Application Of FINAL Program To Underground Projects

FINAL program is a famous FEM analysis software, which is widely used in underground projects. FINAL can effectively simulate various rock materials and joints or faults. The program can also simulate the rock excavation and support process. The author applied FINAL program to tunnel and underground caverns, and analyzed the structure and the effect of the reinforcement methods. This thesis focuses on the following aspects:1. FINAL program and its simulation methods on the excavation and reinforcement of underground projects were introduced. Using the BEAM6 and BOLT element, the behavior of the shotcrete and the grouted bolts can easily be simulated. Using the above methods and elements, an example of tunneling was calculated. 2. Using FINAL, the structure analysis of the Guangzhou subway Line 4# tunnel in Huangzhou section was carried out. The process of excavation with the New Austrian Tunneling Method was exactly simulated. The subsidence of the ground surface is obtained. And its influence on nearby buildings was analyzed. 3. This thesis also simulated the excavation process of the underground plant of Shuibuya project with FINAL program. The simulation of the complex geological condition and different reinforcement methods were involved. The distribution of displacement, stress state and plastic areas were studied. Based on those, the stability of the surrounding rock mass and the effect of reinforcement is analyzed. Another part of work of this thesis focuses on the integration algorithms for perfect plasticity based on Drucker-Prager criterion. It is revealed in this thesis that the analytic solution for transferred stress mentioned in this thesis is equivalent to the so-called closest point projection algorithm, so the solution is of first-order accuracy and unconditional stable. A subincrementing scheme is proposed to combine with the analytic solution. Both theoretic analysis and numerical example show that the analytic solution for transferred stress are suitable to limit analysis and achieve high accuracy to large strain increment even without subincrementing scheme.