NUMERICAL SIMULATION AND ANALYSIS OF TUNNEL CONSTRUCTION PROCESS OF UNSYMMETRICAL TUNNEL IN SOFT ROCK

With construction of a large number of mountain tunnels，the deformation control of construction in the tunnel of biased soft surrounding rock and its stability have become the focus of attention of the tunnel engineering． Taking Liujiazhuang tunnel of Shanghai-Kunming passenger line． By using the finite element software of ABAQUS， the whole section method，the steps method and the CD method，the construction process of the section passing through coal seam was simulated to get the stress and strain law of surrounding rock and supporting structure under different construction methods． Through optimization of the different methods and monitoring data compared with the results of numerical simulation，it could be concluded that using forepole method of up and down steps is more economic and reasonable than the rest construction schemes，and some measures and advices of deformation control were given，which provided important reference and reference for similar projects．