A multi-coupling analysis of mining-induced pressure characteristics of shallow-depth coal face in Shendong mining area

For shallow-depth mining-induced pressure characteristics of Shendong mines, combining with 126 cases of shallow buried coal face pressure measurement data, the regression analysis and probability statistics analysis were conducted regarding the single and coupling influences on the maximum mining-induced pressure, pressure distribution and pressure step caused by overlying strata lithology, mining height, buried depth and face length.At the same time, KSPB software and overburden rock hardness coefficient method were used to quantify the strata lithology.The results show that (1) Under the condition of no, single and multiple key stratums, the strata lithology, mining height, buried depth and face length have the relationship of linear, linear, negative logarithm and double logarithmic function with maximum mining-induced pressure, and different strata lithology conditions have different parameters; (2) Pressure distribution has the characteristics of the quadratic function on face length direction.When face length increases, the pressure distribution parameter -a decreases with the form of negative logarithmic function, different strata lithology conditions have different parameters, and strata lithology, mining height and buried depth have little influence on pressure distribution; (3) Under different strata lithology situations, in working face, first and periodic pressure step have the relationship of exponential function with strata hardness coefficient, and mining height, buried depth and length of working face are related to probability distribution, and the union values of strata hardness coefficient of expected value and probability statistics value are the face first and periodic pressure step.Comparative analysis and engineering practice show that experience regression formula combining with probability statistics, within a certain residual, can accurately estimate the shallow buried coal face maximum pressure, pressure distribution and the pressure step of coal face, providing a reference for the selection of hydraulic support and the control of face roof in similar geological conditions.