中文摘要：

发育于花岗岩出露区的典型崩岗岩土受干湿效应影响，致使坡体在重力作用下产生崩坍，这是崩岗形成后最主要的侵蚀形式。通过对原状土进行5种干湿水平处理，采用直剪试验研究干湿效应下崩岗岩土抗剪强度及其指标变化规律。结果显示：从风干到增湿过程，抗剪强度及其指标衰减明显，粘聚力C下降幅度最大为92％，而内摩擦角9最大降幅为48％。随着垂直压力递增，抗剪强度增大。此外，基于不同干湿效应下岩土抗剪强度指标变化规律，运用模糊综合评判法对不同干湿水平、干湿阶段崩岗坡体稳定性等级（重力侵蚀）进行评价，并讨论了完善该模型的途径，可为崩岗危害性分级、针对性治理提供技术支撑。

英文摘要：

The typical collapsed drying rock soils derived from granite effect that causes collapse under the influence of gravity outcropped area is significantly affected by the wetting due to shear strength decrease. It is the major erosion form of slope disintegration. Direct shear strength tests with five wetting and drying treatments were conducted to iden- tify effect of wetting - drying on shear strength and indices change rules of the slope disintegration. The results show as wetting - drying levels increased, the shear strength and indices decreased obviously. The maximum decline ex- tent in cohesion c was 92%, and in internal friction angle ~ was 48%. While, shear strength increased with vertical loads. A fuzzy synthetic evaluation was performed for the evaluation of the slope disintegration stability （ gravitational e- rosion） based on shear strength indices under wetting -drying levels and stages. It was discussed the improvement methods of the assessment model that would classify the harmfulness degrees of the slope disintegration and provide the technical support for erosion control.