Grey-Correlation Analysis of Factors Influencing Xiamen Xiang'an Subsea Tunnel Surrounding Rock Displacement

Xiamen Xiang'an Subsea Tunnel is the first subsea tunnel in Chinese mainland which is independently designed by the domestic experts. The design service life is 100 years. Drilling and blasting method is employed for excavation. One of the most difficulties during the process of construction is how to cross the deep weathering slots successfully and safely. In this paper BEM software BMP 2000 was used to simulate the surrounding rock displacement of F1 deep weathering slot, and uniform design and grey-correlation analysis method was applied to analyze the correlation between surrounding rock displacement and the influencing factors. The results show that lateral pressure coefficient is the most sensitive factor to horizontal convergence of surrounding rock, followed by the tensile strength of surrounding rock; but to the vault crown settlement of surrounding rock, Poisson's ratio is the most sensitive factor, followed by the internal friction angle. The research achievement has been using in the design and construction of Xiang'an Subsea Tunnel, and good results have been achieved.