Theoretical And Experimental Analysis And Design Application On Surrounding Rock Resistant Coefficient For Large-span Undersea Tunnel

Xia'men east passage Xiang'an undersea tunnel is the first being constructed urban domestic undersea road tunnel. Without special undersea tunnel design code, the design of Xiang'an tunnel support system and lining has to refer the code for design of road tunnel, which is present tunnel design code.The rock elastic resistant coefficient is a basic and key parameter to determine the surrounding rock resistant force, and its value could only be obtained by referring to the code or by designer's personal experience.As to the long-span-flat-arch undersea tunnel in Xia'men city, theoretical research work and indoor experiments must be carried out because of the lack of practical undersea tunnel design experience. The research achievements have not only theoretical and academic meaning, also engineering application use.As we all know, the accurate analytic solution of the rock resistant coefficient can be obtained under the condition of circle profile and bearing uniform compress force in the inner tunnel boundary by use of the local deformation theory, and solutions of any other conditions are only approximate ones.In the dissertation, the derivative process is under the ideal condition of circle profile and bearing uniform compress force in the inner tunnel boundary to get the analytic expression of rock resistant coefficient.The main works and research achievements of this dissertation are as follows.(1)By systematizing the research achievements in the field of rock resistant coefficient, six calculation methods on the basis of different constitutive models or practical engineering cases are obtained.Research results show that rock resistant coefficient is a overall factor, and it is closely related to loads condition, tunnel geometry size and geotechnical parameters, etc. The results can also be applied to the elastic-plastic deformation state surrounding rock and the silt-rich rock mass.(2) The most obvious difference between the Unified Strength Theory and others strength theories lies in the fact that the former induce a material yield factor to reflect the intermediate principal stress effect, while others strength theories only...