典型冰水堆积体浪蚀作用下变形破坏机制研究

DEFORMATION AND FAILURE MECHANISM OF AN OUTWASH DEPOSIT UNDER SCOURING OF RIVER WATER

大渡河中游沿岸中海拔地区广泛分布的一层冰水堆积体大多具有较为密实的结构和一定程度的胶结,在风浪作用下的变形破坏机制与其他堆积体存在较大差别。通过对某电站库区高速公路冰水堆积路基岸坡调查和试验分析认为,该冰水堆积体属级配良好的含细颗粒的粗粒~巨粒混合土,颗粒之间嵌合紧密,一般呈中密~密实状,具有不同程度的泥质、钙质胶结,其强度明显较其他松散堆积体高。通过采用地质过程定性分析和有限元半定量评价相结合的手段对该冰水堆积体在风浪作用下的变形破坏机制进行了分析和研究,认为该类冰水堆积体在风浪作用下主要表现为淘蚀-坍塌型失稳模式。

There are many outwash deposits distributed in the middle - elevation area of the middle reaches of the Dadu river. Owing to the dense structure of the outwash deposits, and the detritus is cemented in some degrees sometimes. So the deformation and failure mechanism of the outwash deposits under scouring of fiver water flow are different from those of other deposits. This paper investigates the outwash deposits on a reservoir bank and tests them. A conclusion is obtained that the outwash deposits should be classified as mixture soil with coarse granule and giant granule. The granules were tabled densely, and the outwash deposit intensity is higher than other deposits. Based on the findings, a detailed study is given on the deformation and failure mechanism of the outwash deposits under action of river water flow by the means of geological process analysis and numerical simulation analysis. It is figured out that the outwash deposits should be failed like eroding - collapsing under river water action.