聚合物泥浆在超深地下连续墙施工中的应用

随着城市轨道交通工程及地下空间工程的迅速发展,深大型基坑工程开始不断涌现,该类基坑主要有开挖深度深,开挖面积大等特点。地下连续墙作为富水、自稳性差地层基坑的主要支护形式,其围护嵌入深度也随着深大型基坑的出现而越来越深。依托昆明轨道交通4号线火车北站工程,阐述护壁泥浆作用机理,并通过现场试验分析研究聚合物泥浆在地下连续墙施工过程中控制槽壁稳定性的作用。火车北站工程地下连续墙最深达70 m,厚度为1.5m,在国内同等宽度的地下连续墙中深度尚属首例。研究成果表明,聚丙烯酸钠泥浆在类似地下连续墙施工中具有良好的护壁性能,这对类似地下连续墙施工过程中槽壁稳定性控制具有重要的参考意义。

Application of Polymer Slurry in Construction of Ultra-deep Underground Diaphragm Wall

With the rapid development of urban rail transit engineering and underground space engineering, deep and large foundation pits are continuously emerging. These types of foundations are mainly characterized by an increased excavation depth and a large excavation area. The diaphragm wall is the main form of support for foundation pits in water-rich and self-stabilized strata. The embedded depth of its enclosure is getting deeper and deeper with the appearance of deep and large foundation pit. Based on the North Railway Station of Kunming Rail Transit Line 4, this paper describes the mechanism of wall slurry action and discusses the function of a polymer slurry in controlling the stability of the groove wall during the construction of a diaphragm wall using data from field tests. The diaphragm wall of the North Railway Station project has a depth of nearly 70 m, with a thickness of 1.5 m. The results show that sodium polyacrylate mud exhibits a good wall protection performance in the construction of a diaphragm wall similar to that constructed at the railway station. This has important reference significance for the stability control of groove walls in the construction process of diaphragm walls.