1、Designation: C12 17Standard Practice forInstalling Vitrified Clay Pipe Lines1This standard is issued under the fixed designation C12; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in parentheses
2、indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This practice covers the proper methods of installingvitrified clay pipe
3、lines by open trench construction methods inorder to fully utilize the structural properties of such pipe.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
4、 considered standard.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, health, and environmental practices and deter-mine the applicability of regulatory lim
5、itations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organizatio
6、n TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C301 Test Methods for Vitrified Clay PipeC403/C403M Test Method for Time of Setting of ConcreteMixtures by Penetration ResistanceC425 Specification for Compression Joints for Vitrified ClayPipe and FittingsC700 S
7、pecification for Vitrified Clay Pipe, Extra Strength,Standard Strength, and PerforatedC828 Test Method for Low-Pressure Air Test of VitrifiedClay Pipe LinesC896 Terminology Relating to Clay ProductsC923 Specification for Resilient Connectors Between Rein-forced Concrete Manhole Structures, Pipes, an
8、d LateralsC1091 Test Method for Hydrostatic Infiltration Testing ofVitrified Clay Pipe LinesD1586 Test Method for Standard Penetration Test (SPT) andSplit-Barrel Sampling of SoilsD2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D2488 Practice for
9、 Description and Identification of Soils(Visual-Manual Procedures)D4832 Test Method for Preparation and Testing of Con-trolled Low Strength Material (CLSM) Test CylindersD5821 Test Method for Determining the Percentage ofFractured Particles in Coarse AggregateD6103/D6103M Test Method for Flow Consis
10、tency of Con-trolled Low Strength Material (CLSM)3. Terminology3.1 GeneralTerminology C896 can be used for clarifica-tion of terminology in this specification.3.2 See Fig. 1.DESIGN CONSIDERATIONS4. Supporting Strength4.1 The field supporting strength of vitrified clay pipe ismaterially affected by t
11、he methods of installation. The fieldsupporting strength of a pipe is defined as its capacity tosupport dead and live loads under actual field conditions. It isdependent upon two factors: (1) the inherent strength of thepipe and (2) the bedding of the pipe.4.2 The minimum bearing strength requiremen
12、t in accor-dance with Specification C700, as determined by the 3-edge-bearing test of Test Methods C301, is a measure of the inherentstrength of the pipe.4.3 The tests used to measure bearing strength determinerelative pipe strengths but do not represent actual field condi-tions. Therefore, an adjus
13、tment called a load factor is intro-duced to convert minimum bearing strength to field supportingstrength. The magnitude of the load factor depends on how thepipe is bedded. The relationship is:Field supporting strength 5 minimum bearing strength 3load factor1This practice is under the jurisdiction
14、of ASTM Committee C04 on VitrifiedClay Pipe and is the direct responsibility of Subcommittee C04.20 on Methods ofTest and Specifications.Current edition approved Dec. 1, 2017. Published January 2018. Originallyapproved in 1915. Last previous edition approved in 2016 as C12 16a. DOI:10.1520/C0012-17.
15、2For referenced ASTM 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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C
16、700, 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 Standards, Guides and Recommendations issued by the
17、World Trade Organization Technical Barriers to Trade (TBT) Committee.14.4 A factor of safety 1.0 and 1.5 shall be applied to thefield supporting strength to calculate a safe supporting strength.The relationship is:Safe supporting strength 5Field supporting strengthFactor of safety5. External Loads5.
18、1 The external loads on installed vitrified clay pipe are oftwo general types: (1) dead loads and (2) live loads.5.2 For pipes installed in trenches at a given depth, the deadload increases as the trench width, measured at the top of thepipe, increases. Pipe failure may result if the design trenchwi
19、dth is exceeded. If the trench width exceeds the designwidth, a higher class of bedding, stronger pipe, or both, must beinvestigated.5.3 Live loads that act at the ground surface are partiallytransmitted to the pipe. Live loads may be produced by wheelloading, construction equipment or by compactive
20、 effort.Compaction of embedment and backfill materials, beside andabove the sewer pipe, produces a temporary live load on thepipe. The magnitude of the live load from compactive effortvaries with soil type, degree of saturation, degree of compac-tion and depth of cover over the pipe. Care must be us
21、ed inselection of compaction methods so that the combined deadload and live load does not exceed the field supporting strengthof the pipe, or cause a change in its line or grade.NOTE 1For generally accepted criteria and methods for determiningloads and supporting strengths, see Gravity Sanitary Sewe
22、r Design andConstruction, Water Pollution Control Federation Manual of Practice No.FD-5, American Society of Civil EngineersManuals and Report onFIG. 1 TerminologyC12172Engineering PracticeNo. 60.36. Bedding and Encasement6.1 Classes of bedding and encasements for pipe in trenchesare defined herein.
