土石坝动力离心模型试验颗粒流数值模拟

PFC numerical simulation for dynamic centrifugal model tests on earth-rockfill dams

以长河坝离心模型试验为基础,开展颗粒流细观数值模拟研究,分析大坝在不同地震加速度和离心加速度下的动力响应(加速度和位移)和破坏模式,并对长河坝双向振动台模型试验进行了数值模拟分析.数值模拟结果表明:数值模拟规律与离心振动台试验规律基本一致,坝体的地震破坏模式为坝顶局部滑动破坏;同一高程坝坡位置的动力响应大于心墙位置;随着地震加速度峰值的增大,坝体加速度放大系数减小,坝体破坏模式不变;随着离心加速度的增大,坝体加速度放大系数减小,坝顶沉降减小.

The meso-mechanical simulation was performed based on the dynamic centrifugal model tests on Changhe Dam.The dynamic response（acceleration and displacement） and failure modes of Changhe Dam under different earthquakes and centrifugal accelerations were analyzed.The bi-axial shaking table model tests on Changhe Dam were also simulated and analyzed.The simulated results show that the numerical simulations agree with the results of the dynamic centrifugal model tests.The failure mode of dam body caused by earthquakes is the local sliding failure at the dam crest.The response on the dam slope at the same height is larger than that on the core wall.With the increase of the peak value of earthquake acceleration,the magnification coefficient of acceleration decreases,and the failure mode of dam body remains unchanged.With the increase of the centrifugal acceleration,the magnification coefficient of acceleration also decreases,and the settlement of dam crest decreases.