Standard Practice for Direct Design of Precast Concrete Box Sections for Jacking in Trenchless Construction

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.