1、Designation: B 788/B 788M 04Standard Practice forInstalling Factory-Made Corrugated Aluminum Culverts andStorm Sewer Pipe1This standard is issued under the fixed designation B 788/B 788M; the number immediately following the designation indicates the yearof original adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) 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 desc
3、ribes 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 descr
4、ibed 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 B 790/B 790M.1.2 This practice is applicable to either
5、inch-pound units asB 788 or to SI units as B 788M. Inch-pound units are notnecessary equivalent to SI units. SI units are shown in the textin brackets, and they are the applicable values for metricinstallation.1.3 This standard does not purport to address all of thesafety concerns, if any, associate
6、d 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:2B 745/B 745M Specification for Corrugated AluminumPipe for Sew
7、ers and DrainsB 790/B 790M Practice for Structural Design of CorrugatedAluminum Pipe, Pipe Arches, and Arches for Culverts,Storm Sewers, and Other Buried ConduitsD 698 Test Method for Laboratory Compaction Character-istics of Soil Using Standard Effort (12,400 ft-lbf/ft3600kN-m/m3)D 1556 Test Method
8、 for Density and Unit Weight of Soil inPlace by the Sand-Cone MethodD 2167 Test Method for Density and Unit Weight of Soil inPlace by the Rubber-Balloon MethodD 2487 Classification of Soils for Engineering Purposes(Unified Soil Classification System)D 2922 Test Methods for Density of Soil and Soil-A
9、ggregate in Place by Nuclear Methods (Shallow Depth)D 2937 Test Method for Density of Soil in Place by theDrive-Cylinder Method3. Terminology3.1 Definitions of Terms Specific to This Standard:1This practice is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct r
10、esponsibility of Subcommittee B07.08 onAluminum Culvert.Current edition approved Oct 1, 2004. Published October 2004. Originallyapproved in 1988. Last previous edition approved in 2000 as B 788/B 788M 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Se
11、rvice 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 at the end of this standard.Copyr
12、ight ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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.
13、3.1.3 invert, nthe lowest point on the pipe cross section;also, the bottom portion of 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 corne
14、rs, and large-radius invert.4. Significance and Use4.1 Corrugated aluminum pipe functions 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 impor
15、tant to ensure that the soil structure or backfillis made up of acceptable material and is well-constructed.Field verification of soil structure acceptability using TestMethods D 1556, D 2167, D 2922, or D 2937, as applicable,and comparing the results with Test Method D 698 in accor-dance with the s
16、pecifications for each project, is the mostreliable basis for installation of an acceptable structure. Therequired density and method of measurement are not specifiedby this practice, but they must be established in the specifica-tions for each project.5. Trench Excavation5.1 To obtain anticipated s
17、tructural performance of corru-gated aluminum pipe it is not necessary to control trench widthbeyond 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 cal
18、ls for a relatively wide trench,it shall be made as wide as required, for its full depth if sodesired. 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 unifor
19、m resistance to the imposed load, bothlongitudinally and laterally. Sharp variations in the foundationmust 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
20、 pipe. See Fig. 3.6.2 Lateral changes in foundation should never be such thatthe pipe is firmly supported 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
21、 three pipe widths,unless the engineer has set another limit. See Fig. 4.6.3 Performance of buried 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 i
22、tself which willyield under load more than will the foundation under thecolumns of soil to each side. 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 move
23、ment between pipeand the soil on each side. It is of particular importance onpipe-arches.6.4 Pipe-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
24、support under their large-radiusinverts.6.5 The engineer is encouraged to develop details specific tothe site based on the general principles for foundation condi-tions given in 6.1 through 6.4.d =12 in./ft 40 mm/m of fill over pipe, with a 24-in. 600-mm maximum.NOTE 1Section B-B is applicable to al
25、l continuous rock foundations.FIG. 3 Foundation Transition Zones and Rock FoundationsFIG. 4 Soft Foundation TreatmentB 788/B 788M 0427. 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 o
26、n a 3-in. 75-mm ring,frozen lumps, chunks of highly plastic clay, organic matter,corrosive material, 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
27、fine-grade the foundation toa slight v-shape. This avoids the problem of trying to backfillthe difficult 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 ands
28、hall be prevented from striking rock or other hard objectsduring placement on bedding. Pipe with protective 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 forcorru
29、gated aluminum pipe serve several purposes: (1) tomaintain pipe alignment during installation; (2) 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 limitexfiltr
30、ation of the flow through the pipe.8.2.2 Joint System ComponentsThe joining system shallbe specified by the project engineer. The components shallconform to the requirements of Specification B 745/B 745M.The pipe fabricator shall provide the components specified forthe project or as designated by th
31、e fabricator in accordancewith Specification B 745/B 745M, Ordering Information. Con-formance of the joining 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
32、 be achieved only when allcomponents of the pipe system are properly installed. As anintegral portion of 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
33、 required component of thejoining system, they shall be placed on the pipe ends, at therequired location 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 o
34、f the pipe when the joint is a stab-type joiningsystem, or one shall be placed on each end of the pipes 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
35、end of the adjacent pipe after it is positioned. In lieu of asingle flat gasket, two smaller flat gaskets 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 the
36、factory installed device. When recommended by the manufac-turer, lubricant shall be applied to the designated 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 i
37、nstalled. When installing two-partbands, the first portion of the band shall be placed to cover thebottom 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 s
38、hall be as recommended by thepipe fabricator. The band shall be tightened around the pipeends to the extent 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 corrug
39、ations in the pipe. Followthe pipe fabricators instructions and methods for tighteningthe bands.8.2.3.3 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 fi
40、rst pipe is to be oriented so thebell is open in a direction in which installation will proceed.The subsequent 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 me
41、thod of assembly and use of insertion force.8.2.4 Joint BackfillThe joining system was selected basedon 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. B
42、ackfill material shall conform to that specifiedin Section 9, and shall be placed in accordance with Section 10.Care shall be exercised during backfill placement not todamage or dislodge the joining system.9. Structural Backfill Material9.1 Structural backfill is that material that surrounds thepipe
43、, extending laterally to the walls of the trench, or to the fillFIG. 5 Bedding and Corner Zone Treatment for Pipe-ArchStructuresB 788/B 788M 043material for embankment construction, and extending verti-cally from the invert to an elevation of 1 ft 300 mm or18 thediameter or span, whichever is greate
44、r, over the pipe. Thenecessary width of structural backfill depends on the quality ofthe trench wall or embankment 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 embankmen
45、t fill. The width ofstructural backfill shall meet the requirements given in Table 1.9.2 Structural backfill 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 material
46、s with excellent structuralcharacteristics are preferred. Desired end results are obtainablewith this type 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 sh
47、all not contain frozen lumps, highly plasticclay, organic material, corrosive material, or other deleteriousforeign materials. Soil classifications are defined in Classifica-tion D 2487. Soils meeting the requirements of groups GW,GP, GM, GC, SW, and SP are generally acceptable, whencompacted to the
48、 specified percent of maximum density asdetermined by Test Method D 698. Test Methods D 1556, D2167, D 2922, and D 2937 shall be used to determine thein-place density of the soil. Soil types SM and SC areacceptable, but they will require closer control to obtain thespecified density. Soil Groups ML
49、and CL are not preferredmaterials, while soil Groups OL, MH, CH, OH, and PT are notacceptable.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 compaction equipment or method.Each layer or lift shall be compacted before adding the nextlift. On flat bedding, care must be taken to place material underthe pipe haunches and compact it firmly. Str