23、 The load factors indicated are for conver-sion of minimum bearing strength to field supporting strength.6.1.1 The soil groups used in each bedding class are definedin Table 1.6.1.2 The gradation for Class I and Class II soil for Class Cbedding (Fig. 3) shall have a maximum particle size of 1 in. (2
24、5mm).6.1.3 The gradation for Class I and Class II bedding materialfor Class B (Fig. 4), Crushed Stone Encasement (Fig. 5), andCLSM installation (Fig. 6) shall be as follows:100 % passing a 1 in. (25 mm) sieve40-60 % passing a34 in. (19 mm) sieve0-25 % passing a38 in. (9.5 mm) sieve6.1.4 For Class I,
25、 all particle faces shall be fractured.6.1.5 Class II soils shall have a minimum of one fracturedface. For Class B (Fig. 4), Crushed Stone Encasement (Fig. 5),and CLSM installations (Fig. 6) where high, or changing watertables, or both, are present; Class II material shall have aminimum percentage b
26、y particle count of one fractured face-100 %, two fractured faces-85 %, and three fractured faces-65 % in accordance with Test Method D5821.6.1.6 Class I material is considered to be more stable andprovide better support than Class II material that have somerounded edges.6.1.7 All bedding material s
27、hall be shovel-sliced so thematerial fills and supports the haunch area and encases the pipeto the limits shown in the trench diagrams.6.2 Class D (Fig. 2):6.2.1 The pipe shall be placed on a foundation with bellholes provided (Fig. 7).6.2.2 The initial backfill shall be either Class I, II, III, or
28、IVhaving a maximum particle size of 1 in. (25 mm).6.2.3 The load factor for Class D bedding is 1.1.6.3 Class C (Fig. 3):6.3.1 The pipe shall be bedded in Class I or Class II soil.Refer to 6.1.2 and Table 2 for requirements. Sand is suitable asa bedding material in a total sand environment, but may b
29、eunsuitable where high and rapidly changing water tables arepresent in the pipe zone. Sand may also be undesirable in atrench cut by blasting or in trenches through clay type soil.Regardless of the trench condition or bedding class, themaximum load factor for sand bedding is 1.5. The beddingshall ha
30、ve a minimum thickness beneath the pipe of 4 in. (100mm) or one sixth of the outside diameter of the pipe, whicheveris greater, and shall extend up the haunches of the pipe onesixth of the outside diameter of the pipe.6.3.2 The initial backfill shall be either Class I, II, III, or IVhaving maximum p
31、article size of 1-12 in. (38 mm) (see Table2).6.3.3 The load factor for Class C bedding is 1.5.6.4 Class B (Fig. 4):6.4.1 The pipe shall be bedded in Class I or Class II soil.Refer to 6.1.3, 6.1.5, and Table 2 for requirements. Thebedding shall have a minimum thickness beneath the pipe of 4in. (100
32、mm) or one sixth of the outside diameter of the pipe,whichever is greater, and shall extend up the haunches of thepipe to the springline.6.4.2 The initial backfill shall be either Class I, II, III, or IVhaving a maximum particle size of 1-12 in. (38 mm).6.4.3 The load factor for Class B bedding is 1
33、.9.3Available from American Society of Civil Engineers (ASCE), 1801 AlexanderBell Dr., Reston, VA 20191, http:/www.asce.org.TABLE 1 Uniform Soil Groups for Pipe InstallationNOTE 1Soil Classification descriptions and symbols are in accordance with Practice D2487 and Practice D2488.NOTE 2For Class I,
34、all particle faces shall be fractured.NOTE 3Materials such as broken coral, shells, slag, and recycled concrete (with less than 12 % passing a #200 sieve) should be treated as Class IIsoils.NOTE 4Class V soil is not suitable for use as a bedding or initial backfill material.Class I crushed rock100 %
35、 passing 1-12 in. (38 mm) sieve,/= 30 % retained on #200 sieveML, CLClass IV fine-grained soilsor any soil beginning with one of these symbolswith 30 % retained on #200 sieveML, CLClass V fine-grained soils, organic soilshigh compressibility silts and clays, organic soilMH, CH, OL, OH, PtC121736.5 C
36、rushed Stone Encasement (Fig. 5):6.5.1 The pipe shall be bedded in Class I or Class II soil.Refer to 6.1.3, 6.1.5, and Table 2 for requirements. Thebedding shall have a minimum thickness beneath the pipe of 4in. (100 mm) or one sixth of the outside diameter of the pipe,whichever is greater, and shal
