1、Designation: B788/B788M 09Standard Practice forInstalling Factory-Made Corrugated Aluminum Culverts andStorm Sewer Pipe1This standard is issued under the fixed designation B788/B788M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This practice describes
3、 procedures, soils, and soil place-ment for the proper installation of corrugated aluminumculverts and storm sewers in either trench or projectioninstallations. A typical trench installation is shown in Fig. 1,and a typical embankment (projection) installation is shown inFig. 2. The pipes described
4、in this practice are manufactured ina factory and furnished to the job in lengths ordinarily from 10to 30 ft 3 to 9 m, with 20 ft 6 m being common, for fieldjoining. This practice applies to structures designed in accor-dance with Practice B790/B790M.1.2 The values stated in either SI units or inch-
5、pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.2.1 SI UnitsSI units are shown in
6、the text in brackets,and they are the applicable values for metric installation.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 practices and det
7、ermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B745/B745M Specification for Corrugated Aluminum Pipefor Sewers and DrainsB790/B790M Practice for Structural Design of CorrugatedAluminum Pipe, Pipe-Arches, and Arches for Culverts,Storm Sewer
8、s, and Other Buried ConduitsD698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D1556 Test Method for Density and Unit Weight of Soil inPlace by Sand-Cone MethodD2167 Test Method for Density and Unit Weight of Soil inPlace by the R
9、ubber Balloon MethodD2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D2937 Test Method for Density of Soil in Place by theDrive-Cylinder Method1This practice is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the dir
10、ect responsibility of Subcommittee B07.08 onAluminum Culvert.Current edition approved Nov. 1, 2009. Published December 2009. Originallyapproved in 1988. Last previous edition approved in 2004 as B788/B788M 04.DOI: 10.1520/B0788_B0788M-09.2For referenced ASTM standards, visit the ASTM website, www.as
11、tm.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.FIG. 1 Typical Trench InstallationFIG. 2 Typical Embankment (Projection) Installation1*A Summary of Changes section appears
12、 at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D6938 Test Method for In-Place Density and Water Contentof Soil and Soil-Aggregate by Nuclear Methods (ShallowDepth)3. Terminology3.1 Definitions of Terms Sp
13、ecific to This Standard:3.1.1 bedding, nthe earth or other material on which apipe is supported.3.1.2 haunch, nthe portion of the pipe cross sectionbetween the maximum horizontal dimension and the top of thebedding.3.1.3 invert, nthe lowest point on the pipe cross section;also, the bottom portion of
14、 a pipe.3.1.4 pipe, na conduit having full circular shape; also, ina general context, all structure shapes covered by this practice.3.1.5 pipearch, na pipe with an approximate semicircu-lar crown, small-radius corners, and large-radius invert.4. Significance and Use4.1 Corrugated aluminum pipe funct
15、ions structurally as aflexible ring which is supported by and interacts with thecompacted surrounding soil. The soil constructed around thepipe is thus an integral part of the structural system. It istherefore important to ensure that the soil structure or backfillis made up of acceptable material a
16、nd is well-constructed.Field verification of soil structure acceptability using TestMethods D1556, D2167, D2937,orD6938 as applicable, andcomparing the results with Test Method D698 in accordancewith the specifications for each project, is the most reliablebasis for installation of an acceptable str
17、ucture. The requireddensity and method of measurement are not specified by thispractice, but they must be established in the specifications foreach project.5. Trench Excavation5.1 To obtain anticipated structural performance of corru-gated aluminum pipe it is not necessary to control trench widthbey
18、ond the minimum required for proper installation of pipeand backfill. However, the soil on each side beyond theexcavated trench must be able to support anticipated loads.When a construction situation calls for a relatively wide trench,it shall be made as wide as required, for its full depth if sodes
19、ired. However, trench excavation must be in compliancewith any local, state, and federal codes and safety regulations.6. Foundation6.1 The supporting soil beneath the pipe must provide areasonably uniform resistance to the imposed load, bothlongitudinally and laterally. Sharp variations in the found
