摘要
针对北京地铁蒲天区间隧道桩基托换工程实际情况,采用增加隧道支护通过植筋、剥桩、托拱、断桩及再次托拱的方式进行洞内桩基托换,利用3D-σ有限元计算程序对其施工过程进行三维数值模拟,得到桩顶沉降、承台沉降和拱顶下沉值,发现隧道开挖过程中桩及上部承台基本上是均匀沉降,且沉降量较小;剥桩、断桩过程引起的桩基础沉降较大,剥桩、断桩为桩基托换工程的控制工序。
According to the actual project of pile underpinning in the inter-sectional tunnel between the Puhuangyu Station and the Tiantan-East Station of the Beijing Subway, the scheme of pile foundation underpinning is performed with tunnel supports added and several new techniques adopted, such as inserting reinforced bars, shelling piles, lining arch, truncating piles and secondary lining arch. With the 3-dimention numerical simulation of the constructing process calculated by the 3D-σ finite element program, the values of pile top settlement, pile cap settlement, and vault crown settlement are obtained, and it is found that the settlement of the middle of the pile and that of the pile cap in the process of the tunnel construction are uniform and the settling amount is small; the settling amount of the pile foundation during the construction of shelling piles and truncating piles is found comparatively large and thus the construction of shelling piles and truncating piles is found to be the key procedures.
出处
《国防交通工程与技术》
2008年第2期63-66,共4页
Traffic Engineering and Technology for National Defence
关键词
桩基托换
数值模拟
沉降
剥桩
断桩
pile foundation underpinning
numerical simulation
settlement
shelling piles
truncating piles