37、l extend upward to a horizontalplane at the top of the pipe barrel. Material shall be carefullyplaced into the pipe haunches.6.5.2 Sufficient material shall be placed so that the beddingextends to a horizontal plane at the top of the pipe barrelfollowing removal of any trench sheeting or boxes.6.5.3
38、 The initial backfill shall be either Class I, II, III, or IVhaving a maximum particle size of 1-12 in. (38 mm).6.5.4 The load factor for crushed stone encasement is 2.2.6.6 Controlled Low Strength Material (Fig. 6)Controlledlow strength material (CLSM) is used as an effective materialfor the beddin
39、g of vitrified clay pipe.6.6.1 The pipe shall be bedded on Class I or Class II soil.Refer to 6.1.3, 6.1.5, and Table 2 for requirements. Thebedding shall have a minimum thickness beneath the pipe of 4in. (100 mm) or one sixth of the outside diameter of the pipe,whichever is greater.6.6.2 For pipe di
40、ameters 8 to 21 in. (205 to 535 mm), CLSMshall extend a minimum of 9 in. (230 mm) on each side of thepipe barrel. For pipe diameters 24 in. (610 mm) and larger,FIG. 2 Class DFIG. 3 Class CC12174CLSM shall extend a minimum of 12 in. (305 mm) on eachside of the pipe barrel (Fig. 6).6.6.3 When placed,
41、CLSM shall have a measured flowabil-ity of 8 6 1 in. (205 6 25 mm) spread diameter as determinedby Test Method D6103/D6103M.6.6.4 28-day compressive strength shall be 100 to 300 psi(0.69 to 2.07 MPa) as determined by Test Method D4832.6.6.5 CLSM shall be directed to the top of the pipe to flowdown e
42、qually on both sides to prevent misalignment. PlaceCLSM to the top of the pipe barrel.6.6.6 The initial backfill shall be either Class I, II, III, or IVhaving a maximum particle size of 1-12 in. (38 mm).6.6.7 Initial backfill shall only commence after a 500 psi(3.45 MPa) minimum penetrometer reading
43、 is achieved asdetermined by Test Method C403/C403M. The penetrometershall have a maximum load capability of 700 psi (4.83 MPa)and have a 1 in.2 1 in. (645 mm2 25 mm) long cylinder footattached to a14 in. (6 mm) diameter pin.6.6.8 The load factor for controlled low strength material is2.8.6.7 Concre
44、te Cradle (Fig. 8):6.7.1 The pipe shall be bedded in a cradle of reinforcedconcrete having a thickness under the barrel of at least 6 in.(150 mm) or one fourth of the outside diameter of the pipe,whichever is greater, and extending up the haunches to a heightof at least one half the outside diameter
45、 of the pipe. The cradlewidth shall be at least equal to the outside diameter of the pipeplus 4 in. (100 mm) on each side or one and one fourth timesthe outside diameter of the pipe, whichever is greater. If thetrench width is greater than either of these dimensions,concrete may be placed to full tr
46、ench width.6.7.2 The initial backfill shall be either Class I, II, III, or IVhaving a maximum particle size of 1-12 in. (38 mm).6.7.3 The load factor for Class A concrete cradle bedding is3.4 for reinforced concrete with p = 0.4 %, where p is theFIG. 4 Class BFIG. 5 Crushed Stone EncasementC12175per
47、centage of the area of transverse steel to the area of concreteat the bottom of the pipe barrel as shown in Fig. 8.6.8 Concrete Encasement:6.8.1 There are specific sites where concrete encasementmay be desirable. Concrete encasement shall completely sur-round the pipe and shall have a minimum thickn
48、ess, at anypoint, of one fourth of the outside diameter of the pipe or 4 in.(100 mm), whichever is greater.6.8.2 The encasement shall be designed by the engineer tosuit the specific use.6.9 Construction joints shall be installed in concrete cradleor concrete encasement construction. These joints sha
49、ll bealigned with the face of the socket.CONSTRUCTION TECHNIQUES7. Trench Excavation7.1 Trenches shall be excavated to a width that will provideadequate working space, but not more than the maximumdesign width. Trench walls shall not be undercut.7.2 The trench walls can be sloped to reduce trench wallfailure. This sloping will not increase the load on the pipeprovided the measured trench width at top of pipe does notexceed the design trench width.7.3 Trenches, other than for Class D bedding, shall beexcavated to provide space for th
