1、Designation: A796/A796M 10Standard Practice forStructural Design of Corrugated Steel Pipe, Pipe-Arches,and Arches for Storm and Sanitary Sewers and OtherBuried Applications1This standard is issued under the fixed designation A796/A796M; the number immediately following the designation indicates the
2、yearof original adoption or, in the case of revision, 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 Depar
3、tment of Defense.1. Scope1.1 This practice covers the structural design of corrugatedsteel pipe and pipe-arches, ribbed and composite ribbed steelpipe, ribbed pipe with metallic-coated inserts, closed rib steelpipe, composite corrugated steel pipe, and steel structural platepipe, pipe-arches, and un
4、derpasses for use as storm sewers andsanitary sewers, and other buried applications. Ribbed andcomposite ribbed steel pipe, ribbed pipe with metallic-coatedinserts, closed rib steel pipe, and composite corrugated steelpipe shall be of helical fabrication having a continuouslockseam. This practice is
5、 for pipe installed in a trench orembankment and subjected to earth loads and live loads. Itmust be recognized that a buried corrugated steel pipe is acomposite structure made up of the steel ring and the soilenvelope, and both elements play a vital part in the structuraldesign of this type of struc
6、ture. This practice applies tostructures installed in accordance with Practice A798/A798Mor A807/A807M.1.2 Corrugated steel pipe and pipe-arches shall be of annu-lar fabrication using riveted or spot-welded seams, or of helicalfabrication having a continuous lockseam or welded seam.1.3 Structural pl
7、ate pipe, pipe-arches, underpasses, andarches are fabricated in separate plates that, when assembled atthe job site by bolting, form the required shape.1.4 This specification is applicable to design in inch-poundunits asA796 or in SI units asA796M. Inch-pound units and SIunits are not necessarily eq
8、uivalent. SI units are shown inbrackets in the text for clarity, but they are the applicablevalues when the design is done per A796M.1.5 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 estab
9、lish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A760/A760M Specification for Corrugated Steel Pipe,Metallic-Coated for Sewers and DrainsA761/A761M Specification for Corrugated Steel Struc
10、turalPlate, Zinc-Coated, for Field-Bolted Pipe, Pipe-Arches,and ArchesA762/A762M Specification for Corrugated Steel Pipe,Polymer Precoated for Sewers and DrainsA798/A798M Practice for Installing Factory-Made Corru-gated Steel Pipe for Sewers and Other ApplicationsA807/A807M Practice for Installing C
11、orrugated SteelStructural Plate Pipe for Sewers and Other ApplicationsA902 Terminology Relating to Metallic Coated Steel Prod-uctsA978/A978M Specification for Composite Ribbed SteelPipe, Precoated and Polyethylene Lined for Gravity FlowSanitary Sewers, Storm Sewers, and Other Special Appli-cationsA1
12、019/A1019M Specification for Closed Rib Steel Pipewith Diameter of 36 in. 900 mm or Less, PolymerPrecoated for Sewers and DrainsA1042/A1042M Specification for Composite CorrugatedSteel Pipe for Sewers and DrainsD698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effor
13、t (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 Rubber Balloon Method1This practice is under the jurisdiction of ASTM Committee A05 on Metallic-Coated Iron and Steel
14、Products and is the direct responsibility of SubcommitteeA05.17 on Corrugated Steel Pipe Specifications.Current edition approved Nov. 1, 2010. Published January 2011. Originallyapproved in 1982. Last previous edition approved in 2006 as A796/A796M - 06.DOI: 10.1520/A0796_A0796M-10.2For referenced AS
15、TM standards, 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
16、ocken, PA 19428-2959, United States.D2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D2922 Test Methods for Density of Soil and Soil-Aggregatein Place by Nuclear Methods (Shallow Depth)3D2937 Test Method for Density of Soil in Place by theDrive-C
17、ylinder Method2.2 AASHTO Standard:4Standard Specifications for Highway Bridges2.3 FAA Standard:5AC No. 150/53205B Advisory Circular, “Airport Drain-age,” Department of Transportation, Federal AviationAdministration, 19703. Terminology3.1 General DefinitionsFor definitions of general termsused in thi
18、s practice, refer to Terminology A902. For defini-tions of terms specific to this standard, refer to 3.2.3.2 Definitions of Terms Specific to This Standard:3.2.1 arch, na pipe shape that is supported on footingsand does not have a full metal invert.3.2.2 bedding, nthe earth or other material on whic
19、h thepipe is laid, consisting of a thin layer of imported material ontop of the in situ foundation.3.2.3 haunch, nthe portion of the pipe cross sectionbetween the maximum horizontal dimension and the top of thebedding.3.2.4 invert, nthe lowest portion of the pipe cross section;also, the bottom porti
