1、Designation: C12 13aC12 14Standard 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 paren
2、theses 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 installing vitrified cl
3、ay pipe lines in order to fully utilize the structural propertiesof such pipe.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered standard.1.3 T
4、his standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Document
5、s2.1 ASTM Standards:2C301 Test Methods for Vitrified Clay PipeC403/C403M Test Method for Time of Setting of Concrete Mixtures by Penetration ResistanceC425 Specification for Compression Joints for Vitrified Clay Pipe and FittingsC684 Test Method for Making, Accelerated Curing, and Testing Concrete C
6、ompression Test Specimens (Withdrawn 2012)3C700 Specification for Vitrified Clay Pipe, Extra Strength, Standard Strength, and PerforatedC828 Test Method for Low-Pressure Air Test of Vitrified Clay Pipe LinesC896 Terminology Relating to Clay ProductsC1091 Test Method for Hydrostatic Infiltration Test
7、ing of Vitrified Clay Pipe LinesD2487 Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System)D2488 Practice for Description and Identification of Soils (Visual-Manual Procedure)D4832 Test Method for Preparation and Testing of Controlled Low Strength Materia
8、l (CLSM) Test CylindersD5821 Test Method for Determining the Percentage of Fractured Particles in Coarse AggregateD6103 Test Method for Flow Consistency of Controlled Low Strength Material (CLSM) (Withdrawn 2013)33. Terminology3.1 GeneralTerminology C896 can be used for clarification of terminology
9、in this specification.DESIGN CONSIDERATIONS3.2 See Fig. 1.DESIGN CONSIDERATIONS4. Supporting Strength4.1 The field supporting strength of vitrified clay pipe is materially affected by the methods of installation. The field supportingstrength of a pipe is defined as its capacity to support dead and l
10、ive loads under actual field conditions. It is dependent upon twofactors: (1) the inherent strength of the pipe and (2) the bedding of the pipe.1 This practice is under the jurisdiction of ASTM Committee C04 on Vitrified Clay Pipe and is the direct responsibility of Subcommittee C04.20 on Methods of
11、 Test andSpecifications.Current edition approved Dec. 1, 2013Sept. 1, 2014. Published December 2013October 2014. Originally approved in 1915. Last previous edition approved in 2013 asC12 13.C12 13a. DOI: 10.1520/C0012-13A.10.1520/C0012-14.2 For referencedASTM standards, visit theASTM website, www.as
12、tm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standar
13、d and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases o
14、nly the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2 The minimum bearing strength requirement in accordance with Specification C700,
15、as determined by the 3-edge-bearing testof Test Methods C301, is a measure of the inherent strength of the pipe.4.3 The tests used to measure bearing strength determine relative pipe strengths but do not represent actual field conditions.Therefore, an adjustment called a load factor is introduced to
16、 convert minimum bearing strength to field supporting strength. Themagnitude of the load factor depends on how the pipe is bedded. The relationship is:Field supporting strength5minimum bearing strength3load factor4.4 Afactor of safety 1.0 and 1.5 shall be applied to the field supporting strength to
17、calculate a safe supporting strength. Therelationship is:Safe supporting strength5Field supporting strengthFactor of safety5. External Loads5.1 The external loads on installed vitrified clay pipe are of two general types: (1) dead loads and (2) live loads.5.2 For pipes installed in trenches at a giv
18、en depth, the dead load increases as the trench width, measured at the top of the pipe,increases. Pipe failure may result if the design trench width is exceeded. If the trench width exceeds the design width, a higherclass of bedding, stronger pipe, or both, must be investigated.FIG. 1 TerminologyC12
19、 1425.3 Live loads that act at the ground surface are partially transmitted to the pipe. Live loads may be produced by wheel loading,construction equipment or by compactive effort. Compaction of embedment and backfill materials, beside and above the sewerpipe, produces a temporary live load on the p
