Hybrid Gauss Points Integration Method for Explicit Dynamic FEM Analysis of Hydropower Underground Caverns

The anti-seismic analysis of large-scale underground caverns is always a difficult issue. When explicit dynamic finite element method(FEM) is adopted to perform time history analysis towards large-scale underground caverns, the consuming time is considerable and thus lowers the efficiency of project analyzes. To enhance the solving speed of explicit dynamic FEM, the hybrid method is presented based on using different integration strategies in terms of single gauss point integration method and multi gauss points integration method. Therefore, fast speed of single gauss integration as well as high precision of 8 gauss points integration are both realized by. An example is given on the dynamic time history analysis of surrounding rock of underground caverns in a hydropower plant. The results show that the computation efficiency is improved by 82.4%. It proves the effectiveness of the proposed method.