20、on of the pipe.3.2.5 pipe, na conduit having a full circular shape, or in ageneral context, all structure shapes covered by this practice.3.2.6 pipe-arch, na pipe shape consisting of an approxi-mate semi-circular top portion, small radius corners, and largeradius invert.4. Symbols4.1 The symbols use
21、d in this practice have the followingsignificance:A = required wall area, in.2/ft mm2/mm(AL) = maximum highway design axle load, lbf NCl= longitudinal live load distribution factor for pipearchesd = depth of corrugation, in. mmE = modulus of elasticity = 29 by 106lbf/in.2200 by103MPa(EL) = earth loa
22、d, lbf/ft2kPa(FF) = flexibility factor, in./lbf mm/Nfy= specified minimum yield strengthFor 6 by 2in. 150 by 50mm corrugationType 33 = 33 000 lbf/in.2225 MPaType 38 = 38 000 lbf/in.2260 MPaFor 15 by 512 in. 380 by 140mm and 16 by 6in. 400 by150mm corrugations = 44 000 lbf/in.2300 MPaFor all other co
23、rrugations = 33 000 lbf/in.2225 MPafu= specified minimum tensile strengthFor 6 by 2in. 150 by 50mm corrugationType 33 = 45 000 lbf/in.2310 MPaType 38 = 48 000 lbf/in.2330 MPaFor 15 by 1512 in. 380 by 140mm and 16 by 6in. 400 by150mm corrugations = 55 000 lbf/in.2380 MPaFor all other corrugations = 4
24、5 000 lbf/in.2310 MPafc= critical buckling stress, lbf/in.2MPah = height of cover, in. mm determined as fol-lows: (1) highwaysfrom top of pipe to topof rigid pavement, or to top of subgrade forflexible pavement; (2) railwaystop of pipeto bottom of tieH = depth of fill above top of pipe, ft mHmin= mi
25、nimum depth of fill, ft mHmax= maximum depth of fill, ft mI = moment of inertia of corrugated shape, in.4/in. mm4/mm (see Tables 2-35)(IL) = pressure from impact load, lbf/ft2kPak = soil stiffness factor = 0.22 for good side-fillmaterial compacted to 90 % of standard den-sity based on Test Method D6
26、98L1,L2,L3= loaded lengths, in. mm defined in 18.3(LL) = pressure from live load, lbf/ft2kPaP = total design load or pressure, lbf/ft2kPaPc= corner pressure, lbf/ft2kPaPf= factored crown pressure, lbf/ft2kPar = radius of gyration of corrugation, in. mm(see Tables 2-35)rc= corner radius of pipe-arch,
27、 in. mmRn= nominal resistance for each limit state, lbf/ft kN/mRf= factored resistance for each limit state, lbf/ft kN/mrl= radius at crown, in. mmS = pipe diameter or span, ft ms = pipe diameter or span, in. mm(SF) = safety factor(SS) = required seam strength, lbf/ft kN/mT = thrust in pipe wall, lb
28、f/ft kN/mTf= factored thrust in pipe wall, lbf/ft kN/mw = unit force derived from 1 ft31 m3offillmaterial above the pipe, lbf/ft3kN/m3.When actual fill material is not known, use120 lbf/ft319 kN/m3f = resistance factor3Withdrawn. The last approved version of this historical standard is referencedon
29、www.astm.org.4Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001.5Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402. Publication No. SN-050-007-00149-5.A796/
30、A796M 1025. Basis of Design5.1 The safety factors and other specific quantitative recom-mendations herein represent generally accepted design prac-tice. The design engineer should, however, determine that theserecommendations meet particular project needs.5.2 This practice is not applicable for long
31、-span structuralplate pipe or other multi-radius shapes not described herein.Such structures require additional design considerations forboth the pipe and the soil envelope. In addition to meeting allother design requirements given herein, the maximum diam-eters or spans for structures designed by t
32、his practice are asfollows:Shape Maximum Diameter or Span, ft mmpipe, arch 26 7920 mmpipe-arch, underpass 21 6400 mm5.3 This practice is not applicable for pipe with a specifiedthickness less than 0.052 in. 1.32 mm for installations underrailways and airport runways.6. Loads6.1 The design load or pr
33、essure on a pipe is comprised ofearth load (EL), live load (LL), and impact load (IL). Theseloads are applied as a fluid pressure acting on the pipeperiphery.6.2 For steel pipe buried in a trench or in an embankment ona yielding foundation, loads are defined as follows:6.2.1 The earth load (EL) is t
34、he weight of the column of soildirectly above the pipe:EL!5Hw (1)6.2.2 Live LoadsThe live load (LL) is that portion of theweight of vehicle, train, or aircraft moving over the pipe that isdistributed through the soil to the pipe.6.2.2.1 Live Loads Under HighwayLive load pressuresfor H20 highway load
35、ings, including impact effects, are:Height of Cover, ft m Live Load, lbf/ft2kPa1 0.30 1800 86.22 0.61 800 38.33 0.91 600 28.74 1.22 400 19.25 1.52 250 12.06 1.83 200 9.67 2.13 175 8.48 2.44 100 4.8over 8 over 2.44 neglect 6.2.2.2 Live Loads Under RailwaysLive load pressuresfor E80 railway loadings,
36、including impact effects, are asfollows:Height of Cover, ft m Live Load, lbf/ft2kPa2 0.61 3800 181.95 1.52 2400 114.98 2.44 1600 76.610 3.05 1100 52.712 3.66 800 38.315 4.57 600 28.720 6.10 300 14.430 9.14 100 4.8over 30 over 9.14 neglect 6.2.2.3 Values for intermediate covers shall be interpolated.