20、ipe. The magnitude of the live load from compactive effort varies with soil type,degree of saturation, degree of compaction and depth of cover over the pipe. Care must be used in selection of compaction methodsso that the combined dead load and live load does not exceed the field supporting strength
21、 of the pipe, or cause a change in itsline or grade.NOTE 1For generally accepted criteria and methods for determining loads and supporting strengths, see Gravity Sanitary Sewer Design andConstruction, Water Pollution Control Federation Manual of Practice No. FD-5, American Society of Civil Engineers
22、Manuals and Report onEngineering PracticeNo. 60.46. Bedding and Encasement6.1 Classes of bedding and encasements for pipe in trenches are defined herein. The load factors indicated are for conversionof minimum bearing strength to field supporting strength.6.1.1 The soil groups used in each bedding c
23、lass are defined in Table 1.6.1.2 The gradation for Class I and Class II soil for Class C bedding (Fig. 3) shall have a maximum particle size of 1 in. (25mm).6.1.3 The gradation for Class I and Class II bedding material for Class B (Fig. 4), Crushed Stone Encasement (Fig. 5), andCLSM installation (F
24、ig. 6) shall be as follows:100 % passing a 1 in. (25 mm) sieve40-60 % passing a 34 in. (19 mm) sieve0-25 % passing a 38 in. (9.5 mm) sieve6.1.4 For Class I, all particle faces shall be fractured.6.1.5 Class II soils shall have a minimum of one fractured face. For Class B (Fig. 4), Crushed Stone Enca
25、sement (Fig. 5), andCLSM installations (Fig. 6) where high, or changing water tables, or both, are present; Class II material shall have a minimumpercentage by particle count of one fractured face-100 %, two fractured faces-85 %, and three fractured faces-65 % in accordancewith Test Method D5821.6.1
26、.6 Class I material is considered to be more stable and provide better support than Class II material that have some roundededges.6.1.7 All bedding material shall be shovel-sliced so the material fills and supports the haunch area and encases the pipe to thelimits shown in the trench diagrams.4 Avai
27、lable from American Society of Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http:/www.asce.org.Minimum width of concrete cradle: Bc + 8 in. (205 mm) or 1-14 Bc.p is the ratio of the area of steel to the area of concrete. (It is recommended that wire mesh reinforcement or unifor
28、mly distributed small diameter rebar be used in allconcrete design.)FIG. 78 Concrete CradleC12 1436.2 Class D (Fig. 2): The pipe shall be placed on a firm and unyielding trench bottom with bell holes provided (Fig. 8). Theinitial backfill shall be of selected material (Note 2).6.2.1 The pipe shall b
29、e placed on a firm and unyielding trench bottom with bell holes provided (Fig. 7).6.2.2 The initial backfill shall be either Class I, II, III, or IV having a maximum particle size of 1 in. (25 mm).6.2.3 The load factor for Class D bedding is 1.1.NOTE 2Selected material is finely divided material fre
30、e of debris, organic material, and large stones.6.3 Class C (Fig. 3): The pipe shall be bedded in clean coarse-grained gravels and sands as defined in Practice D2487, Table1, (types SW, SP, GW, GP) (Note 4). Angular, non-consolidating bedding material not subject to migration may be specified (asin
31、Note 3). The bedding shall have a minimum thickness beneath the pipe of 4 in. (100 mm) or one sixth of the outside diameterof the pipe, whichever is greater, and shall extend up the haunches of the pipe one sixth of the outside diameter of the pipe. Theinitial backfill shall be of selected material
32、(Note 2).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, all particle faces shall be fractured.NOTE 3Materials such as broken coral, shells, slag, and recycled concrete (wi
33、th 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 % passing 1-12 in. (38 mm) sieve, /= 30 % retained on #200 sieveML, CLClass IV fine-grained soilsor any soil beginni
34、ng with one of these symbols with/= 30 % retained on #200 sieveML, CLClass V fine-grained soils, organic soilshigh compressibility silts and clays, organic soilMH, CH, OL, OH, PtFIG. 2 Class DC12 1446.3.1 The pipe shall be bedded in Class I or Class II soil. Refer to 6.1.2 and Table 2 for requiremen
35、ts. Sand is suitable as abedding material in a total sand environment, but may be unsuitable where high and rapidly changing water tables are present inthe pipe zone. It may also be undesirable in a trench cut by blasting or in trenches through clay type soil. Regardless of the trenchcondition or be
