Evaluation on Ground Suitability of Shield Tunneling Based on Rock Engineering System

For the widespread complex strata in China, there always exits kinds of construction problems because of the unsuitability of shield with regard to different ground types. However, it has been very difficult to evaluate the degree of suitability for the complexity of interaction between shield machine and ground. In this research, a systemapproach based on rock engineering system(RES) is applied to this issue for the first time and a Shield-Ground Suitability Index (SGSI) is defined for evaluating tunneling performance of shields and corresponding ground responses. According to the primary difficulties of EPB shield tunneling in complex ground, seven critical factors including thrust force, torsional moment, advance rate, energy consumption, cutter wear, ground loss and surface settlement were taken into account for the SGSI definition. After rating the influencing parameters and coding the interaction matrix, influence weights of system's parameters and the aimed SGSI can be determined by the interaction matrix. Then a clear correlation between the grading of SGSI and performance of EPB shield tunneling has been revealed. In the end, a case study is illustrated to demonstrate the application of this proposed model.