两河口高土石坝动力特性振动台模型试验研究

Study on shaking table model tests for dynamic characteristic analysis of the Lianghekou High Rock-Fill Dam

土石坝坝体自身的动力特性,是土石坝在地震动作用下动力响应性状的重要影响因素。本文通过大型振动台模型试验,研究了两河口高土石坝缩尺模型坝的动力特性及其相关影响规律,并根据相似率,用模型坝的动力特性参数推算出原型高土石坝的相应动力特性参数。试验研究表明:在特定的地震动作用下,大坝结构的振型基本稳定;坝体的自振频率、阻尼比和振型系数等动力特性参数受振动强度、振动历史和水库是否蓄水等因素影响。

Dynamic response characteristics of high rock-fill dams subjected to earthquake are greatly affected by their own dynamic characteristics. In this study, firstly, the dynamic characteristics and coherent reg- ularity of the model for Lianghekou dam with height 295m, were obtained through shaking table model tests, and then the corresponding dynamic characteristics of prototype high rock-fill dam were obtained by the test results according to the similarity rules. The main conclusions include： basically the dam has a sta- ble vibration mode under special seismic vibration; dynamic characteristics of the dam are affected by many factors, such as the vibration intensity, vibration history, reservoir impounding, and so on.