采用原状膨胀岩进行室内边坡模型试验,研究膨胀岩边坡在连续降雨和湿-干循环模式下的变形和水分入渗特性,揭示两种模式下膨胀岩边坡的变形破坏模式。试验发现,连续降雨模式下初期数次降雨对膨胀岩边坡变形影响最大,有明显的水平方向位移,后期变形很小且趋向稳定。湿-干循环模式下边坡膨胀变形及深部岩体含水率降雨完成后一段时间才达到峰值,随循环次数及降雨量增大,边坡变形速率及变形量都明显增大,岩体裂隙不断发育,水分入渗深度增大,但限于表面一定深度,对深部岩体影响较小。试验结果对工程应用有一定的指导意义:连续降雨模式初期膨胀较大,须加强和完善初期的排水措施,做好边坡的支挡防护措施;湿-干循环模式下,随循环次数增加,做好坡面的防护措施,以起到保湿防渗作用;两种降雨模式均说明纯膨胀性泥岩边坡不发生典型的圆弧滑动等破坏模式,而工程边坡的滑动多发生在软弱夹层上,因此,要做好该类边坡的软弱夹层特性勘察,对于不含软弱夹层的纯泥岩边坡要重点监测其浅层变形特性。 The original slope expansion model was used to study the deformation and infiltration characteristics of the expansive rock slope under continuous rainfall and wet-dry cycles. The deformation and failure modes of the expansive rock slope under the two modes were revealed. It is found that the initial rains in the continuous rainfall mode have the greatest influence on the deformation of the swelling rock slope with significant horizontal displacement. The deformation in the later stage is small and tends to be stable. In the wet-dry cycle mode, the deformation of the slope and the moisture content of the deep rock mass peaked after a certain period of time. With the increase of the number of cycles and rainfall, the deformation rate and the deformation of the slope increased obviously, and the fractures of the rock mass continuously developed , Water infiltration depth increases, but limited to a certain depth of the surface, less impact on the deep rock mass. The experimental results have certain guiding significance for the engineering application. In the early stage of continuous rainfall mode, the initial expansion should be strengthened and perfected. The initial drainage measures should be strengthened and the slope support measures should be taken. In the wet-dry circulation mode, The protective measures on the slope are to be taken to protect the seepage from moisture. Both rainfall patterns indicate that no typical failure modes such as circular arc slip occur in the pure expansive mudstone slope. However, the slip of the engineering slope occurs in the weak interlayer Therefore, to investigate the weak interlayer characteristics of this type of slope, the shallow deformation characteristics of the pure mudstone slope without soft interlayer should be monitored.