以宜巴高速公路沿途彭家湾软硬岩互层边坡为工程依托，依据地质分析及相似理论建立缓倾软硬岩互层边坡室内模型，采用开挖试验及和注水软化试验来模拟实际中的工程开挖（或河谷下切）和雨水浸润软化过程，研究缓倾软硬岩互层边坡的变形破坏机制。结果表明：在开挖及雨水软化两种工况下，该类软硬岩互层边坡的变形模式都是前期的滑移拉裂变形和后期的整体蠕滑变形，破坏模式是以深部软层为滑动面的整体滑移；硬岩层与软岩层的变形情况略有不同，硬岩层以整体蠕滑变形为主，而软岩层以滑移拉裂变形为主；深部软岩层的状态变化对边坡的整体稳定性影响非常关键；工程开挖（河谷下切）及雨水入渗都会对该类缓倾软硬岩互层边坡的稳定性有重要影响，开挖导致的临空面及微裂隙是滑坡发生的基础，水是滑坡发生的条件和诱因。

A lab model experiment of low-angled slope with interbedding of soft and hard rock is designed on the basis of geological analysis and similarity theory. The lab test is based on Peng Jiawan slope at Yi-Ba highway which has interbedding of soft and hard rocks with low dip angle. In the model tests, slope excavation tests are used to simulate the engineering excavation (or valley incision); and the water injection softening processes are used to simulate the rainfall infiltration. The results show: under both excavation and rainfall infiltration conditions, the deformation modes of the slope are sliding-tension at first and overall creep-slippage in the latter; and the failure mode is overall slip failure along the sliding zone of deep soft rock. Strictly speaking, the deformation of hard rock strata differs from the deformation of soft rock strata. Hard rock deforms mainly in sliding-tension but soft rock deforms mainly in overall creep-slippage. Changes of the condition of deep soft rock affect the total stability of the interbedding slope mostly. Both excavation and rainfall infiltration would lead to decline of stability of the slope. The free surfaces and micro-fissures induced by excavation are the basis triggering slope failure, and the rainfall provides incentives to the slope failure .