1、Designation: C12 16aC12 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 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 by open trench construction methods in orderto fully utilize the structural properties of 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 a
4、nd are not considered standard.1.3 This 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 safety, health, and healthenvironmental practices and determine theapplicabil
5、ity of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World
6、Trade Organization Technical Barriers 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 Concrete Mixtures by Penetration ResistanceC425 Specification for Compression Joints for Vitrified Clay Pip
7、e and FittingsC700 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 ProductsC923 Specification for Resilient Connectors Between Reinforced Concrete Manhole
8、Structures, Pipes, and LateralsC1091 Test Method for Hydrostatic Infiltration Testing of Vitrified Clay Pipe LinesD1586 Test Method for Standard Penetration Test (SPT) and Split-Barrel Sampling of SoilsD2487 Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification S
9、ystem)D2488 Practice for Description and Identification of Soils (Visual-Manual Procedures)D4832 Test Method for Preparation and Testing of Controlled Low Strength Material (CLSM) Test CylindersD5821 Test Method for Determining the Percentage of Fractured Particles in Coarse AggregateD6103D6103/D610
10、3M Test Method for Flow Consistency of Controlled Low Strength Material (CLSM)3. Terminology3.1 GeneralTerminology C896 can be used for clarification of terminology in this specification.3.2 See Fig. 1.1 This practice is under the jurisdiction of ASTM Committee C04 on Vitrified Clay Pipe and is the
11、direct responsibility of Subcommittee C04.20 on Methods of Test andSpecifications.Current edition approved Nov. 1, 2016Dec. 1, 2017. Published November 2016January 2018. Originally approved in 1915. Last previous edition approved in 2016 asC12 16.C12 16a. DOI: 10.1520/C0012-16A.10.1520/C0012-17.2 Fo
12、r referencedASTM standards, visit theASTM website, www.astm.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.This document is not an ASTM standard and is intended only to pro
13、vide 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 only the current versionof the
14、 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 States1DESIGN CONSIDERATIONS4. Supporting Strength4.1 The field supporting strength of vitrified clay pipe is materially
15、 affected by the methods of installation. The field supportingstrength of a pipe is defined as its capacity to support dead and live loads under actual field conditions. It is dependent upon twofactors: (1) the inherent strength of the pipe and (2) the bedding of the pipe.4.2 The minimum bearing str
16、ength requirement in accordance with Specification C700, 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.There
17、fore, an adjustment called a load factor is introduced to 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
18、1.5 shall be applied to the field supporting strength to calculate a safe supporting strength. Therelationship is:FIG. 1 TerminologyC12 172Safe supporting strength5Field supporting strengthFactor of safety5. External Loads5.1 The external loads on installed vitrified clay pipe are of two general typ
19、es: (1) dead loads and (2) live loads.5.2 For pipes installed in trenches at a given 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 highercl
20、ass of bedding, stronger pipe, or both, must be investigated.5.3 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 abo
21、ve the sewerpipe, produces a temporary live load on the pipe. 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 an
22、d live load does not exceed the field supporting strength 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
23、of Practice No. FD-5, American Society of Civil EngineersManuals and Report onEngineering PracticeNo. 60.36. 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 support
24、ing strength.6.1.1 The soil groups used in each bedding class 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), C
25、rushed Stone Encasement (Fig. 5), andCLSM installation (Fig. 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.3 Available from American Society of Civil Engin
26、eers (ASCE), 1801 Alexander Bell 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, all particle faces shall be fractured.NOTE 3Mater
27、ials 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 % passing 1-12 in. (38 mm) sieve,/= 30 % retained
28、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, PtC12 1736.1.5 Class II soils shall have a minimum of one frac
