竖向分层浇筑特深地下连续墙施工技术研究北大核心CSCD

上海苏州河深隧工程采用双道特深地下连续墙作为围护结构及隔水帷幕,墙体深度为103～105m,墙身材料为C35 (水下)混凝土。在盾构进出洞位置,外圈止水帷幕地墙需要满足盾构刀盘直接切削的需求,因此该段地墙结构选择M30高强度砂浆材料灌注。文章采用直径1 m钻孔灌注桩,现场模拟了混凝土-砂浆-混凝土以及混凝土-砂浆两种工况条件下的水下浇筑特性,并通过中心取芯的方式获得了水下竖向分层浇筑的桩体结构的材料界面位置与浇筑方法的关系。取芯结果表明,采用文章提出的浇筑方法可以形成连续密实的桩体结构,交界面芯样的轴心抗压强度不低于M30。试验验证了竖向分层浇筑方法在超深地墙施工中的可行性。

Research on Vertical Layered Construction Method of the Extra-Deep Diaphragm Wall

The two extra-deep diaphragm walls are adopted as the closure structure and water sealing curtain in the Suzhou river water-storage and drainage tunnel project. The maximum depth of the diaphragm wall is 103 m to 105 m and the main material of the diaphragm wall is C35 concrete (beneath water). In order to meet the needs of shield construction, the middle part material of the diaphragm wall is replaced by M30 mortar. In this paper, two kinds of casting method are tested by means of two experimental boring piles (T1 m). One type is concretemortar- concrete and the other is concrete-mortar. By core drilling, the relationship between the casting method and the interface position of concrete and mortar is obtained. Samples from core drilling indicate that the casting method can provide a continuous and dense pile structure, and the axial compressive strength of the sample cored form the pile interface is not less than that of M30 mortar. The feasibility of vertical layered concrete casting method in diaphragm wall construction is verified. © 2018, Editorial Office of Modern Tunnelling Technology. All right reserved.