暗挖地铁隧道斜交下穿既有铁路的施工研究

Study on Construction of Subsurface Excavated Metro Tunnel Under-passing Existing Railway

研究目的:新建地铁隧道下穿既有铁路工程涉及到铁路运营安全和地铁施工安全,受到工程界的重视。文中选取暗挖地铁隧道斜交下穿某既有铁路工程为研究对象,该地铁隧道为双线、部分浅埋隧道,隧道采用暗挖法施工难度和风险较大。通过ansys计算软件按初步设计的施工顺序和施工工艺进行三维数值计算,分析隧道施工引起的地层沉降和塑性区分布。研究结论:(1)隧道施工引起地层内力重分布,是地表产生沉降的原因,但是列车荷载对地表沉降的影响更为显著;(2)数值计算对施工措施的选择提供了重要依据;(3)施工前对铁路路基注浆加固或在铁路路基两侧预埋袖阀管根据沉降情况进行注浆,可对沉降变形进行控制。

Research purposes： Construction of the metro tunnel under - passing the existing railway is related to the railway traffic safety and the metro construction safety. So the more attention is paid to such construction. In this paper, taking one subsurface excavated metro double track tunnel with shallow part as an example, the three - dimensional numerical calculation was made for the designed construction order and construction technology with the ANSYS calculation software, and the analysis was made for the stratum settlement and its distribution. Research conclusions： The analysis showed the internal force in the stratum caused by the tunnel construction was redistributed and this was the reason for the ground settlement. However, the train load had bigger influence on the ground settlement. The numerical calculation could provide the important basis for selection of the construction measures. If the grouting was conducted to the railway subgrade before construction or the grouting was conducted through the sleeve valve bedded on both sides of the subgrade, the settlement deformation could be controlled.