借鉴在石油工业中得到有效应用的超声波技术,自主研制了适用于砂土地基堤防减压井的超声波解堵系统。在室内大型渗透仪中模拟了减压井倒灌淤堵过程,采用自制超声波设备进行了解堵试验,并通过常水头渗透试验分析了超声波技术作用效果,研究了试验砂样装样密度和驱动水力比降对超声波解堵效果的影响。试验结果表明:倒灌悬浊液使得试样含水层发生了堵塞,井管排水能力减弱,承压水头增加;经超声波解堵后,减压井及其周边含水层综合渗透性得到提升,出水口流量增加,减压能力增强,超声波解堵效果明显,可使淤堵减压井恢复60%以上。减小装样密度使得砂样孔隙率增加,可提高淤堵前排水减压能力,但发生倒灌淤堵程度增加。装样密度对超声波解堵程度影响不显著,但在较小的装样密度下,超声波能在较短的时间内达到同等解堵效果。提高超声波解堵过程中驱动水力比降,更易于带动剥离的淤堵细颗粒从含水层孔隙中析出,能增加超声波解堵效果。

In the light of the ultrasonic technology which has been applied effectively in the petroleum industry, an ultrasonic plugging removal system which is suitable for dike relief well has been independently developed. The process of backward silting of the relief well was simulated in a large laboratory permeameter, and the self-developed ultrasonic equipment was employed to remove the plug. The effect of the proposed ultrasonic technology was studied through permeation test with constant water head, and the influence of sand sample density and driving hydraulic gradient on the effect of ultrasonic technology were also studied. The experimental results revealed that the aquifer was blocked by the reversed filling suspension. The drainage capacity of relief well dropped, and the artesian head rose. After the plugging removal using the self-developed ultrasonic technology, the permeability of the relief well and surrounding aquifer was enhanced, the outlet flow of relief well pipe increased, and the decompression ability was ameliorated. The relief well recovered by over 60% using the present ultrasonic technology. In addition, reducing the density of sand sample raised the porosity of sand sample and boosted the drainage and decompression capacity before silting, but the silting degree could aggravate. The density of sand sample had no significant effect on the degree of ultrasonic plugging removal. However, with small sample density, ultrasonic technology can achieve equal plugging removal effect in a short time. Escalating the driving hydraulic gradient in the process of ultrasonic de-plugging could help upgrade the ultrasonic effect by prompting the exfoliated silt fine particles to precipitate out from the aquifer.