Evaluation of Structural Performance and Optimizing Design for Lattice Girders Reinforced Shotcrete
Lattice girders have been widely used as a temporary support or part of the permanent lining for NATM tunneling. In order to evaluate the structural performance of lattice girders reinforced shotcrete, influential factors such as diameter of main steel bar and diagonal bar, welding length, stirrup were studied. Moreover, interaction between rock and lattice girders reinforced shotcrete was also taken into consideration. Then, lattice girders reinforced shotcrete structure was optimized. A new experimental system which could simply simulate rock mass and structure interaction was proposed. A series of unit models were designed to investigate ultimate loading capacity and local failure performance of lattice girders reinforced shotcrete using experiment and numerical approaches. In the numerical study, a plastic–damage model was performed. Results revealed that simulated load-displacement curves and failure models were in good agreement with the experimental study.