ASTM C12-2017 pdf free download

ASTM C12-2017 pdf free download.Standard Practice for Installing Vitrified Clay Pipe Lines
1. Scope
1.1 This practice covers the proper methods of installing vitrified clay pipe lines by open trench construction methods in order to 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 mathematical conversions to SI units that are provided for information only and 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 responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations 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 the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Supporting Strength
4.1 The field supporting strength of vitrified clay pipe is materially affected by the methods of installation. The field supporting strength of a pipe is defined as its capacity to support dead and live loads under actual field conditions. It is dependent upon two factors: (1) the inherent strength of the pipe and (2) the bedding of the pipe. 4.2 The minimum bearing strength requirement in accor- dance with Specification C700, as determined by the 3-edge- bearing test ofTest Methods C301, is a measure ofthe inherent strength of the pipe. 4.3 The tests used to measure bearing strength determine relative pipe strengths but do not represent actual field condi- tions. Therefore, an adjustment called a load factor is intro- duced to convert minimum bearing strength to field supporting strength. The magnitude of the load factor depends on how the pipe is bedded. The relationship is:
5. External Loads
5.1 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 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 higher class ofbedding, 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 above the sewer pipe, 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 compac- tion and depth of cover over the pipe. Care must be used in selection of compaction methods so that the combined dead load and live load does not exceed the field supporting strength of the pipe, or cause a change in its line or grade. N OTE 1—For generally accepted criteria and methods for determining loads and supporting strengths, see Gravity Sanitary Sewer Design and Construction, Water Pollution Control Federation Manual ofPractice No. FD-5, American Society of Civil Engineers—Manuals and Report on Engineering Practice—No. 60.
6. Bedding and Encasement
6.1 Classes ofbedding and encasements for pipe in trenches are defined herein. 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 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 of1 in. (25 mm).