20、ationmust be avoided. When rock is encountered, it must beexcavated and replaced with soil. If the pipe runs along acontinuous rock foundation, it is necessary to provide asuitable soil bedding under the pipe. See Fig. 3.6.2 Lateral changes in foundation should never be such thatthe pipe is firmly s
21、upported while the backfill alongside is not.When soft material is encountered during construction andmust be removed in order to provide an adequate foundation,remove the soft material for a distance of three pipe widths,unless the engineer has set another limit. See Fig. 4.6.3 Performance of burie
22、d pipe is enhanced by allowing thepipe to settle slightly under load compared to the columns ofsoil alongside. Thus, for larger pipes it can be beneficial topurposely create a foundation under the pipe itself which willyield under load more than will the foundation under thecolumns of soil to each s
23、ide. It can usually be obtained byplacing a layer of compressible soil of a suitable thickness, lessdensely compacted than the soil alongside, beneath the struc-ture. This creates favorable relative movement between pipeand the soil on each side. It is of particular importance onpipe-arches.6.4 Pipe
24、-ArchesAll pipe-arch structures must have excel-lent soil support at their corners by both the in-situ foundationand the structural backfill. See Fig. 4 and Fig. 5. They do notrequire the same degree of support under their large-radiusinverts.d =12 in./ft 40 mm/m of fill over pipe, with a 24-in. 600
25、-mm maximum.NOTE 1Section B-B is applicable to all continuous rock foundations.FIG. 3 Foundation Transition Zones and Rock FoundationsFIG. 4 Soft Foundation TreatmentB788/B788M 0926.5 The engineer is encouraged to develop details specific tothe site based on the general principles for foundation con
26、di-tions given in 6.1 through 6.4.7. Bedding7.1 Material used for bedding beneath the pipe shall meetthe requirements of this section. Material in contact with thepipe shall not contain rock retained on a 3-in. 75-mm ring,frozen lumps, chunks of highly plastic clay, organic matter,corrosive material
27、, or other deleterious material. It is notrequired to shape the bedding to the pipe geometry. However,for pipe-arches, it is recommended to either shape the beddingto the relatively flat bottom arc or fine-grade the foundation toa slight v-shape. This avoids the problem of trying to backfillthe diff
28、icult area beneath the invert of pipe-arches. See Fig. 5.8. Pipe Installation8.1 All pipe shall be unloaded and handled with reasonablecare. Pipe shall not be rolled or dragged over gravel or rock andshall be prevented from striking rock or other hard objectsduring placement on bedding. Pipe with pr
29、otective coatingsshall be handled with special care to avoid damage. Pavedinverts shall be placed and centered in the invert.8.2 Joining Systems:8.2.1 Purpose of Joining systemsJoining systems forcorrugated aluminum pipe serve several purposes: (1) tomaintain pipe alignment during installation; (2)
30、to join the endsof pipe sections that will subsequently be buried; (3) to createa continuous flow line; and (4) to limit the amount ofinfiltration of backfill material into the pipe and to limitexfiltration of the flow through the pipe.8.2.2 Joint System ComponentsThe joining system shallbe specifie
31、d by the project engineer. The components shallconform to the requirements of Specification B745/B745M.The pipe fabricator shall provide the components specified forthe project or as designated by the fabricator in accordancewith Specification B745/B745M, Ordering Information. Con-formance of the jo
32、ining system components with the projectrequirements shall be verified upon delivery to the project site.8.2.3 Joining System InstallationThe performance of thepipe line and the joining system will be achieved only when allcomponents of the pipe system are properly installed. As anintegral portion o
33、f the pipe system, the joining system must beassembled in accordance with the details in the project draw-ings or the recommendations provided by the pipe fabricator.8.2.3.1 GasketsIf gaskets are a required component of thejoining system, they shall be placed on the pipe ends, at therequired locatio
34、n on the pipe, prior to installation of the coupleror bands, or prior to stabbing a bell and spigot joint. For joiningsystems incorporating o-rings(s), the o-ring shall be placed onthe spigot end of the pipe when the joint is a stab-type joiningsystem, or one shall be placed on each end of the pipes
