Experimental & Analytical Studies of Reservoir Compressibility Effects on Arch Dams

基于各种未经试验验证的假设，发展了预测拱坝地震反应的先进分析方法。这些数值模型在考虑了储层相互作用和水的压缩效应的同时，对储层几何形状和库底反射系数也很敏感。在该项目下，提出了一个与中国研究人员合作的研究项目：a)研究水库相互作用对拱坝的影响；b)在中国一座大型拱坝上进行现场观测，以及c)通过比较测量结果和计算结果对分析方法进行定量评估。在分析预测中需要输入的吸收储集层底部的反射系数和储集层的实际地形将通过实地调查来确定。将进行测量，以检测坝基接触面附近的水可压缩性和地面运动的空间变化。这种激励技术预计将产生更大的动水压力，并比以前使用偏心质量振动器获得的关于大坝及其地基之间的动力相互作用的信息更好。测得的大坝反应、地基反应、并将使用当前最好的数学程序将动水压力与分析预测进行比较，以验证分析技术的准确性。研究计划的最终成果将是具体的测试程序，以测量水库底部的吸收系数、测量的坝基和水库响应特性，和相关的分析预测，这将是有用的设计目的。

Advanced analytical procedures to predict earthquake response of arch dams have been developed based on various assumptions that have not been verified experimentally. While these numerical models include the reservoir interaction and the water compressibility effects, they also are sensitive to reservoir geometry and the reservoir bottom reflection coefficient. A cooperative research project with Chinese researchers is proposed under this project to: a) investigate reservoir interaction effects on arch dams, b) conduct field measurements on a large arch dam in China, and c) make quantitative evaluation of analytical procedures by comparing the measured and calculated results. The reflection coefficient of the absorptive reservoir bottom and the actual topography of the reservoir, which are required as input in analytical predictions, are to be determined by field surveys. Measurements will be made to detect water compressibility and spatial variation of ground motion near the dam- foundation contact. This excitation technique is expected to produce larger hydrodynamic pressures and better information regarding the dynamic interaction between the dam and its foundation than has been obtained previously using eccentric-mass shakers. The measured dam response, foundation response, and the hydrodynamic pressures will be compared with analytical predictions using the best current mathematical procedures to validate the accuracy of the analytical techniques. The final product of the research program will be specific testing procedures to measure absorptive coefficient of the reservoir bottom, measured dam-foundation and reservoir response behavior, and the associated analytical predictions which will be useful for design purposes.