南宁地铁深基坑开挖风险影响技术研究

Study on risk impact of deep foundation pit excavation in Nanning Metro

临近地铁轨道的深基坑受开挖影响而产生位移和变形,这将影响到轨道交通的运营安全.以南宁地铁某深基坑为背景,结合数值模拟等分析手段,通过建立三维模型,预测基坑的开挖对地铁联络线区间造成的影响以及危害,从而为指导基坑工程的设计、施工以及施工过程中的加固和监测提供参考.结果表明,深基坑大规模开挖情况下,产生的卸荷效应明显,会对已经运营的地铁区间产生一定的影响,引起隧道的水平与竖向变形,但在采取有针对性的支撑方案的情况下,可以将变形降低至安全限值以下.

The displacement and deformation of deep foundation pit adjacent to metro track caused by excavation will affect the operation safety of metro.Taking a deep foundation pit of Nanning Metro as the background,combined with numerical simulation and other analytical means,through the establishment of a three-dimensional model,the impact and harm of excavation of foundation pit on the metro tie-line area are predicted,so as to guide the design,construction and construction of foundation pit engineering.The results show that the unloading effect of large-scale excavation of deep foundation pit is obvious,which will have a certain impact on the already operated metro section and cause the horizontal and vertical deformation of the tunnel,but the deformation can be reduced to below the safety limit under the condition of adopting the pertinent supporting scheme.