Abstract
We have conducted research on non-linear analysis for concrete dams using the smeared crack model. Efforts to verify applicability and accuracy of such numerical analyses for concrete dams have been made through simulations for actual damages of existing concrete dams due to large earthquakes. But, a more quantitative evaluation of the cracking process of concrete dams using crack analysis is needed in order to use such analytical method to estimate the limit state of concrete dams against large earthquakes. In the present study, we conducted shaking table tests on pillar-shaped unreinforced concrete specimens to investigate the effect of cracks on the dynamic behavior of concrete structures. The results showed that as tensile fracture progresses, the first resonant frequency of the specimen lowers and the damping increases. We simulated vibration tests by non-linear dynamic analysis based on the smeared crack model. Based on a comparison of the test results and numerical simulation, we discuss how to set parameters for numerical simulation such as the tension softening curve and damping ratio, to simulate the cracking behavior of unreinforced concrete structures such as concrete dams.
