1、Designation: F2787 13 (Reapproved 2018)Standard Practice forStructural Design of Thermoplastic Corrugated WallStormwater Collection Chambers1This standard is issued under the fixed designation F2787; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase 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. Scope*1.1 This practice standardizes structural design of thermo-plastic corrugated wall arch-shap
3、ed chambers used forcollection, detention, and retention of stormwater runoff. Thepractice is for chambers installed in a trench or bed andsubjected to earth and live loads. Structural design includes thecomposite system made up of the chamber arch, the chamberfoot, and the soil envelope. Relevant r
4、ecognized practicesinclude design of thermoplastic culvert pipes and design offoundations.1.2 This practice standardizes methods for manufacturers ofburied thermoplastic structures to design for the time depen-dent behavior of plastics using soil support as an integral partof the structural system.
5、This practice is not applicable tothermoplastic structures that do not include soil support as acomponent of the structural system.1.3 This practice is limited to structural design and does notprovide guidance on hydraulic, hydrologic, or environmentaldesign considerations that may need to be addres
6、sed forfunctional use of stormwater collection chambers.1.4 Stormwater chambers are most commonly embedded inopen graded, angular aggregate which provide both structuralsupport and open porosity for water storage. Should soils otherthan open graded, angular aggregate be specified forembedment, other
7、 installation and functional concerns mayneed to be addressed that are outside the scope of this practice.1.5 Chambers are produced in arch shapes to meet classifi-cations that specify chamber rise, chamber span, minimum footwidth, minimum wall thickness, and minimum arch stiffnessconstant. Chambers
8、 are manufactured with integral footings.1.6 Polypropylene chamber classifications are found inSpecification F2418. Specification F2418 also specifies cham-ber manufacture and qualification.1.7 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are m
9、athematicalconversions to SI units that are provided for information onlyand are not considered standard.1.8 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, he
10、alth, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.9 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Intern
11、ational Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D2990 Test Methods for Te
12、nsile, Compressive, and FlexuralCreep and Creep-Rupture of PlasticsD6992 Test Method for Accelerated Tensile Creep andCreep-Rupture of Geosynthetic Materials Based on Time-Temperature Superposition Using the Stepped IsothermalMethodF2418 Specification for Polypropylene (PP) Corrugated WallStormwater
13、 Collection Chambers2.2 AASHTO LRFD Bridge Design Specifications:3Section 3 Loads and Load Factors, 3.5 Permanent Loads; 3.6Live LoadsSection 10 Foundations, 10.6 Spread FootingsSection 12 Buried Structures and Tunnel Liners, 12.12Thermoplastic Pipes1This practice is under the jurisdiction of ASTM C
14、ommittee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.65 on LandDrainage.Current edition approved Feb. 1, 2018. Published March 2018. Originallyapproved in 2009. Last previous edition approved in 2013 as F278713. DOI:10.1520/F2787-13R18.2For referenced ASTM stand
15、ards, visit the ASTM website, www.astm.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.3AASHTO LRFD Bridge Design Specifications-Dual Units, 4th Edition, 2007and AASHTO Stand
16、ard Specifications for Transportation Materials and Sampling,28th edition, 2008. Available from American Association of State Highway andTransportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249,Washington, DC 20001.*A Summary of Changes section appears at the end of this standardCopyrigh
17、t ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International
18、 Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.12.3 AASHTO Standard Specifications:3M43Standard Specification for Size of Aggregate for Roadand Bridge ConstructionM 145 Standard Specification for Classification of Soils andSo
19、il-Aggregate Mixtures for Highway Construction Pur-posesT99Standard Method of Test for Moisture-Density Rela-tions of Soils Using a 2.5-kg (5.5-lb) Rammer and a305-mm (12-in.) Drop2.4 AWWA Manual:4M45Manual of Water Supply Practices: Fiberglass PipeDesign3. Terminology3.1 Definitions:3.1.1 Definitio
