Reliability Analysis of Hydraulic System of a Tunnel-Erecting Machine Based on Dynamic Fault Tree and Bayesian Network

Abstract

Prefabricated utility tunnels play an important role in modern urban infrastructure construction. However, prefabricated utility tunnel segments are heavy, and the hoisting conditions are complicated, resulting in increased requirements in terms of the reliability of the equipment used for the erection and paving of utility tunnels, especially the hydraulic system of tunnel-erecting machines. Therefore, in this study, we performed reliability analysis of the hydraulic system of a tunnel-erecting machine. First, the working principle of the tunnel-erecting machine and its hydraulic system is analyzed, and a Takagi-Sugeno (T-S) dynamic fault tree model is constructed using the T-S dynamic fault tree analysis method, which is further transformed into a Bayesian network (BN) model. Secondly, according to the failure probability of the root node, combined with the BN conditional probability table (CPT), the failure probability of the leaf nodes of the hydraulic system of the tunnel-erecting machine in each time period and task time is forwardly inferred. Then, through the quantitative analysis of the sensitivity parameters in the BN analysis method, the importance of the components in the system can be reflected. Finally, the posterior probability of failure of the root node of the hydraulic system is calculated through the reverse reasoning of the BN analysis method, and the sensitive components of the system are identified. The results show that the proposed method can determine the main factors affecting the hydraulic system of a tunnel-erecting machine and provide reference for the safe operation of such equipment, as well as system maintenance.