摘要
Abstract
In order to reveal the evolution law of surrounding rock deformation in a tunnel with silty clay formation,a numerical calculation model of a highway tunnel was constructed by using finite difference numerical calculation software to study the evolution characteristics of surrounding rock deformation under different excavation methods.The results show that with the gradual increase of the number of tunnel excavation steps,the displacement evolution characteristics of the arch,arch and invert of the tunnel surrounding rock under the three excavation methods are similar,and the change law is mainly stepped.The upper and lower step method has great influence on the displacement and settlement of the tunnel arch,while the three-step and seven-step excavation method has obvious influence on the deformation of the surrounding rock at the tunnel arch and invert.When the excavation method of three steps and seven steps is adopted in the construction of tunnel in weak strata,the initial supporting measures of surrounding rock should be strengthened to ensure the closed-loop of supporting structure and prevent the large deformation of surrounding rock.关键词
黏土地层/公路隧道/围岩变形/有限差分Key words
Clay formation/Highway tunnel/Surrounding rock deformation/Finite difference分类
交通工程
