随机波浪作用下饱和砂质海床弹塑性动力响应规律

采用振动台试验研究了饱和砂土地基(CSS)和EPS混合土地基(CES)两种地基模型下沉箱结构的抗震性能。对比了两种不同地基模型下土体动力响应特征及沉箱结构动力稳定性，探讨了动力作用下沉箱的受力状态及失稳机制，分析了EPS混合土地基对上部沉箱结构地震稳定性的影响。试验结果表明：振动过程中CES工况的超孔压发展速率明显低于CSS，EPS混合土可显著提高模型抗液化性能。墙后填土作用于沉箱的动土压力沿深度方向呈三角形分布，沉箱中部位置动土压力最大。CES工况沉箱动力响应，包括加速度、位移及转动角等均小于CSS，表现出更好的抗震性能。CES沉箱所受动土推力与惯性力存在明显的相位差，有利于提高沉箱结构的稳定性。

Performance of caisson type quay walls at Kobe port

A series of shaking table tests are conducted to study the seismic performance of caisson structure under saturated sand foundation (CSS) and EPS composite soil foundation (CES). The dynamic response characteristics of soil and the dynamic stability of caisson structure are analyzed. The force state and instability mechanism of caisson under dynamic loading are discussed. The influence of CES on seismic stability of the upper caisson structure is discussed. The experimental results indicate that the development rate of excess pore pressure under CES conditions is significantly lower than that under CSS, and EPS composite soil can significantly improve the liquefaction resistance. The dynamic earth pressure acting on the caisson is triangular along the depth direction, and it is the largest at the middle of the caisson. The dynamic response of the caisson under CES conditions, including acceleration, displacement and rotation angle, is smaller than that under CSS conditions, which shows better seismic performance. There is an obvious phase difference between the dynamic earth thrust and inertia force of CES caisson, which is conducive to improving the stability of caisson structure.