重力坝动力特性测试方法模型试验研究

Model testing method for dynamic properties of gravity dam

目前水工结构的动力破坏特性越来越受到关注,其中动力特性是其研究的一个重要方面。通过模型试验的方法研究重力坝模型动力特性的测试方法。重点研究了环境激励法测试结构动力特性的效果,并与传统测力法进行了比较。试验结果表明采用环境激励的方法,可只根据结构的振动响应数据,有效地测试结构的动力特性。并且在不同大小环境激励下结构的振型没有发生变化,频率与阻尼比变化很小。试验结果还表明通过环境激励法与通过传统激励法测试的振型、频率与阻尼比相差很小,可认为采用这两种方法测试的结构动力特性一致。同时还说明环境激励法可有效地测试有损伤结构的动力特性。试验结果为使用环境激励法测试实际在线重力坝结构的动力特性提供了依据。

The ambient vibration testing method for detecting dynamic properties of a gravity dam model was studied and the results were compared with those by using traditional testing method. The experimental results show that ambient vibration testing method can measure the structural dynamic properties effectively by merely using structural dynamic responses. The mode shapes, frequencies and damping ratios of model structure were affected lightly by the magnitude of ambient excitation. The testing results of dynamic properties of model structure by ambient vibration testing method are in good agreement with those by traditional testing method. The results also show that ambient vibration testing method can detect the dynamic properties of damaged structures validly as well and can also be used in site tests.