29、tured face. For Class B (Fig. 4), Crushed Stone Encasement (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 fracture
30、d faces-65 % in accordancewith Test Method D5821.6.1.6 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 p
31、ipe to thelimits shown in the trench diagrams.6.2 Class D (Fig. 2):6.2.1 The pipe shall be placed on a firm and unyielding trench bottom foundation 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
32、.3 The load factor for Class D bedding is 1.1.6.3 Class C (Fig. 3):FIG. 2 Class DFIG. 3 Class CC12 1746.3.1 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 as abedding material in a total sand environment, but may be unsuitable wher
33、e high and rapidly changing water tables are present inthe pipe zone. Sand may also be undesirable in a trench cut by blasting or in trenches through clay type soil. Regardless of thetrench condition or bedding class, the maximum load factor for sand bedding is 1.5. The bedding shall have a minimum
34、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 the pipe.6.3.2 The initial backfill shall be either Class I, II, III, or IV having maximum particle siz
35、e of 1-12 in. (38 mm) (see Table 2).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. The bedding shallhave a minimum thickness beneath the pipe of 4 in. (100 mm) or o
36、ne 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 of 1-12 in. (38 mm).6.4.3 The load factor for Class B bedding is 1.9.6.5
37、 Crushed Stone Encasement (Fig. 5):FIG. 4 Class BFIG. 5 Crushed Stone EncasementC12 1756.5.1 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 shallhave a minimum thickness beneath the pipe of 4 in. (100 mm) or one sixth of the out
38、side 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.6.5.2 Sufficient material shall be placed so that the bedding extends to a horizontal plane at the top of the pipe ba
39、rrel 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 Strength Material (Fig. 6)Controlled low strength m
40、aterial (CLSM) is used as an effective material forthe bedding 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. The bedding shallhave a minimum thickness beneath the pipe of 4 in. (100 mm) or one sixth of the outs
41、ide diameter of the pipe, whichever is greater.6.6.2 For pipe diameters 8 to 21 in. (205 to 535 mm), CLSM shall extend a minimum of 9 in. (230 mm) on each side of thepipe barrel. For pipe diameters 24 in. (610 mm) and larger, CLSM shall extend a minimum of 12 in. (305 mm) on each side ofthe pipe bar
42、rel (Fig. 6).6.6.3 When placed, CLSM shall have a measured flowability of 861 in. (205625 mm) spread diameter as determined by TestMethod D6103D6103/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.This type of construction requir
43、es 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 Strength Material (CLSM)FIG. 7 Uniform Pipe SupportC12 1766.6.5 CLSM shall be
44、 directed to the top of the pipe to flow down equally on both sides to prevent misalignment. Place CLSMto the top of the pipe barrel.6.6.6 The initial backfill shall be either Class I, II, III, or IV having a maximum particle size of 1-12 in. (38 mm).6.6.7 Initial backfill shall only commence after
45、a 500 psi (3.45 MPa) minimum penetrometer reading is achieved as determinedby Test Method C403/C403M. The penetrometer shall have a maximum load capability of 700 psi (4.83 MPa) and have a 1 in.2 1in. (645 mm2 25 mm) long cylinder foot attached to a 14 in. (6 mm) diameter pin.6.6.8 The load factor f
46、or controlled low strength material is 2.8.6.7 Concrete Cradle (Fig. 8):TABLE 2 Allowable Bedding Material and Initial Backfill Per Bedding ClassBedding Class Allowable Bedding Material Allowable Initial BackfillClassTable 1Gradation Maximum Particle Size ClassTable 1Maximum Particle SizeClass D N/A
47、 N/A N/A I, II, III, or IV 1 in. (25 mm)Class C I or II 1 in. (25 mm) I, II, III, or IV 1-12 in. (38 mm)Class BI or II 100 % passing a 1 in.(25 mm) sieve1 in. (25 mm) I, II, III, or IV 1-12 in. (38 mm)40-60 % passing a 34in. (19 mm) sieve0-25 % passing a 38 in.(9.5 mm) sieveCrushedStoneEncasementI o
48、r II 100 % passing a 1 in.(25 mm) sieve1 in. (25 mm) I, II, III, or IV 1-12 in. (38 mm)40-60% passing a 34 in.(19 mm) sieve0-25% passing a 38 in.(9.5 mm) sieveCLSMI or II 100 % passing a 1 in.(25 mm) sieve1 in. (25 mm) I, II, III, or IV 1-12 in. (38 mm)40-60 % passing a 34in. (19 mm) sieve0-25 % pas
49、sing a 38 in.(9.5 mm) sieveConcreteCradleN/A N/A N/A I, II, III, or IV 1-12 in. (38 mm)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 uniformly distributed small diameter rebar be used in allconcrete design.)FIG. 8 Concrete CradleC12 1776.7.1 The pipe shall be bedded in a cradle of reinforced concrete having a thickness under the barrel of at least 6 in. (150 mm)or one fourth of the outside diameter of the
