影响深基坑围护墙内支撑系统因素的状况分析

Analysis on Influence Factors Condition of Internal Bracing System of Retaining Wall of Deep Foundation

在深基坑开挖过程中,内支撑对稳定基坑及控制基坑变形有重要意义。以某深基坑工程为研究背景,借助数值模拟方法建立了基坑开挖力学模型,考虑内支撑截面、支撑作用点位置、支撑作用点形式和支撑刚度四个影响因素,对内支撑对围护结构内力及变形的影响进行了探讨。分析结果表明:钢支撑截面的选择应视情况而定,且支撑长度不宜大于25 m;支撑位置的设置对支护结构受力及变形有较大影响,在基坑设计中应当予以重视;改进的内支撑作用点形式对改善基坑受力、控制基坑变形有积极作用;通过增加内支撑刚度的方式以减小基坑变形不是最有效的方法;研究成果可为工程实践及理论研究提供参考。

In the process of deep foundation pit excavation,the internal bracing for stable foundation pit and control deformation of foundation pit had significance influence. On the basis of the case study of the foundation pit,adopting the numerical simulation method to establish mechanical model of foundation pit excavation. The retaining structure internal force and deformation were discussed consideration support section,support position,support point form and support stiffness. The analysis results indicate that we should be selected reasonable steel support section,and the supporting length should not be greater than 25 m. Setting reasonable support position for the force and deformation of retaining structure had significance influence,and we should attach importance to it in foundation pit design. The improved internal bracing for improve force and control deformation had positive effect.By increasing the support stiffness in order to reduce the deformation of foundation pit wasn＇ t the most effective method. The conclusion could be referenced for engineering practice and theory research.