The principal objective in compiling the material for this CONCRETE PIPE DESIGN MANUAL was to present data and information on the design of concrete pipe systems in a readily usable form. The Design Manual is a companion volume to the CONCRETE PIPE HANDBOOK which provides an up-to-date compilation of the concepts and theories which form the basis for the design and installation of precast concrete pipe sewers and culverts and explanations for the charts, tables and design procedures summarized in the Design Manual.
Special recognition is acknowledged for the contribution of the staff of the American Concrete Pipe Association and the technical review and assistance of the engineers of the member companies of the Association in preparing this Design Manual. Also acknowledged is the development work of the American Association of State Highway and Transportation Officials, American Society of Civil Engineers, U. S. Army Corps of Engineers, U. S. Federal Highway Administration, Bureau of Reclamation, Iowa State University, Natural Resources Conservation Service, Water Environment Federation, and many others. Credit for much of the data in this Manual goes to the engineers of these organizations and agencies. Every effort has been made to assure accuracy, and technical data are considered reliable, but no guarantee is made or liability assumed.
The design and construction of sewers and culverts are among the most important areas of public works engineering and, like all engineering projects, they involve various stages of development. The information presented in this manual does not cover all phases of the project, and the engineer may need to consult additional references for the data required to complete preliminary surveys. This manual is a compilation of data on concrete pipe, and it was planned to provide all design information needed by the engineer when he begins to consider the type and shape of pipe to be used. All equations used in developing the figures and tables are shown along with limited supporting theory. A condensed bibliography of literature references is included to assist the engineer who wishes to further study the development of these equations.
Chapters have been arranged so the descriptive information can be easily followed into the tables and figures containing data which enable the engineer to select the required type and size concrete pipe without the lengthy computations previously required. All of these design aids are presently published in engineering textbooks or represent the computer analysis of involved equations. Supplemental data and information are included to assist in completing this important phase of the project, and illustrative example problems are presented in Chapters 2 through 4. A review of these examples will indicate the relative ease with which this manual can be used.
The revised Chapter 4 on Loads and Supporting Strengths incorporates the Standard Installations for concrete pipe bedding and design. The standard Installations are compatible with today’s methods of installation and incorporate the latest research on concrete pipe. In 1996 the B, C, and D beddings, researched by Anson Marston and Merlin Spangler, were replaced in the AASHTO Bridge Specifications by the Standard Installations. A description of the B, C, and D beddings along with the appropriate design procedures are included in Appendix B of this manual to facilitate designs still using these beddings.
HYDRAULICS OF SEWERS
The hydraulic design procedure for sewers requires:
- Determination of Sewer System Type
- Determination of Design Flow
- Selection of Pipe Size
- Determination of Flow Velocity
DETERMINATION OF SEWER SYSTEM TYPE
Sanitary sewers are designed to carry domestic, commercial and industrial sewage with consideration given to possible infiltration of ground water. All types of flow are designed on the basis of having the flow characteristics of water.
DETERMINATION OF DESIGN FLOW
In designing sanitary sewers, average, peak and minimum flows are considered. Average flow