1.1 本规程规范了用于收集、滞留和保留雨水径流的热塑性波纹墙拱形室的结构设计。这种做法适用于安装在沟槽或河床中并承受土壤和活荷载的腔室。结构设计包括由室拱、室脚和土壤包层组成的复合系统。相关公认实践包括热塑性涵管设计和基础设计。 1.2 本规程规范了埋地热塑性结构制造商使用土壤支撑作为结构系统的组成部分来设计塑料随时间变化的行为的方法。本规程不适用于不包括土壤支撑作为结构系统组成部分的热塑性结构。 1.3 本规程仅限于结构设计，不提供雨水收集室功能使用可能需要解决的水力、水文或环境设计考虑方面的指导。 1.4 雨水室通常嵌入露天级配、角状骨料中，为蓄水提供结构支撑和露天孔隙。如果规定埋置的土壤不是露天级配、角骨料，则可能需要解决本实践范围以外的其他安装和功能问题。 1.5 腔室以拱形生产，以满足指定腔室高度、腔室跨度、最小英尺宽度、最小壁厚和最小拱刚度常数的分类。 腔室采用整体式基脚制造。 1.6 聚丙烯腔室分类见规范 F2418 . 规格 F2418 还规定了腔室制造和鉴定。 1.7 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。 1.8 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。 1.9 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。 ====意义和用途====== 4.1 本实践为热塑性雨水室的结构设计提供了一种合理的方法。载荷、容量和极限状态基于热塑性塑料管道的可接受载荷和阻力系数设计；然而，由于以下原因，热塑性塑料管的现有设计规范没有充分解决腔室的设计问题: (1) 打开底部几何体， (2) 整体支脚支撑， (3) 变化的周向波纹几何形状，以及 (4) 使用替代热塑性树脂制造。本实践规范了设计师的建议，以充分解决腔室设计的这些方面。 4.2 本规程旨在使腔室制造商能够评估满足现有分类的腔室，并在开发新分类时设计腔室。

1.1 This practice standardizes structural design of thermoplastic corrugated wall arch-shaped chambers used for collection, detention, and retention of stormwater runoff. The practice is for chambers installed in a trench or bed and subjected to earth and live loads. Structural design includes the composite system made up of the chamber arch, the chamber foot, and the soil envelope. Relevant recognized practices include design of thermoplastic culvert pipes and design of foundations. 1.2 This practice standardizes methods for manufacturers of buried thermoplastic structures to design for the time dependent behavior of plastics using soil support as an integral part of the structural system. This practice is not applicable to thermoplastic structures that do not include soil support as a component of the structural system. 1.3 This practice is limited to structural design and does not provide guidance on hydraulic, hydrologic, or environmental design considerations that may need to be addressed for functional use of stormwater collection chambers. 1.4 Stormwater chambers are most commonly embedded in open graded, angular aggregate which provide both structural support and open porosity for water storage. Should soils other than open graded, angular aggregate be specified for embedment, other installation and functional concerns may need to be addressed that are outside the scope of this practice. 1.5 Chambers are produced in arch shapes to meet classifications that specify chamber rise, chamber span, minimum foot width, minimum wall thickness, and minimum arch stiffness constant. Chambers are manufactured with integral footings. 1.6 Polypropylene chamber classifications are found in Specification F2418 . Specification F2418 also specifies chamber manufacture and qualification. 1.7 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. 1.8 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. 1.9 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. ====== Significance And Use ====== 4.1 This practice provides a rational method for structural design of thermoplastic stormwater chambers. The loads, capacities, and limit states are based on accepted load and resistance factor design for thermoplastic pipes; however, existing design specifications for thermoplastic pipes do not adequately address the design of chambers due to (1) open-bottom geometry, (2) support on integral foot, (3) varying circumferential corrugation geometry, and (4) manufacture with alternative thermoplastic resin. This practice standardizes recommendations for designers to adequately address these aspects of chamber design. 4.2 This practice is written to allow chamber manufacturers to evaluate chambers meeting existing classifications and to design chambers for new classifications as they are developed.