原状滑带土压缩回弹变形的饱水软化响应

为探究滑动带在降雨、地下水位变化下进行堆载、削坡对滑带土的沉降及回弹变形的影响规律，开展了饱和度变化下原状滑带土的压缩-回弹-再压缩特性试验研究。结果表明，原状滑带土先期固结压力随饱和度的增加呈幂函数减小，其在饱和度50-60%范围内速率降低尤为明显。饱和度变化对压缩指数影响有限，而对回弹指数、回弹模量、塑性变形量及再压缩比率的影响较大，随饱和度的增加，回弹模量呈指数函数减小，塑性变形量线性增大；再压缩比率指数增长，。通过电镜扫描试验，从微观上初步揭示了饱和度变化下原状滑带土固结回弹行为的演化规律。研究成果可为降雨与地下水位变化下坡体的变形分析及稳定性评估提供基础数据。

Softening Response of the Compression and Rebound Characteristics of Undisturbed Sliding Zone Soils under Water-saturated conditions

To explore the rainfall and groundwater level fluctuation effects on settlement and rebound deformations of landslide zone soils caused by preloading and slope cutting conditions, the compression, rebound and recompression tests were done on an undisturbed landslide zone soil with varying degrees of saturation. The experimental results show that the preconsolidation pressure decreases with increasing saturations, which can be characterized using a power function. The decrease rate of the preconsolidation pressure is quite significant in the saturation range of 50-60%. The results also show the effect of degree of saturation on the compression index was limited. The resilience index, the elastic modulus, plastic deformation and recompression ratio can be affected significantly under the varying degrees of saturation conditions. Under the increasing of saturation, the elastic modulus decreases exponentially, the plastic deformation increases linearly, and recompression ratio increases exponentially. Through the scanning electron microscope technique, the mechanism for the evolution of the compression and rebound parameters under varying saturations was preliminarily uncovered in microscale. These results can provide the basis for the deformation analysis and stability assessment of slopes under rain infiltration and groundwater level fluctuation conditions.