旋喷特制PVC管护壁施工技术在易塌地层的应用

Application of jet grouting special PVC pipe wall protection technique in sloughing formation

高压旋喷桩在基坑围护工程中得到广泛应用,针对细砂、卵砂、砂砾等易塌地层进行钻进引孔普遍存在塌孔卡钻情况,通过联泰A-19-1地块基坑支护工程项目施工,提出采用特制PVC管进行护壁防塌孔以及喷浆破碎压力等关键技术,解决了高压旋喷桩在易塌地层施工的难题,该基坑围护止水防渗达到设计及施工要求。

High-pressure jet grouting pile technique is widely used in foundation pit retaining engineering. However,for sloughing formations,such as formation with fine sand,pebble,or gravel,while drilling a borehole for the pile grouting,the drill bit is frequently stuck due to the collapse of borehole wall. In the paper,the construction of foundation pit retaining and protection project of Liantai A-19-1 block was taken as an instance,to illustrate how this problem is solved by the application of specially fabricated PVC pipe,which is capable of prevent the borehole wall from collapsing,and technique of fracturing pressure of jet grouting. The result shows that the effect of sealing met the requirements of design and construction.