ABSTRACT
In view of the construction of large section highway tunnel reconstruction and expansion, the article takes the Shenzhen-Shantou west reconstruction and expansion project as the research object, and systematically expounds on the construction safety and early warning standard of large section highway tunnel reconstruction and expansion. In this paper, the mechanical parameters of grade IV and V surrounding rock of Shen-Shan-West tunnel are determined by a uniaxial compression test. The ultimate shear strain and ultimate principal tensile strain of grade IV and V surrounding rock are determined by the numerical analysis method. The finite element limit analysis method is adopted to determine the construction early-warning index of the reconstruction and expansion of the Shenzhen-Shantou west highway tunnel under the influence of the existing tunnel under the condition of different net distances by taking the plastic strain transfixion in the rock and soil as the criterion, which guides the subsequent construction and technical reference for similar projects.
