Method for calculating deformation pressure of surrounding rock of deep-buried tunnels

The pressure of surrounding rock is an important research content of tunnel engineering, and it includes deformation pressure. The study on the deformation pressure is of great significance to ensure the safety and economic construction of tunnels and underground engineering. The method of mathematical statistics is used to analyze the influence degrees and variation laws of grade of surrounding rock, tunnel span and tunnel depth on the deformation pressure through a large number of filed measured data. The formula for calculating the vertical deformation pressure is established by using the multivariate nonlinear regression analysis method. The deformation pressure is about 84%~92% times the value by the "Code for design of railway Tunnels" according to the analysis. As the grade of the surrounding rock increases, the ratio decreases continuously. The lateral pressure coefficient of deformation loads obeys the normal distribution. The lateral pressure coefficient of each surrounding rock condition has a certain increase compared with that in the "Code for design of railway tunnels". The research achievements have certain reference guidance for the design of tunnels and underground supporting structures in China.