20、ns used in this specification are in accordancewith the definitions in Terminology F412, and abbreviationsare in accordance with Terminology D1600, unless otherwiseindicated.3.1.2 chamberan arch-shaped structure manufactured ofthermoplastic with an open-bottom that is supported on feetand may be joi
21、ned into rows that begin with, and are termi-nated by, end caps (see Fig. 1).3.1.3 classificationthe chamber model specification thatidentifies nominal height, nominal width, rise, span, minimumfoot width, wall thickness, and arch stiffness constant.3.1.4 corrugated walla wall profile consisting of
22、a regularpattern of alternating crests and valleys connected by webelements (see Fig. 2).3.1.5 crestthe element of a corrugation located at theexterior surface of the chamber wall, spanning between twoweb elements (see Fig. 2).3.1.6 crownthe center section of a chamber typicallylocated at the highes
23、t point as the chamber is traversedcircumferentially.3.1.7 embedmentbackfill material against the sides ofchambers and end caps and in between rows of chambers fromthe foundation stone below to a specified dimension over thetop of the chambers (see Fig. 3).3.1.8 end capa bulkhead provided to begin a
24、nd terminatea chamber, or row of chambers, and prevent intrusion ofsurrounding embedment materials.3.1.9 foota flat, turned out section that is manufacturedwith the chamber to provide a bearing surface for transfer ofvertical loads to the foundation (see Fig. 1).3.1.10 foot areathe actual contact ar
25、ea of the foot with thefoundation.3.1.11 local bucklingcompression failure of built-up platesections with high width-to-thickness ratios.3.1.12 nominal heighta designation describing the ap-proximate outside vertical dimension of the chamber at itscrown (see Fig. 1).3.1.13 nominal widtha designation
26、 describing the ap-proximate outside horizontal dimension of the chamber at itsfeet (see Fig. 1).3.1.14 risethe vertical distance from the chamber base(bottom of the chamber foot) to the inside of a chamber wallvalley element at the crown as depicted in Fig. 1.3.1.15 spanthe horizontal distance from
27、 the interior ofone sidewall valley element to the interior of the other sidewallvalley element as depicted in Fig. 1.3.1.16 valleythe element of a corrugation located at theinterior surface of a chamber wall, spanning between two webelements (see Fig. 2).3.1.17 viscoelasticitythe response of a mate
28、rial to loadthat is dependent both on load magnitude (elastic) and load rate(viscous).3.1.18 webthe element of a corrugated wall that connectsa crest element to a valley element (see Fig. 2).4. Significance and Use4.1 This practice provides a rational method for structuraldesign of thermoplastic sto
29、rmwater chambers. The loads,4AWWA Manual of Water Supply Practices M45: Fiberglass Pipe Design, 2ndEdition, 2005. Available from the American Water Works Association (AWWA),6666 W. Quincy Ave., Denver, CO 80235.NOTE 1The model chamber shown in this standard is intended only as a general illustration
30、.FIG. 1 Chamber Terminology (Typical)F2787 13 (2018)2capacities, and limit states are based on accepted load andresistance factor design for thermoplastic pipes; however,existing design specifications for thermoplastic pipes do notadequately address the design of chambers due to (1) open-bottom geom
31、etry, (2) support on integral foot, (3) varyingcircumferential corrugation geometry, and (4) manufacturewith alternative thermoplastic resin. This practice standardizesrecommendations for designers to adequately address theseaspects of chamber design.4.2 This practice is written to allow chamber man
32、ufacturersto evaluate chambers meeting existing classifications and todesign chambers for new classifications as they are developed.5. Basis of Design5.1 Design is based on AASHTO LRFD Bridge DesignSpecifications and publications for static soil-structure-interaction analysis for thermoplastic pipes
33、. Users shouldverify that these recommendations meet particular projectneeds.5.2 Chamber installations shall be designed for the criticalcombination of live load and dead load, see Section 7.5.3 Chambers shall be designed for service limit states andsafety against structural failure, see Section 8.5
34、.3.1 Service Limit StateService design shall limit verticaldisplacements at the ground surface. Chambers shall be evalu-ated for detrimental structural deformation.5.3.2 Safety Against Structural FailureStructural designshall evaluate chambers for buckling, compression, tension,and foundation bearin
35、g.5.4 Buckling capacity is based on material stress limits.Compression and tension capacities are based on materialstrain limits. Foundation bearing capacity is based on soilultimate bearing capacity.5.5 Chambers shall be designed using closed-form solutions(verified by analysis) or finite element a
