摘要
针对地下室丰富、存在巨厚粉细砂层地质条件下的超深基坑施工,抗变形能力较强的地下连续墙是一种有效的支护与止水方案。依托北京城市副中心站综合交通枢纽工程Ⅱ标段T形地下连续墙施工案例,为解决高承压水超厚砂层的孔壁坍塌、槽壁加固侵线、T形钢筋笼加工与吊装难度大、超厚砂层泥浆沉渣处理以及混凝土灌注要求高等问题,提出并应用了旋挖钻机引孔成槽、钢筋笼加工与吊点优化设置、沉淀法结合置换法处理沉渣以及3个导管同步灌注混凝土等针对性的控制措施,最终顺利保证了超深T形地下连续墙在巨厚砂层中的施工质量。
The diaphragm wall with strong deformation resistance is an effective support and water stop scheme for the construction of ultra deep foundation pit under the geological conditions of rich basement and extremely thick silty sand layer.Relying on the construction case of T-shaped diaphragm wall in bid section Il of Beijing sub-center railway station comprehensive transportation hub project,in order to solve the problems of hole wall collapse,groove wall reinforcement invasion,T-shaped reinforcement cage processing and hoisting difficulty,slurry sediment treatment of super thick sand layer,and high requirements for concrete pouring,the rotary dilling rig is put forward and applied to guide holes and form grooves,reinforcement cage processing and optimization of lifting points,thetargeted control measures are proposed and applied,such as slot formation by rotary drilling machines,optimization of steel cage processing and lifting points,sedimentation method combined with displacement method for treating sediment,and synchronous pouring of concrete through three conduits.Finally,the construction quality of the ultra deep T-shaped diaphragm wall in the huge thick sand layer is successfully guaranteed.
作者
何小飞
HE Xiaofei(Beijing Urban Construction Huaxia Infrastructure Engineering Co.,Ltd.,Beijing 101116,China)
出处
《建筑施工》
2023年第8期1513-1516,共4页
Building Construction
关键词
巨厚砂层
T形地下连续墙
超深基坑
关键措施
extremely thick sand layer
T-shaped diaphragm wall
ultra deep foundation pit
key measures
