Influencing Factors And Stability Analysis On Continuous Accumulation Of Weathered Coal Gangue Dump

As the main wastes during the exploitation of coal mine, the quantity of coal mining wastes is increasing. So far as I know, only a small number of wastes can be recycled, the rest are accumulated into the coal gangue dump that abandoned in the mountain area or ravine region. The coal mining wastes has caused many problems, such as the pollution of environment. At some time, the coal gangue dump may bring about severe geological disasters such as landslide, debris flow that can be a threat to people’s life and property. This paper is based on the typical characteristic of coal gangue dump in Chongqing. First of all, make a survey of the coal gangue dump. Then, the shear resistance parameters of coal mining wastes will be obtained by comparison of strength characteristics test. Furthermore, Comparing with the safety factors that obtained in FLAC3 D, study on the stability of slope that based on the coal gangue dump which has a bi-level slope in FLAC3 D. To achieve the purpose of research, this paper has done some work from the following aspects:(1) Field survey of coal mining wastes can make a summary of typical accumulated state of coal gangue dump. Based on the coal gangue dump that accumulated against the mountain, analyze the gradation composition of coal mining wastes which accumulated long time ago and that accumulate recently. Test the moisture content of different materials in the conditions include natural state and saturated state. Analyze the chemical composition of weathered coal mining wastes. Analyze the content of organic carbon by ignition test.(2) The field test can obtain shear strength parameters which belonged to weathered coal mining wastes. Do the laboratory test by using new wastes and weathered wastes. Acquired the shear strength parameters of weathered wastes in different conditions which controlled by moisture content and gradation composition. Acquired the shear strength parameters of new wastes in condition that controlled by moisture content. At last, do the axial compression test to obtain the deformation characteristics that in different conditions of two materials.(3) Establish model of coal gangue dump according to the survey data and filed survey in FLAC3 D. To begin with, analyze the self-stability of weathered coal gangue dump with different slope angle. Obtain the safety factor in conditions that include natural state and saturated state. Analyze the elements that affect the stability of coal gangue slope. These elements may contain the angle of slope, the height of dump, the dump region and the depth of saturated zone.(4) Analyze the stability of weathered coal gangue slope by using FLAC3 D in the condition that new wastes can accumulate in different state. However, before the analysis, make sure that different dump can ensure their self-stability. Analyze the stability of weathered slope in the condition that new wastes can accumulate in different state, such as different angle, height and saturated depth of coal gangue slope.