矿业科学学报 (Apr 2021)
Control theory of uniform strength support in deep roadway
Abstract
In this paper, a large number of coal mine roadway failure cases are investigated, and 6 types and 15 typical failure forms are extracted.The mechanical characteristics and stress distribution of surrounding rock of typical roadway shapes such as circular and rectangular are analyzed.At present, the technology of high-strength prestressed bolt support, full space collaborative support and concrete filled steel tube support have shown certain advantages in deep surrounding rock control.Furthermore, based on the gradient failure mechanism of roadway surrounding rock and the uniform strength beam support model of rectangular roadway proposed by the author's team, the conceptual model of uniform strength support control theory for surrounding rock of deep roadway is put forward.According to the stress characteristics of roadway surrounding rock, the stress state of surrounding rock can be effectively adjusted by means of slotting and pressure relief, grouting, bolt (cable)support and passive support with concrete filled steel tube.The goal that the surrounding rock at different locations can reach the equivalent stress intensity state which is safe and matches the ground stress ratio can be achieved, and the ideal state that the stress distribution tends to be uniform and the plastic zone range of surrounding rock is similar can be obtained.The supporting strength of roadway with different buried depth and different section shape is calculated, and the calculation formula of support strength required by uniform strength is given.The stress changes of surrounding rock of circular and rectangular roadways before and after uniform strength support are simulated, and the stress field of surrounding rock can be significantly improved after uniform strength support is verified.Uniform strength support control model provide theoretical and practical guidance for surrounding rock control of deep roadway to a certain extent.
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