This is of great significance in understanding the instability mechanism of bank slopes composed of different types of rocks and soils. The characteristics of Yunnan laterite soil subjected to dry-wet cycles with its influence on the stability of bank slope were studied by experimental tests. The influence of the immersion and fluctuation level of reservoir water was studied through geotechnical tests. Analytical deduction and numerical simulation were also combined in the study. Results showed that,with a fixed initial dry density,the content of clay particles in laterite first increased with the number of wet-dry cycles and then decreased before reaching to a stable value as the cycles increased. At the same time,the cohesion,internal friction angle and shear strength of laterite all decreased first nonlinearly with the increase of the cycling times,and then became stable after round 10 wetting-drying cycles. The shear strength,cohesion and internal friction angle of laterite presented a significant effect on the stability of laterite bank slope. This research could provide reference for preventing and controlling the slope failure of Yunnan lateritic reservoir bank in engineering practice.%研究干湿循环作用下云南红土特性变化对库岸边坡稳定性的影响,对深入认识不同岩土体库岸边坡失稳机理有重要意义.通过红土试样的干湿循环试验,结合土工试验、数值计算及理论分析进行研究.结果表明:1)在一定初始干密度条件下,干湿循环作用使红土的粘粒含量呈先增大后减小,然后趋于稳定的变化趋势,而粉粒含量的变化趋势则与之相反.随着干湿循环次数的增加,干密度呈先增加后趋于稳定的变化趋势.2)在一定初始干密度条件下,红土的粘聚力、内摩擦角、抗剪强度及红土型库岸的稳定安全系数均随干湿循环次数的增加而非线性减小,但在干湿循环次数约10次时趋于稳定.红土抗剪强度、粘聚力和内摩擦角对红土型库岸边坡稳定有显著影响.以上结论可为防范和治理云南红土型库岸边坡失稳提供参考.
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