ics, the distancefrom the channel thalweg to the water surface, measurednormal to the direction of flow, for a given discharge.3.1.3 design discharge, Qd,(L3T1), nin erosion control,the volumetric quantity of water flow within a channel whichis typically used in determining required channel dimensio
12、nsand suitable lining materials for ensuring adequate channelcapacity and stability.3.1.3.1 DiscussionThe discharge associated with a speci-fied frequency of recurrence, for example, an n-year flood. Then-year flood event has a probability of 1/n of being equaled orexceeded in any given year.3.1.4 d
13、ischarge, Q, (L3T1), nin channel flow, the volumeof water flowing through a cross-section in a unit of time,including sediment or other solids that may be dissolved in ormixed with the water; usually cubic feet per second (ft3/s) orcubic meters per second (m3/s).1This guide is under the jurisdiction
14、 ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.25 on Erosion and SedimentControl Technology.Current edition approved Aug. 1, 2008. Published September 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Servic
15、e 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.3.1.5 hydraulic radius, (L), nin channel flow,
16、 the cross-sectional area of flow divided by the wetted perimeter.3.1.6 local velocity, (L3T1), nin channel flow, the veloc-ity at a specific point in the flow region. May be defined as adirection-dependent quantity with components Vx, Vy,orVz.3.1.7 mean velocity, (LT1), nin hydraulics, the averagev
17、elocity throughout a channel cross section. Defined as thedischarge divided by the cross-sectional area of flow usuallyexpressed in meters per second (m/s) or feet per second (ft/s).3.1.8 subcritical flow, (LT1), nin channel flow, a charac-teristic of flowing water whereby gravitational forces domin
18、ateover inertial forces, quantified by a Froude Number less than 1.3.1.9 supercritical flow, (LT1), nin channel flow, a char-acteristic of flowing water whereby inertial forces dominateover gravitational forces, quantified by a Froude Numbergreater than 1.3.1.10 uniform flow, (LT1), nin hydraulics,
19、the conditionof flow where the rate of energy loss due to frictional and formresistance is equal to the bed slope of the channel.3.1.10.1 DiscussionWhere uniform flow exists, the slopesof the energy grade line, the water surface, and the channel bedare identical. Cross-sectional area and velocity of
20、 flow do notchange from cross section to cross section in uniform flow.3.1.11 velocity, V, (LT1), nin channel flow, time rate oflinear motion in a given direction.4. Summary of Test Method4.1 The test method is designed to determine the stabilitythreshold values of shear stress and velocity of artic
21、ulatingconcrete block (ACB) revetment systems under controlledlaboratory conditions of steep-slope, high-velocity flow (flumetest). Systems are tested as full-scale production units.4.2 The procedures associated with test set-up, testing, datacollection, and reporting are provided in this test metho
22、d.5. Significance and Use5.1 An articulating concrete block revetment system iscomprised of a matrix of individual concrete blocks placedtogether to form an erosion-resistant revetment with specifichydraulic performance characteristics. The system includes afilter layer compatible with the subsoil w
23、hich allows infiltrationand exfiltration to occur while providing particle retention. Thefilter layer may be comprised of a geotextile, properly gradedgranular media, or both. The concrete blocks within the matrixshall be dense and durable, and the matrix shall be flexible andporous.5.2 ACB revetmen
24、t system are used to provide erosionprotection to underlying soil materials from the forces offlowing water. The term “articulating,” as used in this standard,implies the ability of individual concrete blocks of the systemto conform to changes in subgrade while remaining intercon-nected by virtue of
25、 geometric interlock, cables, ropes, geotex-tiles, geogrids, or combination thereof.5.3 The definition of ACB revetment system does notdistinguish between interlocking and non-interlocking blockgeometries, between cable-tied and non-cable-tied systems,between vegetated and non-vegetated systems or b
26、etweenmethods of manufacturing or placement. Furthermore, thedefinition does not restrict or limit the block size, shape,strength, or longevity; however, guidelines and recommenda-tions regarding these factors are incorporated into this stan-dard. Blocks are available in either open-cell or closed-c
27、ellconfigurations.6. Preparation of Test Section6.1 Soil Subgrade Construction:6.1.1 The testing program includes the construction of anearthen test subgrade compacted between vertical walls of thetesting flume (Fig. 1). The soil subgrade shall be placed andcompacted in horizontal lifts of 4 to 6 in
28、. (100 to 150 mm) inthickness to a minimum subgrade thickness of 12 in. (300 mm).The distance between the walls shall be a minimum of 4.0 ft(1.2 m); installation shall be reflective of standard field usageand shall accommodate full-scale block units such that at leastone block is not adjacent to a s
29、idewall, at least every other rowof the revetment matrix.6.1.2 The soil subgrade shall consist of a silty sand with aplasticity index (PI) in the range of 2 to 6 %, and will becompacted at optimum water content to between 90 and 95 %of Standard Effort density (Test Methods D 698). The embank-ment sh
30、all be constructed to a height such that the finishedsurface of the revetment consists of a horizontal crest section atleast 6 ft (1.8 m) in length followed by a downstream slopeangle typically set at 2H:1V.NOTE 1Test conditions may incorporate slopes other that the 2H:1Videntified as the benchmark.
