摘要
结合金沙江上游拉哇特高混凝土面板堆石坝,分别采用黏弹性模型的等效线性方法和基于静动力弹塑性模型的耦合方法,在相同加速度时程下对比分析两种动力方法计算得到的坝体和面板加速度反应、震后永久变形等特征,从而探讨两者动力反应性状的差异。结果表明,采用河海统一广义塑性模型计算得到的坝顶加速度放大倍数略低于黏弹性方法,从总体上看坝体加速度放大效应基本一致;从震后永久变形的计算结果来看,由于黏弹性方法不能直接计算永久变形,将土体的滞回性用等效黏性代替,远小于统一广义塑性模型的计算值;两种方法计算得到的面板应力分布规律基本一致,但由于更大的永久变形导致弹塑性耦合方法的计算应力明显高于等效线性方法的结果。总体而言,基于静动力弹塑性模型耦合方法的动力反应计算结果更偏于安全,对于高坝或强震区土石坝而言,需采用弹塑性静动力耦合方法进行抗震分析。研究结论可为类似工程提供参考。
Combined with Lawa super high concrete face rockfill dam in Jinshajiang River, the equivalent linear method of viscoelastic model and the coupling method based on static and dynamic elastoplastic model are adopted respectively to compare the acceleration response and permanent deformation of the dam and face plate under the same acceleration time history. The differences of dynamic response characteristics are discussed. The results show that the acceleration amplification coefficient calculated by the unified generalized plastic model of Hohai University is slightly lower than that calculated by the viscoelastic method, and the acceleration amplification effect of the dam is basically the same on the whole. From the results of calculating the post-earthquake permanent deformation, since the viscoelastic method can’t directly calculate the permanent deformation, the hysteresis of soil is replaced by equivalent viscosity, which is far less than the calculated value of the unified generalized plastic model. The distribution law of face plate stress calculated by the two methods is basically the same, but the stress calculated by the elastic-plastic coupling method is obviously higher than that of the equivalent linear method due to the larger permanent deformation. Generally speaking, the dynamic response calculation results based on the coupling method of static and dynamic elasto-plastic model are safer. For high dams or dams in strong earthquake areas, the elasto-plastic static and dynamic coupling method is needed for seismic analysis. The research conclusion can be a reference for similar projects.
作者
王晓亮
朱家奇
苏军安
王庆祥
WANG Xiao-liang;ZHU Jia-qi;SU Jun-an;WANG Qing-xiang(Power China Zhongnan Engineering Corporation Limited,Changsha 410014,China;College of Hydrology and Hydropower Engineering,Hohai University,Nanjing 210098,China)
出处
《水电能源科学》
北大核心
2022年第10期95-99,共5页
Water Resources and Power
关键词
面板堆石坝
本构模型
地震反应分析
永久变形
有限元
CFRD
constitutive model
seismic response analysis
permanent deformation
finite element
