地铁隧道盾构下穿既有砌体人防工程影响研究

Study on the Influence of Shield Tunneling of Subway Tunnel Under Existing Masonry Civil Air Defense Engineering

以郑州市某区间隧道下穿砌体人防工程为例,采用三维有限元对实际工程进行建模,对盾构双隧道下穿加固区砌体人防工程变形进行分析,考察盾构隧道施工产生的地表沉降及水平位移。结果表明,水泥砂浆填充显著减小了既有砌体人防结构位移,未填充区结构位移显著大于填充区,但都在允许范围内;双隧道相继开挖使得地表沉降曲线呈现不同姿态。通过有限元模型对地层及结构变形进行分析,可为今后类似盾构穿越施工提供参考。

Through taking an interval tunnel underpass masonry civil air defense project in Zhengzhou City as an example,3D finite element method is used to model the actual project,the deformation of gas civil air defense project in underpass reinforcement area of double shield tunnel is analyzed,and the surface settlement and horizontal displacement caused by shield tunnel construction are investigated.The results show that the cement mortar filling significantly reduces the displacement of the existing masonry civil air defense structure,and the structural displacement of the unfilled area is significantly larger than that of the filled area,but all of them are within the allowable range.Successive excavation of double tunnels results in different surface settlement curves.The analysis of stratum and structure deformation by finite element model can provide reference for similar shield crossing construction in the future.