Influence analysis of the key parameters in the expansion construction of existing mountain tunnels
In order to provide scientific guidance for the design and construction of the expan-sion of existing tunnels,a three-dimensional numerical model was established based on an existing mountain tunnel reconstruction and expansion project.The accuracy of the calcula-tion model was verified by comparing it with the monitoring data,and then the construction plan was analyzed and optimized based on the numerical model.The results show that con-sidering the construction progress and safety on site,the cycle footage is recommended to be 2.0 m.The length of the bolts is negatively correlated with the deformation of the surround-ing rock,and the longitudinal spacing of the bolts is positively correlated with the deforma-tion of the surrounding rock.When the longitudinal spacing of the bolts exceeds 1.0 m,the deformation of the surrounding rock increases significantly.It is therefore recommended that anchor rods with a length of 3.0 m and a longitudinal spacing of 1.0 m should be used for support.The research conclusions can provide reference and basis for similar projects.
NETL
NSTL
万方数据
维普
