钢套筒压入对邻近地铁影响的有限元分析

Finite element analysis of the influence of steel sleeve pressing on adjacent subway

为研究桩基施工过程中钢套筒压入对邻近地铁产生的扰动,利用Midas GTS有限元软件,对钢套筒的压入过程进行数值模拟,并针对其施工顺序及钢套筒−土界面单元参数的影响进行了分析。研究结果表明:钢套筒压入引起的邻近地铁变形在允许范围之内,全套管灌注桩适用于近地铁的桩基施工;采用隧道两侧钢套筒对称施工的方法可减小对邻近邻地铁的扰动;邻近地铁结构的位移对钢套筒−土界面单元中的摩擦角和黏聚力十分敏感,地铁隧道的变形量随着二者取值的增大而显著提高。实际工程可采取改善钢套筒与土体边界条件的方法,从而减小钢套筒施工对紧邻地铁产生的不利影响。

In order to investigate the impact of disturbance of the steel sleeve on adjacent subway during the construction of the pile foundation,the finite element software MIDAS GTS was used to simulate the press-in process of steel sleeve.The influence of construction sequence and the interface parameter of steel sleeve and soil on the deformation of the subway was analyzed.The results show that,the deformation of the adjacent subway caused by the press-in of steel sleeve is permitted and accepted,the full-sleeve caisson pile is a suitable pile foundation near subway.The impact of construction disturbance on adjacent subway can be decreased,when the steel sleeve is constructed symmetrical on the both side of the tunnel.The displacement of the subway structure is sensitive to the friction angle and cohesion of the interface unit of steel sleeve and soil.The deformation of the subway tunnel increases significantly with the increase of those parameters.The adverse effect of steel sleeve construction on tunnel can be reduced,when the interface parameter of steel sleeve and soil was improved.