Numerical Simulation Research On Ground Motion Caused By Coal Excavation In Several Landforms

The law of ground motion caused by coal excavation is different on different landforms. In this thesis, the coal excavation is simulated using FLAC3D. Taking Tanggongta Coal 1601 working face, Antaibao Coal 90102 working face and Anjialing Coal 4106 working face for examples, it comes to a conclusion of the influence on ground motion caused by coal excavation in three different landforms.(1) Steep slope has a huge effect on ground motion. Because the slope is steep, the position of the largest vertical displacement is facing the direction of fall and horizontal displacement is larger than it would be. Vertical displacement incidence and horizontal displacement on the slope are larger than on the valley.Besides, forty steps excavation is simulated and the laws of ground, layers above and under the coal motions are concluded. The ground begins to sink when 40m coal are excavated. The coal is fully excavated when 260m coal are excavated. Before the full excavation, the ground and layer above the coal sink every three steps. Layer under the coal rises during the excavation.(2) Gentle slope has few effects on ground motion. However, because the working face is located on the slope, the position of the largest vertical displacement is slightly facing the direction of fall. Vertical displacement incidence and horizontal displacement on each side of the working face are also different.(3) Ridge has few effects on ground motion. However, because the landforms on each side are not symmetry, the horizontal displacement is smaller in valley and larger on the slope.At last , ground motion caused by coal excavation in different landforms is compared, ground motion is influenced by slope tendency, obliquity and tiny landforms nearby.