35、 thatform a joining system that incorporates a coupling band. If thejoining system includes a flat gasket, the gasket shall be placedover the end of the pipe previously placed and extended overthe end of the adjacent pipe after it is positioned. In lieu of asingle flat gasket, two smaller flat gaske
36、ts may be used withone gasket on the end of the pipe forming the joint. For pipesupplied with a factory installed band or coupler, no fieldinstalled gasket will be required on the pipe end with thefactory installed device. When recommended by the manufac-turer, lubricant shall be applied to the desi
37、gnated surfaces.Once installed, the gasket shall be protected against damageuntil the joint is completely installed.8.2.3.2 Coupling BandsCoupling bands shall be placedon the end of the last pipe installed. When installing two-partbands, the first portion of the band shall be placed to cover thebott
38、om portion of the pipe. When the subsequent pipe isplaced, the installation of the joining system is completed toensure proper alignment of the pipeline. The width of theopening between pipe ends shall be as recommended by thepipe fabricator. The band shall be tightened around the pipeends to the ex
39、tent necessary to achieve proper performance ofthe joining system. The band shall be placed over the pipebeing joined in a manner that matches any corrugations ordimples in the band with the corrugations in the pipe. Followthe pipe fabricators instructions and methods for tighteningthe bands.8.2.3.3
40、 Sleeve Coupler and Bell and Spigot JoiningSystemsWhen a field installed sleeve coupler is utilized, itshall be placed on the end of the pipe previously placed. Witha bell and spigot system, the first pipe is to be oriented so thebell is open in a direction in which installation will proceed.The sub
41、sequent pipe is installed by inserting the spigot, or pipeend without the sleeve coupler, to the maximum depth permit-ted by the joining system. Follow the pipe fabricators instruc-tions for the method of assembly and use of insertion force.8.2.4 Joint BackfillThe joining system was selected basedon
42、 the expected site conditions, specifically the type andgradation of backfill material. The structural backfill materialused around the pipe shall be in accordance with the projectspecifications. Backfill material shall conform to that specifiedin Section 9, and shall be placed in accordance with Se
43、ction 10.Care shall be exercised during backfill placement not todamage or dislodge the joining system.FIG. 5 Bedding and Corner Zone Treatment for Pipe-ArchStructuresB788/B788M 0939. Structural Backfill Material9.1 Structural backfill is that material that surrounds thepipe, extending laterally to
44、the walls of the trench, or to the fillmaterial for embankment construction, and extending verti-cally from the invert to an elevation of 1 ft 300 mm or18 thediameter or span, whichever is greater, over the pipe. Thenecessary width of structural backfill depends on the quality ofthe trench wall or e
45、mbankment material, the type of materialand compaction equipment used for the structural backfill, andin embankment construction, the type of construction equip-ment used to compact the embankment fill. The width ofstructural backfill shall meet the requirements given in Table 1.9.2 Structural backf
46、ill material shall be readily compactedsoil or granular fill material with no material retained on a 3-in.75-mm ring. Select materials such as bank-run gravels orother processed granular materials with excellent structuralcharacteristics are preferred. Desired end results are obtainablewith this typ
47、e of material with a minimum of compaction effortover a wide range of moisture content, lift depth, and compac-tion equipment characteristics. Excavated native soils used asstructural backfill shall not contain frozen lumps, highly plasticclay, organic material, corrosive material, or other deleteri
48、ousforeign materials. Soil classifications are defined in Classifica-tion D2487. Soils meeting the requirements of groups GW, GP,GM, GC, SW, and SP are generally acceptable, when com-pacted to the specified percent of maximum density as deter-mined by Test Method D698. Test Methods D1556, D2167,D293
49、7, and D6938 shall be used to determine the in-placedensity of the soil. Soil types SM and SC are acceptable, butthey will require closer control to obtain the specified density.Soil Groups ML and CL are not preferred materials, while soilGroups OL, MH, CH, OH, and PT are not acceptable.9.3 Special materials other than soil are acceptable whenused as described in 10.1.10. Structural Backfill Placement10.1 Structural backfill shall be placed in non-compactedlayers from 6 to 12 in. 150 to 300 mm in depth depending onthe type of material and compa
