水下岩质边坡稳定性的模型试验研究

随着三峡水利建设工程的进行，许多原本位于水面以上且已趋于稳定的人工或自然岩质边坡将被淹没，导致边坡稳定性降低，而水的压力、冲击、渗流和侵蚀等综合作用，给下岩质边坡的稳定性带来大量的不确定性。基于已有的水下土质边坡稳定性试验和水下岩质边坡有限元分析，进行水下岩质边坡模型试验研究，探讨在水位升降水过程中和波浪作用下水下岩质边坡的稳定性和破坏机制。将结构面为30°和50°的两种岩质边坡模型布置在人工水槽中，采用波流系统进行水位升降水波浪冲击试验，量测岩质边坡的应力变化。通过分析边坡各测点应力变化，得出了一些有意义的结论：（1）把边坡前部岩体划分成3个区域，每个区域内应力变化规律相同；（2）水下岩质边坡坡脚处应力集中最大，破坏始于坡脚，并由此产生的塑性区沿结构面逐渐同坡顶发展，这与一般边坡从坡顶逐渐向下发展的开裂破坏形式完全不同；（3）波浪对水下岩质边坡结构面的影响，将随其倾角的变小而减弱。

Model test on stability of underwater rock slopes

With the construction of the Three Gorges Project, many natural and artificial rock slopes will be drown, then the stability of these slopes will reduce. The comprehensive factors of the water pressure, water leakage, water impaction and water corrosion will endanger the stability of underwater rock slope. Based on the model tests of the stability of soil slope and the analysis of the rock slope by the finite element method, the model tests of stability and damage mechanism of underwater rock slope are carried out, including the ascending and descending water level test and the wave impaction test. Some significant conclusions can be drawn from the model tests by measuring and analyzing the stress distributions with different structural angles (30° and 50°) slopes in the artificial wave tank. The rock slope can be divided into three regions in which the stress variation rule is the same. The results show that the stress concentration occurs to the slope toe, where failure begins, plastic zone develops upwards along the discontinuity, which is different from the downward failure mode happened to general slopes; it’s also concluded that the effect of the wave on the slope discontinuity decreases with the slope angle.