摘要
为规避有限单元法分析基坑开挖位移场中存在的参数取值及边界条件不确定带来的计算结果可靠性不足的问题,运用已知或其他可靠方法得到的边界位移,采用间接边界单元法推求基坑开挖位移场及其对邻近地铁隧道的影响。基于平面荷载结构模型计算结果及工程实测结果的可靠性事实,假设在基坑围护挡土墙边界上作用按某种分布规律的虚拟力,同时考虑基坑围护挡土墙的位移边界条件。分析结果表明利用平面计算或监测的可靠数据推算基坑周边位移场是一个可靠途径;而且在一般的计算机上就可以分析一些大型基坑开挖引起的土层位移场及其对邻近建筑的影响,尤其该方法满足了邻近运营中地铁位移动态预测的高准确性要求,采用该方法具有快速、实用简便、准确等特点,因此具有广泛的工程应用前景。
To avoid the shortages in reliability of displacement field of the excavation calculated with the finite element method, in which the model parameters and boundary conditions are quite difficult to be determined, boundary displacements were obtained by measurement of other reliable methods, and the ground displacement field and its effect on adjacent metro tunnel were determined with the indirect boundary element method. Based on a large amount of engineering practice, the lateral displacement resulted from load-structure model often applied in design process was accepted by most engineers in China. So, with the credible data of load structure model or field measurements, and considering the boundary conditions of displacement of the excavation along the vertical length of retaining wall, an assumption was adopted that the fictitious forces with a certain distribution act along the side boundary of excavation. The results show that it is a credible approach to predict the displacement utilizing the calculation of plane program or reliable measured data. The displacement field of soil and its effect on adjacent structures can be analyzed efficiently with high accuracy using personal computers.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2005年第7期800-803,共4页
Chinese Journal of Geotechnical Engineering
关键词
边界单元法
基坑开挖
周边位移场
邻近地铁隧道
boundary element method
excavation
ground displacement field
adjacent subway tunnel
