Abstract
The formation mechanism of surrounding rock pressure in large-section tunnels of underground excavation is still unclear. The traditional methods for calculating surrounding rock pressure have certain limitations. Based on the theory of pressure arch and parameter sensitivity analysis, the internal and external boundaries of the pressure arch are solved by numerical simulation. The loose pressure is obtained according to the distance from the inner boundary to the inner wall of the tunnel. The pressure arch deformation is analyzed based on the Winkler model. The surrounding rock pressure is calculated, and the surrounding rock pressure based on the pressure arch theory is calculated. The calculation method of surrounding rock pressure based on the pressure arch theory large section tunnel is proposed. The orthogonal experimental design method was used to select four representative factors: tunnel depth H, span B, internal friction angle φ and rock weight γ. The calculation results of each group of experiments were compiled and multivariate linear regression was used. The method is statistically analyzed, and finally, the calculation formula of the surrounding rock pressure of the large-section tunnel affected by multiple factors is obtained and applied to the calculation of the surrounding rock pressure of the metro station.
Highlights
Shang et al DOIBased on the principle of stress transfer and soil pressure, Terzaghi theory calculates the overall stress situation of the rock mass in the upper sliding zone of the tunnel by analyzing the stress balance of the differential soil stripes, and calculates the lateral pressure of the soil column during the slide by combining the lateral pressure coefficient and Mohr-Coulomb law
In practical application, when the surrounding rock pressure is calculated by Terzaghi theory and Bill Bowman theory, negative values may occur due to the large cohesion of the rock mass, which is inconsistent with the actual situation
For the calculation of surrounding rock pressure under the influence of multiple physical parameters of tunnel surrounding rock, the orthogonal experimental design can be used to carry out the research, and the influence degree of each physical parameter on the calculated value can be analyzed, and the calculation method of surrounding rock pressure based on the pressure arch theory can be simplified into a practical calculation formula
Summary
Based on the principle of stress transfer and soil pressure, Terzaghi theory calculates the overall stress situation of the rock mass in the upper sliding zone of the tunnel by analyzing the stress balance of the differential soil stripes, and calculates the lateral pressure of the soil column during the slide by combining the lateral pressure coefficient and Mohr-Coulomb law. Θ angle and calculated friction Angle can only be evaluated according to a certain range given by the code, which are difficult to obtain in engineering practice This makes Xie Jiaxiao theory have some limitations when applied to the surrounding rock pressure of tunnel engineering solution. Jianhong Wu et al [10] conducted mechanical behavior simulation of cutters rock mass with DDA numerical method, and qualitatively analyzed the arch shape and development process of surrounding rock pressure with the change of element stress direction as the judgment index. Martino et al [14] studied the pressure arch from different angles by using finite element or discrete element
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