36、nalysis (FEA). Designsshall be validated by testing.NOTE 1The soil-chamber system complexity generally precludes theuse of closed-form solutions for determination of design force effects.While specific solutions may be developed for individual chambergeometries, general solutions have not been devel
37、oped to accuratelypredict behavior for the many possible variations in chamber geometry. Inmost cases FEA must be employed to calculate design force effects on thechamber or as verification of closed-form solutions.5.6 Chamber material properties shall be based on tests.5.7 Chamber section propertie
38、s shall be calculated from thegeometry of the chamber cross-section.NOTE 1The corrugation profile shown in this standard is intended only as a general illustration.FIG. 2 Corrugation Terminology (Typical)FIG. 3 Installation Terminology (Typical)F2787 13 (2018)35.8 Soil properties shall be based on g
39、enerally acceptedpublished properties for the specified soil classifications or bytests on site-specific materials.6. Analysis for Design6.1 The design shall include structural modeling of thechamber under loads in the installed soil environment.Analysismodels shall include critical anticipated live
40、 loads and soilcover heights that provide deflections for serviceability designand force effects to design for safety against structural failure.6.2 Analysis shall consider the following:6.2.1 Chamber StructureTwo-dimensional FEA shall usebeam elements with effective section properties to model thec
41、hamber wall. Each beam element shall represent not morethan 10 degrees of the chamber circumference. Nodes at beamends shall be located at the center of the gravity (cg) of thecorrugated chamber wall cross-section. Three-dimensionalFEA shall employ shell elements.6.2.2 FEA ProgramAcceptable FEA prog
42、rams include (1)CANDE (Culvert Analysis and Design), (2) similarly featuredand verified culvert design software, or (3) general purposefinite element analysis software with capability to modelnonlinear static soil-structure-interaction.6.2.3 CreepThe time-dependent response (creep) of ther-moplastic
43、 chamber materials shall be included in the analysis.Acceptable methods are (1) multiple linear-elastic models withsuccessive stiffness reductions for creep effects, and (2) non-linear chamber models that include the creep response. Valuesof creep modulus shall be determined by test in accordancewit
44、h Test Methods D2990 or Test Method D6992.6.2.4 SoilModels shall include accurate representation ofthe structural backfill envelope and boundary conditions. Thebackfill envelope includes foundation, embedment, and cover.Boundary conditions typically include the size of the soilembedment zone, distan
45、ce to trench walls, subgrade under thebackfill envelope, weight and stiffness of soils above thebackfill envelope, and boundary for application of live loads.Structural backfill soils shall be modeled with nonlinearproperties that incorporate the effects of confinement. Accept-able soil models inclu
46、de (1) soil hardening models that increasesoil stiffness for confinement, (2) elastic-plastic models thatallow failure in shear, or (3) large-deformation models. Soilsoutside the backfill envelope and further than two times thechamber span from the chamber may be modeled as linear-elastic. Soil cont
47、inuum elements shall be either fully bonded tothe chamber beam elements or modeled with a friction inter-face.6.2.5 Live LoadModels shall include live loads, see Sec-tion 7.6.2.6 Chamber BedsStructural effects of adjacent cham-bers shall be analyzed. When two-dimensional plane-strainanalysis is used
48、, changes in geometry along the length ofchamber runs, including intermediate stiffeners or diaphragms,shall be addressed using separate models.7. Structural Loads7.1 The design load on a chamber shall include dead loadand live load.7.2 Dead Load (DL)Dead load shall be computed frompermanent soil co
49、ver over chambers. The soil unit weight shallnot be less than 120 lb/ft3(18.9 kN/m3) unless otherwisedetermined by tests. Dead load shall be calculated for eachinstallation.7.3 Dead Load Factor (DL)The dead load factor shall be1.95.7.4 Live Load (LL)Live load calculation is provided inAnnex A1. Live load includes transient loads (passing ve-hicles) or sustained loads (stationary non-permanent loads).Live load computation is based on theAASHTO HL-93 designvehicular live load applied to a single-loaded lane.7.4.1 HL-93The HL-93 load is a combination o
