Research On Segment Mechanics Characteristic And Face Stability Of Tunnelling In The Process Of Shiziyang Tunnel Construction

The shield driving method,as one of the main construction methods of tunneling,has been used widely in China.The formation displacement and segment structure strees induced by construction is the main issue during shield tunnel construction and design.Taking Shiziyang underwater railway shield tunnul in the New Guangzhou-Shenzen-Hong Kong paseenger dedicated line as background,the paper includes: forces testing on segment and bolt,comparative analysis of four segment design methods and face stability of tunneling in slurry shield:(1) Force testing on segment and bolt of shield tunnel was completed by fiber grating sensor for the first time,obtain law and offer some reference for theoretical perfection.The fiber grating sensor,as a superior test method,may become leading sensor in civil engineering.(2) It is analyzed that the key steps during the construction with shield driving method;the main reasons for soil displacement;and the advantages and disadvantages of the existed FEM simulation methods for shield construction.The shortages of the existed method modeling the load of shield construction were covered and the 3D FDM model was established so as to simulate the shield construction process more reasonably and completely.(3) On the problem of the stability of excavation face in slurry shield tunnel,slurry shield tunnel were studied from the two aspects of a theoretical and numerical calculation.and the determine method of the stabilization of excavated surface on the soil loss theory is summede up successfully.With the use of FLAC3D calculation software in establishing the three-dimensional numerical model the frontage of shield excavation face and the law of ground settlement under different slurry pressure is investigated.