FEM application to loess slope excavation and support: case study of Dong Loutian coal bunker, Shuozhou, China

The largest coal bunker in China will be built in the Dong Loutian loess region to store coal, and the long V-shaped loess slope of the bunker, more than 60 m in depth, will be excavated. The finite element method of numerical simulation is applied (using linear elastic and hardening soil models) to simulate stability of the excavation slope and deformation with and without reinforcement, with a view to predict the deformation trend, design the reinforcement scheme, decrease the unrealistically large heave at the base of excavation and horizontal displacement of the excavation slope, and ensure the safety of the project. The simulation results show that the stress field redistributes after excavation and reinforcement, and the horizontal displacement of the slope is inhibited effectively, while the soil at the base of the bunker should be emphatically compacted and supported by piles. The field-measured data are in better agreement with the results calculated from the hardening-soil model and the combined support mode of anchor and soil nail. Thus, the results can be used to determine the key deformation range and reinforcing areas for engineering design.