Analysis of the Origin of Water Inrush Cofficient and Its Applicability

On the basis of its origin,the paper indicates that the water inrush coefficient is the reciprocal of the relatively impermeable layer thickness,discusses the reason why Chinese scholars take 0.06 MPa/m as its critical value,summarizes its evolution,and reveals its applicability of a variety of formulas.In addition,studies show that when the mining depth is less than 300 m,the failure depth caused by the underground pressure on the floor may not be consi-dered in the calculation of the water inrush coefficient,while it should be considered under the conditions of great mining depth.