Reliability-based design of rigid pipes installed by induced trench method with tire-derived aggregate inclusions

A reliability-based design (RBD) method for rigid pipes installed using induced trench with tire-derived aggregates (TDA) inclusion is introduced in this study. The design process is to find an optimal set of the TDA inclusion dimension (i.e., width B and thickness t) that satisfies the 0.01-inch crack serviceability limit state and ultimate failure limit state requirements of the pipe, and achieves a target probability of failure or target reliability index using Monte Carlo simulation. The uncertainty and load-dependent compressibility of TDA inclusion are considered. Two design examples are provided, which show that the serviceability limit state design controls the finial design of induced trench installation (ITI) pipes. Increasing the thickness of TDA inclusion is helpful to improve reliability of the pipes, while expanding the width of TDA inclusion might increase probability of failure. The sensitivity and flexibility of using different target reliabilities, parameter uncertainties and calculation models in the proposed RBD method are examined. The results show the importance of considering the variability and load-dependent compressibility of TDA in the proposed RBD method for the design of ITI pipes with TDA inclusions.