DESIGN METHOD FOR REINFORCED CONCRETE PIPE AND BOX SECTIONS. REVISED EDITION
A design method based on consideration of strength and serviceability performance limits is proposed for concrete pipe box sections subject to known moments, shears and thrusts. Strength performance includes consideration of flexural strength as governed by reinforcement tension, concrete compression, concrete radial tension, and stirrup radial tension. Strength also includes consideration of diagonal tension strength in straight and curved members with and without stirrups. Serviceability performance includes consideration of crack control based on evaluation of a limiting crack width, selected by the designer. The limiting crack width is related to an average maximum crack width of 0.01 in. using a crack control index number. Design equations are presented for determining the required wall thickness, concrete strength, and reinforcement type and area for reinforced concrete pipe and box sections, based on the above criteria. When soil loads and their distribution are determined by existing methods, these new equations may be used for direct design of buried pipe and box sections. They may also be used for design of pipe to meet specified 3-edge bearing strengths, as currently employed in indirect designs of buried pipe. To facilitate such indirect design, specialized design equations for 3-edge bearing loads are also presented, based on the basic design equations and the moments, shears and thrusts caused by 3-edge bearing loads. Key relations proposed for reinforcement stress at 0.01 in. crack width and concrete shear stress at diagonal tension failure are compared to existing equations in codes and previously proposed relations for pipe and box sections. Comparisons are presented graphically by plots of the major variables in the above relations. Examples are given illustrating the use of the proposed design method for buried pipe, buried box sections and pipe in 3-edge bearing. Results for a range of design conditions are tabulated for comparative analysis. Finally, the range of applicability and expected benefits from the use of the design method are discussed in the light of the results of example designs and previous experience of the authors.
- Published December 1980/Revised December 1982.
Simpson Gumpertz and Heger, Incorporated1696 Massachusetts Avenue
Cambridge, MA United States 02138
- Heger, F J
- McGrath, T J
- Publication Date: 1982-12
- Features: Appendices; Figures; References; Tables;
- Pagination: v.p.
- TRT Terms: Box culverts; Cracking; Design methods; Equations; Flexural strength; Graphics; Pipe; Reinforced concrete culverts; Reinforced concrete pipe; Serviceability; Tensile strength; Underground structures; Width
- Uncontrolled Terms: Graphical analysis
- Subject Areas: Bridges and other structures; Design; Highways; I20: Design and Planning of Transport Infrastructure;
- Accession Number: 00621706
- Record Type: Publication
- Files: TRIS
- Created Date: Apr 30 1992 12:00AM