36、dding class, the maximum load factor for Class C sand bedding is 1.5. The bedding shall have a minimum thicknessbeneath the pipe of 4 in. (100 mm) or one sixth of the outside diameter of the pipe, whichever is greater, and shall extend up thehaunches of the pipe one sixth of the outside diameter of
37、the pipe.NOTE 3Suitable material is well-graded 34 to 14 in. (19 to 6.4 mm) crushed stone, having a minimum of one fractured face, or other angular,non-consolidating bedding material not subject to migration. Where high or changing water tables, or both, are present in the pipe zone, this material s
38、hallhave a minimum percentage by particle count of one fractured face-100 %, two fractured faces-85 %, and three fractured faces-65 % in accordance withTest Mehod D5821. Well-graded angular, non-consolidating bedding materials are more stable than rounded bedding materials of equal gradation.Materia
39、l shall be shovel-sliced so the material fills and supports the haunch area and encases the pipe to the limits shown in the trench diagrams (Figs.3-6).NOTE 4Sand is suitable as a bedding material in a total sand environment but may be unsuitable where high and rapidly changing water tables arepresen
40、t in the pipe zone. It may also be undesirable in a trench cut by blasting or in trenches through clay type soil. Regardless of the trench conditionor bedding class, the maximum load factor for sand bedding is 1.5.6.3.2 The initial backfill shall be either Class I, II, III, or IV having maximum part
41、icle size of 1-12 in. (38 mm) (see Table 2).6.3.3 The load factor for Class C bedding is 1.5.FIG. 3 Class CFIG. 4 Class BC12 1456.4 Class B (Fig. 4): The pipe shall be bedded in suitable material (Note 3). The bedding shall have a minimum thicknessbeneath the pipe of 4 in. (100 mm) or one sixth of t
42、he outside diameter of the pipe, whichever is greater, and shall extend up thehaunches of the pipe to the springline. The initial backfill shall be of selected material (Note 2).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. The beddi
43、ng shallhave a minimum thickness beneath the pipe of 4 in. (100 mm) or one sixth of the outside diameter of the pipe, whichever is greater,and shall extend up the haunches of the pipe to the springline.6.4.2 The initial backfill shall be either Class I, II, III, or IV having a maximum particle size
44、of 1-12 in. (38 mm).6.4.3 The load factor for Class B bedding is 1.9.6.5 Crushed Stone Encasement (Fig. 5): There are specific sites where crushed stone encasement may be desirable. Thecrushed stone shall extend to the specified trench width and shall have a minimum thickness beneath the pipe of 4 i
45、n. (100 mm)FIG. 5 Crushed Stone EncasementThis type of construction requires the fill to extend from the pipe to the trench wall, not to extend above the top of the pipe or below the bottom of the pipe. Where nativesoils are expansive, further investigation may be necessary.FIG. 6 Controlled Low Str
46、ength Material (CLSM)C12 146or one sixth of the outside diameter of the pipe, whichever is greater, and shall extend upward to a horizontal plane at the top ofthe pipe barrel (see Note 5). Encasement shall consist of well-graded 34 to 14 in. (19 to 6.4 mm) crushed stone or othernon-consolidating bed
47、ding material not subject to migration. Material shall be carefully placed into the pipe haunches (Note 3).The initial backfill shall be of selected material (Note 2).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. The bedding shallhav
48、e a minimum thickness beneath the pipe of 4 in. (100 mm) or one sixth of the outside diameter of the pipe, whichever is greater,and shall extend upward to a horizontal plane at the top of the pipe barrel. Material shall be carefully placed into the pipe haunches.NOTE 5Sufficient crushed stone or oth
49、er suitable material (Note 3) shall be placed so that the bedding extends to a horizontal plane at the top of thepipe barrel following removal of any trench sheeting or boxes.6.5.2 Sufficient material shall be placed so that the bedding extends to a horizontal plane at the top of the pipe barrel followingremoval of any trench sheeting or boxes.6.5.3 The initial backfill shall be either Class I, II, III, or IV having 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 Strengt