31、 Variations from the procedures identifiedmust be included in the report. Additionally, engineering judgment mustaccompany utilizing and interpreting the results from tests varying fromthe proposed test method.6.1.3 Soil information to be determined and documentedprior to and during test embankment
32、construction includes, asapplicable:6.1.3.1 Standard Effort moisture-density curve, Test Meth-ods D 698.6.1.3.2 Soil textural classification, Practice D 2487.6.1.3.3 Particle size distribution curve (including hydrom-eter fraction), Test Method D 422, and6.1.3.4 Atterberg Limits (liquid limit, plast
33、ic limit), TestMethods D 4318.6.1.4 Following the preparation of the soil subgrade, thefollowing information is determined within 24 h prior toinstallation of the revetment system. This information shallinclude as a minimum the soil water (moisture) content (TestMethods D 2216) and density/unit weig
34、ht determined by sandcone (Test Method D 1556) or nuclear gauge (Test MethodD 5195) at a minimum of two locations along the centerline ofthe test embankment.6.2 Installation of ACB Revetment System:6.2.1 A properly designed filter (geotextile, granular filter,or both), properly engineered or selecte
35、d for the soil subgradeutilized for testing, and the ACBs shall be placed on the crestand downstream slope in accordance with the manufacturersrecommendations. Potential artificially induced scour along thesidewalls will be prevented by placing geotextile wadding,protective flashing, loose grout or
36、a combination, along theedge of the ACB revetment system (Fig. 2). The chosen sideprotection shall allow nominal block movement and not pressD7277082NOTE 1Drawing not to scale, and slope, as shown, is not 2H:1V.NOTE 21 ft = 0.305 m.FIG. 1 Schematic Profile of Typical Testing FlumeD7277083the block o
37、nto the subgrade. Side protection shall permit a gapa above the blocks a minimum of 0.25 in. (6.4 mm) and amaximum of 0.75 in. (19 mm) in the vertical direction.Horizontal projection of the side protection shall extend aminimum of 0.5 in. (13 mm) and a maximum of 2.5 in. (64mm) into the flume. The A
38、CB revetment system will besecured at the embankment toe by means of a bolted or weldedtoe retention system designed for the specific system to betested (Fig. 3). Depending on the geometry of the system beingtested, void spaces next to the sidewalls greater than 3 in. (75mm) should be filled with pa
39、rtial blocks specially cut with amasonry saw to fill the void, while maintaining the propergeometric relationship of the matrix. Under no circumstancesshould the void spaces against the sidewall be filled anycompound that bonds the block to the sidewall or prevents thesystem from its inherent abilit
40、y to articulate. As shown in Fig.1, a joint between the ACBs shall occur at the crest (top) of theslope.7. Procedure7.1 Definition of TestA test consists of a continuousfour-hour flow over the ACB revetment system at a uniformdischarge. Providing that the ACB revetment system success-fully survives
41、the four-hour flow without deformation, soilloss, or loss of solid contact with the soil subgrade, theprocedure is repeated at the next higher target discharge oruntil the flow capacity of the testing facility is reached.Typically, target discharges correspond to predetermined over-topping depths ab
42、ove the revetment systems crest elevation(for example, 1 ft (0.3 m), 2 ft (0.6 m), etc.), although anydischarge may be utilized provided proper measurement andreporting procedures are followed as described in this docu-ment. Even if minor system deformation occurs during the test,hourly data collect
43、ion shall be maintained for the entirefour-hour test duration, unless catastrophic ACB revetmentsystem failure occurs.7.2 Water Surface and Bed Elevation ProfilesHourlymeasurements of water surface elevation will be made at 2-ft(0.6-m) intervals (stations) along the centerline of the embank-ment dur
44、ing each test. Bed elevations (top of ACB revetmentsurface) shall be established prior to each test and again afterthe cessation of each test, at the same measurement stations asthe water surface readings. When testing ACBs that exhibit astaggered layout pattern such that there may not be a block at
45、the centerline location at every measurement station, an adja-cent block to the left or right of the centerline may be selectedas the measurement point. Those ACBs should be identifiedwith a paint mark to ensure consistency in measurement.Measurements should be made to the nearest 0.01 ft (0.003 m)u
46、sing point gauge, survey level, or other suitable elevation-measuring device. Suitable stationing positions should beestablished so that the horizontal location of each measurementstation does not vary between subsequent measurements.7.3 Water Velocity MeasurementsHourly measurementsof point velocit
47、y shall be made at two-tenths, six-tenths, andeight-tenths depth of flow, measured from the water surfacedown, at 4-ft (1.2-m) intervals along the centerline stationing,and shall correspond to every other water surface measurementstation. In areas where depth is insufficient to provide velocitymeasu
48、rements at these three depths, one measurement atsix-tenths depth shall be made. The velocity measurementsshall be made with an electromagnetic current meter, Price-type pygmy (mini) current meter (“spinning cup”), or pitot tubeflow meter. The axis of the device shall be maintained at anangle normal
49、 to the plane of the embankment while themeasurement is made.7.4 Total Discharge DeterminationThe total discharge,Qt, shall be determined independently of the measurementsbeing made in the test section. Suitable determinations can bemade by using primary flow meter, in-line flow meters (ultra-sonic, propeller, orifice plate, etc.) placed in the supply pipe, orby funneling the flow through an open-channel primary flowmeter, such as a Parshall or cutthroat flume, sharp-crested orvolumetric tank, after the water exits the test section.FIG. 2 Recommended Sid
