靠近渠堤的坑塘是影响和危害河渠工程安全的严重隐患之一。以引江济淮工程中涉及坑塘和膨胀土的某一河道为例,运用GeoStudio软件建立了耦合渗流和稳定性分析的河道边坡计算模型,并对该边坡提出了相应的支护方案,分析了边坡支护前后的抗滑稳定性,并研究了填塘范围、坑塘水深及土体渗透性对边坡渗流和稳定性的影响。研究结果表明:按支护方案进行支护后,各种工况下的渠道边坡稳定性均满足规范要求;填塘处理能够显著降低坑塘渗流在坡面的出溢点高程、减小渗漏单宽流量,进而提升河道边坡的稳定性;不同河道水位工况下,坑塘水深对坑塘水分在边坡内渗流和边坡稳定性的影响均较小;膨胀土渗透系数越低,坑塘渗流在坡面的出溢点高程越低,渗漏单宽流量也越低,安全系数越高,膨胀土渗透性对坑塘水分在边坡内渗流和边坡稳定性的影响均十分显著。研究成果可为类似河道边坡的支护设计、填塘处理提供参考和借鉴。

Ponds near canal embankment is a severe hidden danger affecting the safety of river canal project. With a river slope involving ponds and expansive soil in the Yangtze-to-Huaihe River Diversion Project as a case study, a numerical model coupling seepage and stability analysis for river slope was established by using GeoStudio software. Reinforcement measures were proposed, and the anti-sliding stability of the studied river slope before and after reinforcement was analyzed. Furthermore, the effects of pond filling treatment, pond water depth and soil permeability on the seepage and stability of the river slope are investigated. Results manifest that the reinforced river slope meet the requirements of stability specification under various working conditions. Pond filling treatment reduces remarkably the elevation of water outflow point of the pond and the unit width flow of leakage, hence improving the stability of river slope. Under the conditions considered in the present study, the water depth of the pond had little effect on the pond’s water seepage as well as the stability of the river slope. The permeability of expansive soil has a significant impact on the pond’s water seepage as well as the stability of river slope. Specifically, lower permeability coefficient of expansive soil results in lower water outflow point, lower unit width flow of leakage and higher safety factor for the river slope.