软土地区深基坑开挖对邻近既有铁路的影响分析

Analysis of the Influence of Deep Foundation Excavation in Soft Soils on Adjacent Existing Railway

在邻近既有铁路的软土地区,深基坑开挖容易引起不可控的周边地表沉降,导致既有铁路线路产生偏差,从而影响其正常运营。目前,对软土地区既有铁路附近深基坑开挖影响的研究尚未引起广泛关注,并且缺乏相关设计和监测数据。以上海地区某邻近既有铁路的深基坑工程为例,对深基坑开挖对既有铁路的影响进行研究,分析表明:(1)对邻近铁路侧的基坑支护结构应根据变形控制和增加支护刚度的方案进行设计,以减少路基的沉降;(2)随着深基坑的开挖,铁路路基沉降曲线速率先增大后减小,最终沉降量较大;(3)基坑设计经验可供邻近既有铁路基坑设计、施工借鉴。

The excavation of deep foundation pit adjacent to the existing railway in soft soil area is easy to induce the uncontrollable surrounding ground subsidence,resulting in the misalignment of the existing railway line,thus affecting its normal operation.At present,the impact analysis of the deep excavation near the existing railway in soft soil area has not attracted wide attention,and there is a lack of the correspondent design and monitoring data.In this paper,a deep excavation adjacent to the existing railway in Shanghai is taken as an example to study the influence of the deep excavation on the existing railway.The research results show that:(1)The deep excavation supporting structure near railway side should be designed according to the deformation control and increasing supporting stiffness to reduce the settlement of the railway subgrade;(2)With the excavation of deep foundation,the settlement rate curve of the railway subgrade first increases and then decreases,and the final settlement is large;(3)This paper can be used as the reference for the similar design and construction of deep foundation adjacent to the existing railway.