This Standard covers the direct design of buried one-cell precast reinforced concrete box sections for the conveyance of sewage, industrial wastes, storm water and drainage, and to serve as tunnels. The design and analysis method accounts for the interaction between the box sections and soil envelope in calculating loads, pressure distributions, moment, thrust and shear in the box section, and includes a procedure for calculating the required reinforcement. Load effects are determined separately for each loading. The structural design of one-cell precast reinforced concrete box sections is based on a limits state design procedure that accounts for strength and serviceability criteria and is consistent with the procedures outlined in Section 17 of the AASHTO Standard Specification for Highway Bridges. The design criteria include: structural aspects, such as flexure, thrust, and shear strengths; handling and installation; fatigue limits; and crack width control.

The design of a one-cell precast reinforced concrete box section is based on the assumption that specified design bedding and installation requirements will be achieved during construction of the installation. Owners and owners engineers will find this Standard useful in preparing contract documents based on the direct design method.