齐古水库放水洞工作闸井井壁基岩坍塌处理

介绍了齐古水库放水隧洞工作闸井井筒开挖后围岩垮塌事故处理。该竖井井筒在软岩中开挖形成。竖井井筒及下游隧洞洞室在头一年开挖完成后,仅做了临时钢筋混凝土喷护处理,放置一个冬季,约4个月。第二年春季雪水融化后,在闸井下游面与平洞衔接部位发生垮塌。为防止进一步垮塌,采用砂砾石将整个竖井回填,然后采用钢筋混凝土倒挂井进行井筒围岩固壁,再进行工作闸井的正常施工。倒挂井对于软岩围岩的闸井塌方处理具有效果明显、施工便利、造价少的特点,可在同类地基基础处理中推广应用。

Treatment of bed rock collapse from wall of working gate shaft for water releasing tunnel of Qigu Reservoir

The accident treatment of the surrounding rock collapse after the excavation of the shaft for the working gate of the water releasing tunnel of Qigu Reservoir is described herein. The shaft is excavated in soft rock. Both the shaft and the downstream chamber of the tunnel are only treated with the temporary protection of reinforced shotcrete after the excavation in the last year and then laid up for a winter that is about four months. After snow melting in the spring of the next year， collapse occurs at the joint between the downstream face of the gate shaft and the adit. In order to prevent the further collapse， the whole shaft is backfilled with sandy gravel. Whereafter， the surrounding rock of the shaft is reinforced by the technology of reinforced concrete upside-down well， and then the working gate shaft is normally constructed. The technology of upside-down well has an obvious effect for dealing with the gate shaft collapse occurred in soft surrounding rock with the characteristics of convenient construction and less construction cost， thus can be popularized and applied to the similar foundation treatment.