Study On Damage Mechanism Of Water-rich Soft Rock And Supporting Control Of Roadway

For the deep energy in the complex environment coupled with high geostress and groundwater, the physical and mechanical properties of the surrounding rocks of underground engineering roadways will change greatly in the process of exploiting and utilizing. In addition, the natural diagenetic composition is complex, and the damage caused by water to the surrounding rocks is more serious than the damage caused by the mechanical factors, so the traditional mechanical model is not suitable for the application of such problems. In this paper, the failure mechanism and long-term stability control of the rich-water soft rock roadway are studied in terms of theoretical and numerical simulations:(1) Based on the continuum damage mechanics, the damage effect of water to rock is defined as the weakening effect of rock mechanics parameters. The humidity-related damage variables D? are introduced by carrying out the uniaxial compression test of muddy siltstone, and the expression of the time-sensitive damage variable Dt of soft rock in humidity field is fitted .(2) Based on tangent method, the nonlinear failure criterion of equivalent M-C rock with cohesion and internal friction angle is established. Using the Flac3D Embedded Fish Language Coding program,realizing the dynamic change of cohesion and internal friction angle,introduce the equivalent M-C nonlinear failure criterion into the numerical simulation application.(3) Combining with the aging damage variable D, and the current rheological model of the composite element, non-linear desrtructive characteristics of modified improved Cvisc creep damage constitutive model.(4) Using the results of the above research are applied to the numerical simulation of the stability of surrounding rocks in the 16-07 transit soft rock roadway affected by the water-rich environment in Xiaotun coal mine. and the numerical simulation method is used in the design of bolt and anchor support scheme.