本标准提供了预制混凝土箱形截面的最新设计和建议安装程序，用于非开挖施工中的顶进，用于输送污水、工业废物、雨水和排水，以及公用设施和通道。直接设计法在确定荷载和埋置箱形截面上的土压力分布以及顶升引起的纵向荷载时，考虑了箱形截面和土壤或灌浆包层之间的相互作用。荷载和压力分布用于计算墙/板中的周向力矩、推力和剪力，以确定所需的钢筋。 设计标准包括:结构方面，如周向弯曲、推力和剪切强度；裂缝宽度控制；顶升产生的纵向推力；以及搬运和安装。

This Standard provides the latest in design and recommended installation procedures for precast concrete box sections for jacking in trenchless construction intended for the conveyance of sewage, industrial wastes, storm water and drainage, and for utilities and access ways. The Direct Design Method accounts for the interaction between the box section and soil or grout envelope in determining loads and distribution of earth pressure on buried box sections in additions to longitudinal loads due to jacking. The loads and pressure distributions are used to calculate circumferential moment, thrust, and shear in the wall/slab to determine required reinforcement. The design criteria include: structural aspects, such as circumferential flexure, thrust, and shear strengths; crack width control; longitudinal thrust produced by jacking; and handling and installation.