基于等效原理的型钢水泥土搅拌墙在堤坝排水管沟漕基坑开挖支护中的应用

针对沿河流中被填土隔断的堤坝走向布置的市政排水管沟漕基坑开挖支护问题,提出采用型钢水泥土搅拌墙支护方案。为解决按单排柱列式排列组成的内插型钢水泥土搅拌桩等效成型钢水泥土搅拌墙的计算理论问题,以及堤坝两侧的河水水压力对基坑稳定影响问题。根据相应的基坑设计规范,假设型钢水泥土搅拌桩墙是弹性材料,借助等效原理,使用MIDAS/GTSNX数值模拟软件将河水水压力和等效原理结合起来,建立型钢水泥土搅拌墙在堤坝排水管沟漕基坑开挖支护中应用的数值模型进行基于强度折减法的稳定性分析和变形计算,利用最小安全系数、现场监测数据、监测报警值和最大基坑计算变形限制值进行基坑稳定的判别。

Application of Shaped Steel Soil-cement Mixing Wall Based on the Equivalence Principle in Excavation and Support of Dam Drain-pipe Trench Foundation Pit

Focusing on the problem of excavation and support of municipal drain-pipe trench foundation pit,which was arranged along the direction of the dam which was divided by the filling soil in the river,this paper proposed the supporting scheme which adopted shaped steel soil-cement mixing wall.In order to solve the problem of computation theory that inserted steel soil-cement mixing pile arranged and composed in a single column was equivalent to shaped steel soil-cement mixing wall,and the influence of the river water pressure on the stability of foundation pit.According to the corresponding design specification of foundation pit,and assuming shaped steel soil-cement mixing pile wall was elastic material,by means of equivalence principle,using MIDAS/GTS NX numerical simulation software to combine river water pressure and equivalence principle,the numerical model of the application of shaped steel soil-cement mixing wall in excavation and support of dam drain-pipe trench foundation pit was developed to analyze the stability based on the strength reduction method and deformation results by using the minimum factor of safety,field monitoring data,monitoring alarm value and the limited value of the maximum calculated deformation of foundation pit for criterion of foundation pit stability.