Study On The Interaction Between Soft-Weak Surrounding Rock And Initial Support Of Deep Buried Tunnels

The interaction between soft-weak Surrounding Rock and initial support of deep buried tunnels has become one of the most important subjects in underground engineering research. The subject involves the deformation of surrounding rock, the reaction of support, coupled action of surrounding rock and initial support and so on. The increasing depth of tunnel makes the demands of stabilization of surrounding rock and optimization design of initial support especially for soft rock more and more seriously. The key of solving these problems is to make clear of the interaction between surrounding rock and initial support, which will increase the depth of tunnel and ensure the tunnel's safe employment. So the key needs further study and exploration. Contents and resulting achievement of this paper are as follow: (1) The geologic engineering characteristics and the mechanical attributions of deep buried soft rock were thoroughly unfolded in this paper. The deformation characteristics of soft-weak Surrounding Rock and its influence coefficient and supporting principle of soft-weak Surrounding Rock in deep buried tunnel were also elucidated. (2) On the basis of full analysising the methods and technologies of in situ minitoring for tunnel, the deformation characteristics of surrounding rock and initial support mechanical are analyzed according to monitoring data of Tong-yu deep buried tunnel. (3) On the basis of deformation trend of surrounding rock and stress trend of initial support gained through trend prediction by regression analysis and gray model according to monitoring data of Tong-yu tunnel, the stabilization of the tunnel is analyzed. (4) Using mechanisms of initial support, the deformation of surrounding rock, stress of initial support and interaction between surrounding rock and support are argued under different parameters of surrounding rock and support. And a project is analyzed, that provides right principles for design and construction of initial support. (5) It is presented that the specialties of FEM (Finite Element Method) used to simulate the excavation in underground engineering. In the simulation of Tong-yu tunnel, deformation of surrounding rock, stress of initial support and effect of support are studied under different rates of load releasing, parameters of bolt and construction methods, that provides the reference to design and construction for initial support.