37、6.2.2.4 Live Loads Under Aircraft RunwaysBecause ofthe many different wheel configurations and weights, live loadpressures for aircraft vary. Such pressures must be determinedfor the specific aircrafts for which the installation is designed;see FAA Standard AC No. 150/5320-5B.6.2.3 Impact LoadsLoads
38、 caused by the impact of mov-ing traffic are important only at low heights of cover. Theireffects have been included in the live load pressures in 6.2.2.7. Design Method7.1 Strength requirements for wall strength, bucklingstrength, and seam strength may be determined by either theallowable stress de
39、sign (ASD) method presented in Section 8,or the load and resistance factor design (LRFD) methodpresented in Section 9. Additionally, the design considerationsin other paragraphs shall be followed for either design method.8. Design by ASD Method8.1 The thrust in the pipe wall shall be checked by thre
40、ecriteria. Each considers the joint function of the steel pipe andthe surrounding soil envelope.8.1.1 Required Wall Area:8.1.1.1 Determine the design pressure and the ring compres-sion thrust in the steel pipe wall as follows:P 5 EL 1 LL 1 IL (2)T 5PS2(3)8.1.1.2 Determine the required wall cross-sec
41、tional area.The safety factor (SF) on wall area is 2.A 5T SF!fy(4)Select from Table 2, Table 4, Table 6, Table 8, Table 10,Table 12, Table 14, Table 16, Table 18, Table 20, Table 22,Table 24, Table 26, Table 28, Table 30, Table 32,orTable 34Table 3, Table 5, Table 7, Table 9, Table 11, Table 13, Tab
42、le15, Table 17, Table 19, Table 21, Table 23, Table 25, Table 27,TABLE 1 Resistance Factors for LRFD DesignType of Pipe Limit State Resistance Factor, fHelical pipe with lock seam or fully welded seam Minimum wall area and buckling 1.00Annular pipe with spot-welded, riveted, or bolted seam Minimum w
43、all area and buckling 1.00Minimum seam strength 0.67Structural plate pipe Minimum wall area and buckling 1.00Minimum seam strength 0.67A796/A796M 103Table 29, Table 31, Table 33,orTable 35 a wall thicknessequal to or greater than the required wall area (A).8.1.2 Critical Buckling StressCheck section
44、 profile withthe required wall area for possible wall buckling. If the criticalbuckling stress fcis less than the minimum yield stress fy,recalculate the required wall area using fcinstead of fy.If s ,rk24Efuthen fc5 fu2fu248ESksrD2(5)If s .rk24Efuthen fc512ESksrD2(6)8.1.3 Required Seam Strength:8.1
45、.3.1 Since helical lockseam and welded-seam pipe haveno longitudinal seams, this criterion is not valid for these typesof pipe.8.1.3.2 For pipe fabricated with longitudinal seams (riveted,spot-welded, or bolted) the seam strength shall be sufficient todevelop the thrust in the pipe wall. The safety
46、factor on seamstrength (SS) is 3.SS!5T SF! (7)8.1.3.3 Check the ultimate seam strengths shown in Table 4,Table 6, Table 32,orTable 34,Table 5, Table 7, Table 33,orTable 35. If the required seam strength exceeds that shown forthe steel thickness already chosen, use a heavier pipe whoseseam strength e
47、xceeds the required seam strength.9. Design by LRFD Method9.1 Factored LoadsThe pipe shall be designed to resistthe following combination of factored earth load (EL) and liveload plus impact (LL + IL):Pf5 1.95 EL 1 1.75 LL 1 IL! (8)9.2 Factored ThrustThe factored thrust, Tf, per unitlength of wall s
48、hall be determined from the factored crownpressure Pfas follows:Tf5 PfS/2 (9)9.3 Factored ResistanceThe factored resistance (Rf) shallequal or exceed the factored thrust. Rfshall be calculated forthe limit states of wall resistance, resistance to buckling, andseam resistance (where applicable) as fo
49、llows:Rf5fRn(10)The resistance factor (f) shall be as specified in Table 1. Thenominal resistance (Rn) shall be calculated as specified in 9.4,9.5, and 9.6.9.4 Wall ResistanceThe nominal axial resistance per unitlength of wall without consideration of buckling shall be takenas:Rn5 fyA (11)9.5 Resistance to BucklingThe nominal resistance calcu-lated using Eq
