北疆地区砾石土岸坡冲刷破坏大比尺模型试验及其破坏机理研究

以北疆地区广泛存在的砾石土重建岸坡,开展砾石土岸坡冲刷破坏大比尺模型试验研究。引入新型观测方法——三维激光扫描技术,对岸坡冲刷破坏全过程进行观测,并详细分析获取的扫描数据。联合三维激光扫描和现场传统测量成果,依据不同阶段的破坏特征,将岸坡破坏划分为3个阶段,即冲刷破坏阶段、局部失稳阶段和整体失稳阶段,确定北疆地区砾石土岸坡的冲刷变形失稳过程与破坏模式。基于砾石土岸坡大比尺模型试验成果,推导建立砾石土岸坡稳定性计算公式和局部失稳破坏高度预测公式,并建立砾石土岸坡冲刷破坏阶段和局部失稳阶段的有机联系,以深入揭示砾石土岸坡失稳破坏机理。

Large scale model tests on scour failure of gravelly soil bank slope in northern area of Xinjiang and its failure mechanism

The gravelly soil widespread in norther area of Xinjiang is chosen to reconstruct bank slope. Large scale model tests on hydraulic scour of gravelly soil bank slope are carried out. A new observation method, three-dimensional laser scanning technique, is introduced to observe erosion damage of the bank slope. Based on the results of 3D laser scanning and traditional measurement methods, according to the failure characteristics at different stages, the failure of the bank slope is divided into three stages, namely scour damage stage, local instability stage and overall instability stage. The instability process of deformation and the failure mode of the gravelly soil bank slope are determined. Based on the test results, the formulae for calculating the stability and predicting the local buckling failure height are derived. Through this study, the relation between the scour damage phase and the local buckling stage is established, and the failure mechanism of typical gravelly soil bank slope is deeply revealed.