带嵌岩锁脚桩的地下连续墙施工技术研究与应用

Construction Technology Research on Underground Continuous Wall with Rock-Embedded Lock Foot Piles and It's Application

结合某地铁深基坑工程中部分槽段地下连续墙入岩及岩面低于基坑开挖底面的工程特点,从基坑安全、成本、进度等多方面考虑,针对基坑连续墙所深入的岩面上部采用液压抓斗成槽机取土成槽,岩面下部使用冲击钻均匀冲击出若干圆孔,再通过槽内多次清底、特制圆形与方形钢筋笼对接和特殊混凝土浇筑等技术,形成上墙下桩的非常规嵌岩形式地下连续墙。通过对该施工技术的研究与应用,证明该项新的施工方法安全有效,并取得了可观的经济和社会效益。

Based on the characteristics of underground continuous wall embedded in the rock and the surface of the rock being under the bottom of the pit,in some slots of a metro deep pit project,taking pit safety,cost,schedule and so on into consideration,hydraulic bucket trench machines were employed to grab dirt to form slots for the upper part of the rock,then impacting drills were adopted to punch out circular holes for the lower part of the rock. After several times bottom clearing,adopting specially-made butt joints of round and square reinforcement cages and special concreting,an unconventional form of rock-embedded underground continuous wall with piles below was formed. The new construction method had been proved to be safe and effective,achieving considerable economic and social benefits.