振孔高喷灌浆在三峡工程中的应用

Application of Vibrating-Hole Jet Grouting Technology to TGP

三峡工程电源电站施工围堰防渗采取了振孔高喷防渗墙的形式。振孔高喷防渗墙是采用高压喷射注浆技术构筑的连续板墙状凝结体结构。振孔高压喷射注浆是一种钻喷一体化的高喷灌浆技术,以大功率的振动锤将带有特制喷嘴的高喷杆快速向下振孔,同时用高压设备使浆液、水及气成为高压流从喷嘴中喷射出来,冲击、破坏土体。当钻杆到达预定岩面后,以一定速度向上提升钻杆,使浆液与风化砂强制混合,待浆液凝固后,便形成了防渗墙。检测表明,三峡工程电源电站施工围堰高喷防渗墙施工质量优量,各项性能均满足设计要求。

The vibrating-hole jet grouted cut-off wall has been applied to the construction cofferdam for the power resource station at the Three Gorges project (TGP). The vibrating-hole jet grouted cut-off wall made of continuous coagulated plate wall structure is built by high pressure jetting grout technology. The vibrating-hole jet grouting is a kind of jet grout technology with integrity of drilling and shotconcreting. While the jetting bar with special nozzle lowers down rapidly by powerful vibrating hammer, the high pressure device makes grout, water and air become a high pressure flow and jet out from the nozzle, which strongly impacts and destroys soil body. When drill bar reaches down to the presumptive rock surface, it will be lifted up at certain speed to make grout be mixed with weathered sand forcedly; when grout consolidates, a wall has been formed. It has been shown based on inspection that the construction quality of the vibrating-hole jet grouted cut-off wall in the construction cofferdam at TGP is excellent and all its performance indexes can meet the design requirements.