【作者】 李晓伟；

【导师】 曾巧玲；

【作者基本信息】 北京交通大学 ， 岩土工程， 2010， 硕士

【摘要】 地铁开挖引起的地层变形与应力释放必然会对周围环境产生一定程度的扰动,由于城市环境的复杂性,特别是北京以立交环路为主要地面交通形式的城市中,地铁施工将会不可避免的穿越大量既有桥基,对其正常使用产生影响。随着北京地区地铁新线建设高峰的到来,这种情况将会越来越多,因此研究地铁开挖对邻近桩基的影响具有重要的现实意义。本文以北京地铁国贸站为工程背景,抽象出计算模型。通过数值模拟,分析了地铁洞桩法施工对邻近单桩及群桩的影响规律,并对单桩及群桩进行了对比分析。分析隧道开挖作用下桩基承载力的可靠度,通过响应面法求解承载力损失的统计特征,并结合JC法求出桩基承载力的可靠度指标及可靠度,分析了一些变量对桩基承载力可靠度的影响。介绍地铁邻近桩基施工的三种加固措施,包括隔断措施,土体加固,桩基补强与托换。以设置隔断桩加固为例,对其加固效果进行分析。更多还原

【Abstract】 Surrounding environment disturbed by the ground deformation and stress relieving induced by metro excavation. Especially in Beijing which the main ground traffic style is based on overpass and ring road, many existing overpasses will be crossed by tunnels and the normal use of them will be affected inevitably. As new construction climax of the metro lines is coming in Beijing now, the number of this phenomenon is increasing, and the following situation will become sharper. So it’s very important to study on the inflluence of metro tunneling on adjacent pile foundation.The paper is based on engineering background of the Beijing Guomao subway station, abstracting the computation model. Through numerical simulation, study the influence of adjacent single pile and pile group by metro tunneling with PBA method and comparative analysis the single pile and pile group.Analysis the reliability of pile foundation bearing capacity by tunnel excavation, through the response surface method to solve the statistical characteristics of capacity loss. Use JC method work out the reliability index and reliability of pile bearing capacity and analyzing how some variables affect the reliability of bearing capacity.Introduce three kinds of reinforcement measures to the adjacent pile foundation with subway construction.Including partition measures, soil consolidation, pile reinforcement and underpinning. Take setting the partition piles for example, analysis the effects of the reinforcement.更多还原