Quantitative model for residual bearing capacity of corroded reinforced concrete pipe based on failure mode

Abstract

Reinforced concrete pipes (RCPs) are widely used as jacking pipes in various infrastructures, such as sewers, tunnels, and pipe galleries. However, owing to the presence of harmful chemicals and microorganisms in the surrounding environment, the pipe gradually corrodes, thereby thinning the pipe wall and lowering the residual bearing capacity (RBC) of the structure. For the daily maintenance of the RCP, the RBC should be evaluated precisely to ascertain the service status of the pipe, and if necessary, timely rehabilitation can be performed to yield the optimal repair outcome and cost efficiency. In this study, quantitative models for RBCs of both intact and corroded RCPs are proposed; these models are based on the plastic collapse failure mode of rigid pipe. Additionally, the impact of uncoordinated deflection between concrete and reinforcement has also been characterised. A series of numerical simulations were developed on the basis of the finite element method (FEM) to evaluate the RBC of corroded RCPs, and the FEM results are consistent with those of the quantitative model. Finally, three-edge bearing (TEB) tests were conducted by incorporating both intact and corroded RCPs. The results of the TEB tests also revealed the reliability of the quantitative model.