Study Of Bolting Support Technology For Mining Gateway With Thick Mudstone Roof In Xinqiao Coal Mine

The common way of coal mining is underground mining in China, and roadway surrounding rock conditions are varied and irregular. In recent years, with the rapid development of coal mining, its scale becomes larger and larger, but the problems of supporting the mining gateway with thick mudstone roof are increasingly obvious.Combining roadway surrounding rock conditions of No.2107track trough of Xinqiao Mine, analyzing the drilling peep result of roof rock crushing, and testing mineral composition and rock mechanics parameter of rock samples in the laboratory, based on these, this paper uses a variety of analytical methods, such as theoretical analysis, numerical simulation, in-situ observations and so on, to study on supporting parameter of bolt and cable and on the deformation of thick mudstone rock anchoring by force. The paper mainly contains:①through field investigation, geological data and borehole analysis, reveal mainly the characteristics of thick mudstone roof condition: the roof within the scope of the bolt (cable) anchoring cannot lean to hard rocks which can be the anchorage bearing layer, easily broken and low-intensity;②testing surrounding rock composition and rock mechanics parameters of thick mudstone roof: uniaxial compressive strength of the sampling rock is less than7MPa, low strength of rock, poor structural integrity of rock, joint development and rock mechanics properties and larger difference is easy to soften in the water leaching and weathering conditions, roof rock in the absence of mine pressure also can appear the fissure, fall block, crushing and other phenomena its bearing capacity greatly weaken in the common effect of water and wind;③the intrinsic instability reason analysis since the2107track trough was deformed by force resulted from combining numerical simulation and monitoring information;④the major revealed factor of roadway supporting, the summarized roadway supporting principle of thick mudstone roof, and the active supporting scheme which is put forward, which are got by combining with numerical simulation and theoretical analysis, namely: bolt+M steel strip+cable+net+steel beam of the active supporting scheme under the condition of thick mudstone roof;⑤verification and evaluation of supporting effects through numerical simulation and field experiment, the effects show that the speed of deformation of roof rock slows down, that the average speed is2mm/d, that60days later, roof deformation tended to be stable, the deformation is about120mm, supporting that surrounding rock has a loose circle from2m to3.5m, and that the structure is stable. The targeted support scheme has obvious effect on controlling the stability of roadway surrounding rock.The results of this study will provide theoretical and technical reference value for the future to deal with the problem of the tunnel support, which is of great significance to ensure rapid heading and safe production of2107track trough.