一种结合弹性波CT正演模拟与钻孔注水法的防渗墙检测方法研究

Research on Impervious Wall Detection Technology Based on Forward Simulation Technology

摘要:

防渗墙是水利水电工程项目中的重要部分,随着防渗墙规模的逐渐扩大,常规防渗墙检测方法逐渐减少。为了增加防渗墙的检测手段,研究提出采用弹性波CT正演模拟技术,与钻孔注水法相结合,在钻孔注水试验时,利用弹性波CT正演模拟技术,检测水流在墙体中的流动情况,从而实现在检测防渗墙渗透性的同时,完成防渗墙的完整性检测。结果显示,在低速或高速异常速度模型中,走时残差的波动较大,且完全不同,采用围井法,实验深度为15m时,计算得到的渗透系数为0.14*10-6cm/s,采用常水头法,深度为15m时,该方法计算得到的渗透系数为1.88*10-6cm/s,基于弹性波CT正演模拟技术,可以有效地反映防渗墙的状态,采用围井法检测得到的防渗墙渗透系数,低于采用常水头注水法得到的渗透系数。研究提出的方法可以准确地检测防渗墙的质量。

Abstract:

The anti-seepage wall is an important part of water conservancy and hydropower engineering projects. With the gradual expansion of the scale of the anti-seepage wall, the conventional detection methods for the anti-seepage wall are gradually decreasing. In order to increase the detection methods for the A-Ji anti-seepage wall, the study proposes to use elastic wave CT forward simulation technology, combined with drilling and water injection method, to detect the integrity and permeability of the anti-seepage wall. Elastic wave CT forward simulation technology is a type of tomography detection method that can be used to detect the integrity of anti-seepage walls. The drilling water injection method is divided into constant head water injection method and enclosure well method, which can both detect the permeability of anti-seepage walls. The results show that in low-speed or high-speed abnormal velocity models, the fluctuation of travel time residuals is significant and completely different. The enclosure method is used, and the calculated permeability coefficient is 0.14 * 10-6cm/s at a depth of 15m. The constant head method is used, and the calculated permeability coefficient is 1.88 * 10-6cm/s at a depth of 15m. Based on elastic wave CT forward simulation technology, it can effectively reflect the state of the anti-seepage wall, The permeability coefficient of the anti-seepage wall detected by the enclosure method is lower than that obtained by the constant head water injection method. The method proposed in the study can accurately detect the quality of anti-seepage walls.