面板堆石坝地震响应的离心机振动台模型试验研究

Due to the development of hydropower resources in Western China, a large number of high concrete-faced rock-fill dams have been built in high seismic region, and many are planned to be built in such area in the future. Since the safety of dams is related to the life and property safety of people in the downstream area and the national economic development, it is very important to examine the seismic behavior of concrete-faced rock-fill dams. A series of dynamic centrifuge tests on dams before and after impoundment are planned to be carried out in this research using the horizontal-vertical centrifuge shaker. The variation in the dynamic properties in rock-fill due to shaking will be examined using a bender element system, and the stress and deformation redistribution in the dam due to creep after shaking will be explored. Based on the study, how previous shaking influence the seismic behavior can be understood. The distribution of dynamic water pressure on the face and its variation due to shaking will be measured using tactile pressure sensors, and how the dynamic water pressure affect the deformation of dams and the face stress and strain will be discussed. The seismic behavior of dams subjected to horizontal-vertical shaking, before and after impoundment, will be further examined. The seismic behavior is in terms of acceleration response, dam deformation, the stresses in the face and the dynamic water pressure. The research findings are useful for the seismic design and the optimization of seismic measure of concrete-faced rock-fill dams.

随着西部水电资源的开发，我国有相当数量的高面板堆石坝建于强震区，并有一批拟建的强震区高面板堆石坝。由于坝体安全关系到下游广大人民生命财产安全和国民经济发展，深入研究面板堆石坝地震响应的重要性和迫切性越来越突出。基于双向离心机振动台试验技术，本项目拟针对竣工期、蓄水期面板堆石坝开展一系列模型试验。采用基于压电弯曲元的剪切波速测量系统探究地震作用下堆石体动力特性变化规律，揭示震后蠕变期面板堆石坝应力变形重分布模式，进而提出先期地震动影响坝体地震响应的内在机制；采用薄膜压力传感器，探究地震过程中动水压力的分布及变化规律，揭示动水压力对面板堆石坝堆石体变形、面板应力应变的作用机制；探究顺河向、竖向双向地震动作用下竣工期、蓄水期面板堆石坝的地震响应，包括加速度反应、坝体变形、面板应力、动水压力等内容。研究成果将为面板堆石坝的抗震设计和抗震加固措施优化提供理论基础和技术支撑。

随着西部水电资源的开发，我国有相当数量的高面板堆石坝建于强震区，并有一批拟建的强震区高面板堆石坝。由于坝体安全关系到下游广大人民生命财产安全和国民经济发展，深入研究面板堆石坝地震响应的重要性和迫切性越来越突出。基于双向离心机振动台试验技术，本项目针对竣工期、蓄水期面板堆石坝开展了一系列模型试验，揭示了地震作用下堆石体动力特性变化规律，揭示了先期地震动对坝体地震响应的影响规律，获得了地震作用下坝体偏应变分布、位移场及剪应力-剪应变滞回曲线等关键数据；综合采用地面振动台模型试验及离心机振动台模型试验相似理论，对200m级蓄水期面板坝进行了离心机振动台模型试验，得到了地震作用下坝面水压力变化规律及动水压力沿高程的分布规律，揭示了面板应力变形规律；探究了顺河向、竖向双向地震动作用下竣工期、蓄水期面板堆石坝的地震响应，包括加速度反应、坝体变形、面板应力应变、动水压力等内容。研究成果将为面板堆石坝的抗震设计和抗震加固措施优化提供理论基础和技术支撑。