地下工程裂隙型涌水超前注浆治理方法

Pre-excavation Grouting to Prevent Water Inflow of Jointed Rock in Underground Construction

针对地下工程裂隙型涌水超前注浆问题,通过钻探获取裂隙频率信息,并采用分段压水试验的方法,对围岩的渗透系数进行了测定;采用数理统计方法对所测数据进行分析,获得其统计规律;借助于涌水量计算理论,依据设计时确定的涌水量容许值,计算得到了所需封堵裂隙宽度的最小值,为注浆材料的选择提供依据;根据所选注浆材料分析了浆液扩散规律并确定了注浆方法与注浆参数;采用流动维度理论对注浆过程中PQT曲线进行了分析,并通过开挖检验对注浆封堵效果进行了评估.研究结果表明:拱顶与侧壁无明显渗水,涌水量小于0.01 m^3/h,达到了渗漏水控制标准以及注浆封堵的目标;实际开挖后的涌水量比预测值低50%,误差在合理范围内.

Fracture frequency information was acquired by drilling for pre-excavation grouting for underground construction fracture water inflow. The permeability coefficient of the surrounding rock mass was measured by pump-in tests on each section. The measured data were analysed by employing statistical methods to determine their statistical rules. According to the water inflow calculation theory,in combination with the designed water inflow control criterion,the minimum value for the fracture width to be sealed was calculated,which provides a criterion for the selection of grouting materials. According to this,the spreading rule was analysed,and grouting methods and parameters were determined. The flow dimension theory was used to analyse the pressure-quantitytime curves during grouting. After grouting,the sealing efficiency was evaluated by excavation. The results show that obvious water seepage existed in the vault and side walls, which reached requirement on seepage water control criterion of no more than 0.01 m^3/h. The actual water inflow was 50% lower than the predicted value, which was within the acceptable range.