二重管垂直注浆技术及注浆机理探讨

Technique and mechanism of double rod vertical injection grouting

在富水砂层和全风化花岗岩为主的软弱不均地层中进行基坑开挖,为了防止开挖过程中由于坑壁渗漏水造成基坑失稳、坍塌、管涌等灾害,除采取适当的支护措施外,还须对基坑周边进行止水处理,限制地下水向基坑内的流动,常用的注浆止水方法有袖阀管注浆和二重管注浆法。二重管注浆是采用特殊的双重钻杆钻孔,并通过钻杆进行注浆,浆液在钻杆端部的混合器混合,具有钻注一体的特点。针对工程地层条件,选取二重管垂直注浆技术对桩间进行止水处理,介绍了注浆工艺及参数,并对其注浆机理进行了探讨。

With regard to the excavation of foundation pits in the water-rich sand and decomposed granite mainly consisting of soft weak uneven strata,in order to prevent the wall instability caused by water leakage,collapse,piping and other disasters, sealing works should be made around the pit so as to restrict groundwater flowing into the pit besides appropriate supporting measures.The grouting sleeve valve and the double rod injection grouting are common sealing methods.The double rod injection grouting employs the special double drill pipe to drill and grout,and the slurry in the blender is mixed at the end of the drill pipe.The double rod vertical injection grouting technology was introduced,and the grouting mechanism was discussed.