摘要
Abstract
Taking the in-situ reconstruction of super-large section tunnel at Jinji Mountain as the background,for the expanding excavation schemes based on traditional center diaphragm method or core five-step method respectively,elaborate numerical simulation was carried out,with the emphasis laid on how the pressure of surrounding rock,the bending moment of support,and the convergence of tunnel trunk change with the construction.The scheme based on core five-step method,from the viewpoint of construction efficiency,due to its simplified excavation zone,has the reduced 124 steps for construction from 144 steps in traditional center diaphragm method;from the pressure of surrounding rock and the bending moment of initial support,the unsymmetrical pressure of the rock in this scheme was relieved significantly,and the distribution of initial support's bending moment was more even with small absolute value of positive and negative bending moment;from the convergence of tunnel trunk,the both schemes has little difference.Above all,it is advised to use the scheme based on core five-step method for the reconstruction of super-large section tunnel at Jinji Mountain.关键词
特大断面隧道/原位扩建/扩挖方案/传统中隔壁法/核心五步法Key words
super-large section tunnel/in-situ reconstruction/expanding excavation scheme/traditional center diaphragm method/core five-step method分类
交通工程
