Study on the influence mechanism of excavation unloading scheme on the structure of existing metro tunnel
With the continuous advancement of urban construction,underground engineering has entered a period of rapid development,and the influence of foundation pit engineering on the existing structure below cannot be ignored.Based on this,this article takes the excavation of the foundation pit above a metro transfer station project as an example,and analyzes the deformation state of the tunnel roof structure above the existing tunnel structure under the conditions of one-time excavation,partition excavation,and skip excavation by using FLAC3D numerical simulation software.The analysis results show that the order of the maximum vertical deformation of the roof structure under the three working conditions is as follows:One-off excavation condition＞zoned excavation condition＞skip excavation condition.Compared with one-off excavation scheme and zoned excavation scheme,the skip excavation scheme could reduce the maximum displacement of the tunnel roof by 48.6%and 38.3%respectively,which could effectively reduce the excavation deformation of the foundation pit.The relevant research could provide a reference and example to build on for the construction project of this kind of engineering.
existing metrounderpass tunnelexcavation schemenumerical analysismechanism study
NETL
NSTL
万方数据
维普
