Evaluation and Application of the Flexural Rigidity of a Reinforced Concrete Pipe

Abstract

Design of reinforced concrete pipes focuses on circumferential bending moment. Analytical or numerical methods can be used to estimate these, but an adequate representation of the soil conditions and pipe properties is necessary. The objective of this research study is to use simple experiments (three-edge bearing tests) along with closed-form solutions to obtain the circumferential flexural rigidity of a 600 mm reinforced concrete pipe for use in calculating moments from experimental measurements of changes in curvature (without knowledge of the soil and loading conditions). The data from the experiments were also used to calculate an elastic modulus that can be used to represent the circumferential flexural rigidity of the specimen in numerical simulations without having to model the reinforcement. An assessment of the methods used in this research study is also presented. Finally, use of the circumferential flexural rigidity in interpretation of buried pipe experiments is illustrated where moments in a reinforced concrete pipeline subjected to live loading are inferred from measured strains, comparing pipes for different burial depths and configurations.