孔隙砂岩多次化学注浆试验研究

选取宁东地区典型的孔隙砂岩,采用不同颜色示踪的化学浆液进行4次注浆试验;揭示了浆液在孔隙中的扩散、充填规律及注浆次数与被注岩层渗透系数、孔隙率之间的关系。研究发现:每次化学注浆浆液的充填情况有明显的差别,首次注浆浆液在整个岩样均有较均匀的充填,后续的各次注浆浆液均呈现部分区域积聚充填的现象;随着注浆次数的增加岩样的渗透系数减小,孔隙充填率增加,渗透系数、孔隙充填率与注浆次数的关系可分别采用幂函数及对数函数拟合;4次注浆后岩样的渗透系数减小了97%,说明多次注浆起到了很好的减渗效果。依据试验成果,建立数值计算模型,预测了不同注浆次数、不同开挖条件下注浆孔及井筒的涌水量,并与井筒实际涌水量进行对比,发现两者数据较为吻合,说明依据试验结果建立数值模型进行涌水量预测是可行的。

Research on multiple chemical grouting experiment of porous sandstone

Four multiple grouting model tests have been finished with slurry tracked by different colors, by using typical porous sandstone selected in Ningdong. It reveals the law of diffusion and filling of slurry in pores, and the relationship between repetitions of grouting and permeability coefficient and porosity of the injected rock and soil mass. The studies found: the filling state of grout is obviously different from others in each single grouting of the multiple grouting test, the slurry of the first time grouting has more uniform filling in the entire profile, while the slurry shows accumulation of filling partly. In the experiment, the more the times of grouting is, the smaller the permeability coefficient of the model material and the greater the filling rate of pores will be. The relation between the permeability coefficient, filling rate of pores and number of repetitions of grouting can be fitted respectively by power function, and logarithmic function. The permeability coefficient of the model material is reduced by 97% after grouting for four times, which means that multiple grouting indeed has an influence on infiltration reduction. According to the test results, a numerical model is established to predict the water inflow of grouting holes and shaft with different grouting times and pore filling rate; and the water inflow of shaft is compared with the actual situation. The results are fairly consistent each other. showing that it is feasible to predict the water inflow by using numerical mode and basis of test results.