摘要
软土地区基坑开挖导致周边土体变形,进而引发邻近结构物沉降,而高速铁路路基对沉降变形要求严格。基于某高铁站房基坑工程邻近运营杭长高铁工程实例,采用PLAXIS有限元软件建殳基坑开挖全过程分析模型,对基坑开挖引起的围护结构及邻近高铁路基变形进行研究,并结合现场实测数据对有限元计算结果进行验证。结果表明,围护结构和铁路路基沉降均在允许变形范围内,高压旋喷桩等坑底加固措施可有效减小围护结构变形和铁路路基沉降;铁路路基沉降量随基坑开挖深度的增加而增大,开挖引起铁路范围内路基最大沉降为4.19 mm;基坑开挖导致周边土体沉降,其主要影响范围为0.5-2倍的开挖深度。
The foundation pit excavation in soft soil area leads to the deformation of surrounding soil,which further leads to the settlement of adjacent structures,while subgrade of high-speed railway has strict requirements on settlement and defonnation.Based on a high-speed railway station foundation pit engineering nearby the operating Hangzhou-Changsha High-speed Railway,a finite element model containing whole process of foundation pit excavation,which was established by use of the software PLAXIS to study the influence of deep foundation pit excavation on the deformation of retaining structure and adjacent highspeed railway subgrade,and the finite element calculation results were verified by combining with the field measured data.The results show that the settlement of supporting structure and railway subgrade is within the allowable deformation range,and the pit bottom reinforcement measures such as high-pressure jet grouting pile can effectively reduce the defbimation of retaining structure and the settlement of railway subgrade.The settlement of railway subgrade increases with the depth of excavation,and the maximum settlement of subgrade within the scope of railway caused by excavation is 4.19 mm.The excavation of foundation pit in soft soil area results in the settlement of surrounding soil,and its main influence range is 0.5~2 times of excavation depth.
作者
徐俊
XU Jun(China Railway Shanghai Group Co.Ltd.,Shanghai 200071,China)
出处
《铁道建筑技术》
2020年第10期42-45,88,共5页
Railway Construction Technology
基金
上海铁路局科研计划课题(2013091)。
关键词
深基坑开挖
有限元模拟
路基沉降
现场监测
数据对比
deep foundation pit excavation
FEM simulation
subgrade settlement
field monitoring
data comparison
