1.1 本规程涵盖了地下预制混凝土公用设施结构的规划、现场准备和安装过程中应遵循的程序。本规程不包括混凝土管涵和箱涵。此外，规范中涵盖了预制混凝土人孔 C478/C478M 被排除在本惯例之外。 1.2 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

1.1 This practice covers the procedures to be followed in the planning, site preparation, and installation of underground precast concrete utility structures. Concrete pipe and box culverts are not covered under this practice. Also, precast concrete manholes covered in Specification C478/C478M are excluded from this practice. 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 appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.