考虑干湿循环的膨胀土航道边坡稳定分析及治理措施

Swelling soil slope stabilization analysis and treatment measures considering wet and dry cycles in navigation project

针对航道边坡土体为膨胀土时极易产生季节性、浅层性滑动,影响航运能力及工程安全的问题,依托芜申航道南京段失稳边坡处治工程,对膨胀土进行往复干湿循环后的直剪试验和考虑干湿循环效应的稳定性分析。结果表明:随干湿循环次数的增加,膨胀土的黏聚力、内摩擦角逐渐衰减,其衰减主要发生在前3次干湿循环过程中,之后趋于稳定;黏聚力的衰减程度远大于内摩擦角;考虑干湿循环效应引起的土体强度衰减,是获得膨胀土边坡真实稳定系数的正确计算方法。针对失稳边坡提出采用门字形抗滑桩的处治措施,应用效果良好,具有较好的工程借鉴意义。

Regarding the problem of seasonal and shallow sliding when the slope of the navigation channel is swelling soil,which affects the shipping capacity and engineering safety,we carry out the straight shear test of swelling soil after reciprocal wet and dry cycles and the stability analysis considering the effect of wet and dry cycles based on the treatment project for the destabilized slope of Nanjing section of the Wu-Shen Navigation Channel.The results show that the cohesion and internal friction angle of swelling soil decay gradually with the increase of the number of wet and dry cycles,and the decay mainly occurs in the first three dry and wet cycles,and then gradually stabilizes.The decay degree of cohesion is much larger than that of internal friction angle.Considering the soil strength decay caused by the wet and dry cycle effect is the correct calculation method to obtain the true stability coefficient of swelling soil slopes.The treatment measure of using gate-shaped anti-slip piles is proposed for the unstable slope,and has good application effect and engineering reference significance.