| Due to the influence of interlayer fault on the development of the structure,the slab-rent structure rock has obvious structure and its deformation and failure characteristics are more complex.Especially in the deep,high ground stress and brittle rock tunnels,it will produce sudden rupture and even lead to rockburst,and it is dangerous to workers.Through the laboratory test,this paper studies the process of slab-rent structure tunnel surrounding rock rupture and water inrush and its influencing factors based on the similarity theory.Combined with the analysis of the stability of the stabilization of compressive bar of the material mechanics,fracture mechanism of slab-rent structure rock is analyzed.The following research results are obtained:(1)In brittle rhyolite rock test prototype,according to the mechanical and deformation characteristics of brittle rock mass,based on previous similar materials,by changing the ratio of gypsum,cement,sand and water to get the similar material of the model to meet the physical and mechanical properties of the test rock;(2)According to the purpose of the model test,the model framework,loading and plane strain restraint system are developed independently.Based on the characteristics of the slab-rent structure tunnel surrounding rock and the mechanical properties of rock,the model of the straight wall_slab cracking tunnel are designed.And the deformation characteristics and failure modes of surrounding rock under biaxial loading and void water pressure are studied;(3)The physical model test is used to study the tunnel model of 10mm,20mm and 30mm,the deformation characteristics of the tunnel with different thickness and the failure process of cracked wall rock under biaxial loading are revealed.Through the comparative analysis,the stress distribution law of tunnel surrounding rock is obtained;(4)According to void water pressure failure test of the tunnel with the thickness of 30mm,the failure and water inrush characteristics of the slab-rent structure tunnel surrounding rock under the action of pore water pressure are analyzed.Compared with the tunnel test specimens with the same thickness under biaxial loading,the failure process and stress distribution of the slab-rent structure tunnel surrounding rock under two loading conditions are analyzed;(5)Based on the assumption of ideal elasticity,the buckling mechanism of cracked rock mass is analyzed by using the principle of stabilization of compressive bar of material mechanics,and the greater the elastic modulus of the surrounding rock,the greater the thickness of the slab,the smaller the plate height,the greater the axial critical compressive stress.And verifies the correctness of the theory with the 1#test results,and analyzes the reason of the difference between the 2~#and 3~#. |
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