Study on the Calculation of the Surrounding Rock Stress on Shield Tunnels in Rock Strata

Due to the differences in techniques between the shield method and the mining method, it is not appropriate to directly draw from the relevant research results and experience of the mining method to calculate the surrounding rock pressure on shield tunnels. And the whole-soil column theory and the Terzaghi theory are only applicable to soft soil strata. Therefore, based on the theory of elasticity and construction characteristics of the shield method, this study has explored the surrounding rock pressure on the shield segment structure in rock strata. Based on the NATM and the ADECO-RS, the impact of the synchronous grouting layer, and the thick-walled cylinder theory, we have established the relationship among the surrounding rock, the synchronous grouting layer, and the segment and obtained the formula to calculate the surrounding rock pressure acting on the shield segment structure in rock strata. Additionally, we took the shield tunnels with moderately weathered and lightly weathered mixed granite on a road tunnel as the research targets and adopted the analytical method to calculate the surrounding rock pressure, which is 0.276yH and 0.192yH, respectively.