Slope Stability Analysis In Hongshaquan Open-pit Coal Mine

The research objects of this paper are the stope slope of Hongshaquan open pit coal mine.Combine the natural climate condition of the mining area and investigated the adverse geologic phenomena.Determine the adverse factors affecting slope stability of mine is weak layer.The weak layer weakened when encountering water and strength decrease.The slope is prone to landslides along the weak layer.Evaluate the causes and safety of the bad engineering geological phenomena by actual situation of the slope.Get the physical mechanical indicators of the rock samples by physical mechanical experiments.Estimate strength of rock mass by Hoek-Brown strength criterion.Combined with the back analysis of parameters in slide zone of in-pit dump,the recommended physical mechanical parameters of rock mass are obtained.Using numerical analysis software based on the FLAC finite difference method.Analyze the failure mechanism of west end slope,in-pit dump and non working slope.Obtain the slope failure forms and some potential damage sites.Analyze the stability of the slope by ultimate balance theory.Calculate the safety factor of slope.As known from the calculation,the potential failure mode of the stope is consequent landslide.Status and design safety coefficient is greater than 1.3,satisfied the reserve requirements of slope safety.The slope is stable and the risk of the landslide is low.The potential failure mode of the in-pit dump is comprehensive failure.Status safety coefficient is 1.07~1.16 and less than 1.15 in some area.Local landslides may occur.Safety coefficient of annual design slope is less than 1.0,landslides probably occur according to the original design.Optimize the bench height of the in-pit dump,bench height is 20 m above +580m flat and step height is adjust from 20 m to 15 m below +580m.Dump until the end of the line.