Construction Control Technology for Overpassing Existing Tunnels in Foundation Pit Works of Underground Connecting Passage
An underground connecting passage has a long parallel distance with the built metro section tunnel.The bottom of the passage is only 2.036 m-3.32 m away from the top of the section tunnel,and the depth of the foundation pit is 6.86 m-7.6 m,which can only be constructed by open-cut method.In order to study the possible impact of project implementation on existing works,the overall excavation process of underground connecting passage is simulated according to the construction sequence of 8 blocks and 16 steps through MIDAS finite element software,systematically analyzing the impact and variation law of project implementation on tunnel deformation stability.In line with the existing engineering experience and simulation results,the rationality of the implementation suggestion of"small block,fast excavation,early closure and frequent measurement"is verified,and the analysis rationality of metro tunnel is proved by the changes in displacement and internal force of adjacent existing works.Through post-construction evaluation and comparison,it is proved that the implementation suggestions have well controlled the impact of ultra-close range construction on existing works and controlled its impact within the allowable range.This paper puts forward relevant suggestions on the implementation of engineering projects under similar conditions,providing references for the design and construction of similar projects.
connecting passageopen-cut constructionnumerical simulationdisplacement change lawinternal force influencepost-construction analysis
万方数据
维普
