平缓反倾红层边坡变形破坏机制研究

Deformation and Failure Mechanism of Gently Anti-inclined Red-bed Slope

以赤水市旺隆边坡为工程实例,依据野外调查和地质分析成果建立平缓反倾红层边坡概念模型,并结合离散元数值模拟研究贵州平缓反倾红层边坡的变形破坏机制。结果表明:旺隆边坡是砂泥岩不等厚互层的典型平缓反倾红层边坡,差异风化和降雨是主要的诱发因素。边坡的变形演化过程经历4个阶段:卸荷回弹、浅表生改造-局部变形、裂隙扩展延伸、裂隙贯通深部蠕滑。变形破坏机制根据不同变形阶段划分为3种不同形式:压缩-拉裂-倾倒、风化剥落-坠落、蠕滑-压致拉裂。

An engineering example of Wanglong slope with gently anti-inclined red bed was studied.A conceptual model was first established based on the results of field investigation and geological analysis. Then the deformation and failure mechanism of gently anti-inclined red-bed slope in Guizhou was discussed through discrete element numerical simulation.The results show that Wanglong slope in Chishui City is a typical red-bed slope in Guizhou province with gently anti-inclined bedding and interbedded sand and mudstone of unequal thickness.Differential weathering and rainfall are the two important inducing factors for slope failure.The deformation process of the slope undergoes four stages,that is,unloading rebound,shallow epigenetic transformation and local deformation,fracture extension and propagation, fracture coalescence and deep creeping.The deformation and failure mechanism are divided into three different forms according to deformation stages:compression-cracking and dumping,weathering-spalling and falling,creeping-compression cracking.