Abstract:

The mechanical behavior and deformation of the frozen soil umbrella in shield junction under artificial freezing condition in Qiongzhou strait tunnel are studied by using threedimensional finite element numerical simulation method. The simulation is conducted in different ways in order to make evaluations on two different freezing methods, i.e., singlerowpipe freezing method and doublerowpipe freezing method. Great emphasis is put on the demolition of cutter head in shield junction. In the simulation, cutter head of different lengths in the circumferential direction is demolished, which would definitely affect the mechanical behavior and deformation of the frozen soil umbrella. The research demonstrates that the doublerowpipe freezing method is superior to the singlerowpipe freezing method in terms of safety. The length of cutter head demolished has great influence on the mechanical behavior and deformation of the frozen soil umbrella. The paper can provide reference for shield junction under soil freezing condition. 

Key words: Qiongzhou strait, submarine tunnel, ground reinforcement, freezing method, shield junction, frozen soil umbrella, mechanical analysis, numerical simulation