盾构并行穿越施工对既有隧道影响分析与关键技术

以昆明轨道交通4号线左右线并行下穿既有昆明轨道交通2号线工程为背景,结合数值模拟以及现场监测等方法,研究近接施工对既有隧道以及周围地层的影响规律,提出盾构近接相关的施工控制技术。首先,建立新建盾构隧道下穿既有盾构区间的三维有限差分计算模型,通过计算分析最终选择先下方区间、再上方区间的施工顺序,对既有结构及地层的扰动最小;其次,在现场建立试验段积累在类似下穿段地层中的盾构掘进经验,确定盾构下穿2号线的施工参数,并验证克泥效工艺的效果;最后,通过将现场监测数据并与数值模拟结果进行对比和分析,验证数值模拟的准确性和合理性,建议工程中加强信息化施工和相关施工优化措施,以保证2号线地铁盾构隧道及地铁车站的结构安全和正常运营。

Influence Analysis and Key Technology Research of Shield Tunnel Parallel Crossing Construction under Existing Tunnels

Based on the project of Kunming Rail Transit Line 4 crossing existing Kunming Rail Transit Line 2 in parallel, combined with numerical simulation and field monitoring, this paper studies the influence of adjacent construction on existing tunnels and surrounding strata, and puts forward the construction control technology of shield tunneling adjacency. Firstly, a three-dimensional finite difference calculation model for new shield tunnels passing through existing shield tunnels is established. Through calculation and analysis, the construction sequence of the first lower section and the second upper section is selected to minimize the disturbance to existing structures and strata; Secondly, the test section was set up in the field to accumulate the tunneling experience of shield tunneling in similar strata, the construction parameters of shield tunneling through line 2 were determined, and the effect of "clay shock method" technology was verified. Finally, the accuracy and rationality of the numerical simulation are verified by comparing and analyzing the field monitoring data with the numerical simulation results. It is suggested that informationization construction and related construction optimization measures should be strengthened in the project to ensure the effectiveness of the technology. Structural safety and normal operation of shield tunnel and metro station on Line 2.