Analysis of the Sensitivity of Influencing Factors on Tunnel Secondary Lining Structure Stress

Abstract

On the basis of the load-structure model and FEM and taking the secondary lining of the Qingdao-Rongcheng intercity railway tunnel as a research object, sensitivity analysis of the influencing factors on the secondary linings internal forces is conducted via the sensitivity coefficient method. The influencing factors are the elastic resistance coefficient of surrounding rock, the secondary lining thickness, the elastic modulus of secondary lining, and the lateral pressure coefficient, whose values are taken from engineering practice. The analysis result shows that (1) to crown bending moment, the descending order of the sensitivities of the influencing factors are secondary lining thickness, elastic resistance coefficient of surrounding rock, lateral pressure coefficient, and elastic modulus of secondary lining; (2) to crown axial force, the descending order is lateral pressure coefficient, elastic resistance coefficient of surrounding rock, secondary lining thickness, and elastic modulus of secondary lining; (3) to crown vertical displacement, the descending order is elastic resistance coefficient of surrounding rock, secondary lining thickness, lateral pressure coefficient, and elastic modulus of secondary lining; and (4) for the safety factor of the crown cross section, the descending order is elastic resistance coefficient of surrounding rock, lateral pressure coefficient, secondary lining thickness, and elastic modulus of secondary lining.