Experimental Research on Interactions of Impounded-Water and Foundation-Rock with Arch Dams

本研究项目将重点对中国另一座大型拱坝进行详细的现场实测和响应预测分析，研究蓄水、泥沙和基岩与大坝的动力相互作用机制。新的研究领域包括水坝-水-沉积物相互作用对沉积物性质和沉积物厚度的影响，峡谷地形对自由场地面运动的影响，以及改进的动力激励技术。现场测量的基本概念是通过爆轰装药来激发大坝及其积水的动力响应。将采用两种类型的爆炸试验：应用于基岩的爆炸试验和在湖水中引爆的爆炸试验。此外，还将采用地震反射和折射两种方法测量湖底材料的反射系数。所提出的试验方案将使人们更好地了解拱坝在与蓄水和基岩相互作用下的实际动力响应行为；通过湖底材料的能量吸收；受湖泊地形影响；以及峡谷周围地面运动的空间变化。所提出的研究结果将有助于更好地了解大坝-水-泥沙和大坝-基础的相互作用效应，并将提供测量数据，通过这些数据可以检验和可能提高分析拱坝地震反应的计算机程序的准确性。

This research project will focus on detailed field measurements and response prediction analyses of another large arch dam in China, to study dynamic interaction mechanisms of the impounded-water, sediment, and foundation rock with the dam. New areas of investigation include the dam-water-sediment interaction effects with respect to the sediment properties and sediment thickness, effects of canyon topography on the free-field ground motions, and improved dynamic excitation techniques. The basic concept in the field measurements is to excite the dynamic response of the dam and its retained water by detonating explosive charges. Two types of explosion tests will be employed: those applied to the foundation rock and those detonated in the lake water. In addition, two approaches based on the seismic reflection and refraction techniques will be employed to measure the reflection coefficient of the lake-bottom materials. The proposed test program will provide improved understanding of the actual dynamic response behavior of arch dams influenced by the interaction with the impounded-water and the foundation rock; by the energy absorption of the lake-bottom materials; by the lake topography; and by the spatial variations of ground motion around the canyon. Results of the proposed research should lead to better understanding of the dam-water-sediment and dam-foundation interaction effects, and will provide measured data by which the accuracy of computer programs for analyzing the earthquake response of arch dams can be examined and possibly improved.