优化基底土体尺寸对围护结构的影响研究

Research on Influence of Optimizing Size of Basement Soil on Retaining Structure

通过优化基坑内被动土体的方式减小围护结构的水平位移。该方法是通过施工工艺来改变基坑被动土体的力学性质,从而提高被处理土体的物理力学性能。以某地区地铁车站开挖为案例,利用FLAC3D软件建立三维模型,模拟基坑开挖过程,研究加固体的宽度、深度对基坑围护结构水平位移变形规律的影响。结果表明:在加固深度不大于4.5 m时,可以有效地减小地连墙的水平位移,但当加固深度大于4.5 m时,加固带来的优化效果不明显;当采用相同加固宽度时,加固深度不大于4.5 m时,加固宽度不大于6.0 m优化效果明显,加固深度大于4.5 m时,加固宽度大于6.0 m优化效果明显;同时,在特定地连墙围护结构水平位移下,找到了优化宽度和深度之间的二次关系式。

It is reduced the horizontal displacement of retaining structure by optimizing passive soil in foundation pit.The method is to change the mechanical properties of passive soil in foundation pit by means of construction technology so as to improve the physical and mechanical performance of the soil mass to be treated.In the excavation of a subway station in certain area taken as an example,FLAC3D software was used to establish a three-dimensional model to simulate the excavation process of the foundation pit,and then to study the influence of the width and depth of reinforced soil body on the horizontal displacement and deformation law of the foundation pit retaining structure.The results show that,when the depth of reinforcement is within 4.5 m,the horizontal displacement of the underground continuous wall can be effectively reduced,but when the depth of reinforcement exceeds 4.5 m,the optimization effect brought by the reinforcement is not obvious;when the same width of reinforcement is applied,the width of reinforcement less than 6m contributes to obvious optimization effect when the depth of reinforcement is less than 4.5 m,while the width more than 6.0 m to obvious optimization effect when the depth is greater than 4.5 m.At the same time,under a specific horizontal displacement of the retaining structure of the continuous wall,the quadratic relationship between the width and the depth of the optimization was found out.