基于黏弹性边界的重力坝动力损伤特性分析  

Analysis of Dynamic Damage Characteristics of Gravity Dams Based on Viscoelastic Boundary

作　　者：方勇 徐苏 余代广 田菊飞 FANG Yong;XU Su;YU Dai-guang;TIAN Ju-fei(Nanjing Water Conservancy Planning and Design Institute Co.Ltd.,Nanjing 210000,China;Northwest Engineering Corporation Limited,Xi’an 710065,China)

机构地区：[1]南京市水利规划设计院股份有限公司,南京210000 [2]西北勘测设计研究院有限公司,西安710065

出　　处：《水利科技与经济》2024年第5期1-6,共6页Water Conservancy Science and Technology and Economy

基　　金：国家重点研发计划课题(2018YFC1508603)。

摘　　要：重力坝-地基的动力相互作用机理十分复杂,其中地震动的输入对重力坝的动力响应影响尤为重要。由于传统的无质量地基无法体现地基质量的惯性作用和地震波在截断边界处的逸散效果,并不能真实模拟出地震作用下的重力坝动力响应。通过在地基截断边界处设置黏弹性边界,可以很好模拟地震波向远域地基逸散的效果,将采用无质量地基时的封闭地基系统转换成与真实情况更为契合的开放地基系统。为了更真实模拟出Koyna重力坝的动力反应,基于损伤力学理论,建立Koyna重力坝动力损伤模型,通过在地基截断边界处设置黏弹性边界,模拟Koyna地震波在地基中的传输过程,从坝体损伤分布、位移及耗能情况三方面分析Koyna重力坝在地震作用下的动力损伤特性。结果表明,黏弹性边界能真实模拟出远域地基辐射阻尼现象,既能吸收传输到边界处的散射波能量,又具有良好的计算稳定性,采用黏弹性边界及损伤力学能很好模拟出重力坝在地震作用下的损伤特性。The dynamic interaction between gravity dams and foundations is a very complex research topic,in which the input of seismic motion has a particularly important impact on the dynamic response of gravity dams.Due to the traditional massless foundation being unable to reflect the inertial effect of foundation mass and the dissipation effect of seismic waves at the cutoff boundary,it is not possible to truly simulate the dynamic response of gravity dams.By setting viscoelastic boundaries at the cutoff boundary of the foundation,the effect of seismic wave dissipation towards the far-field foundation can be well simulated,transforming the closed foundation system using massless foundation into an open foundation system in real situations.This article aims to simulate the dynamic response of the koyna gravity dam more realistically.A dynamic damage model for Koyna gravity dam was established based on the theory of damage mechanics.The transmission process of Koyna seismic waves in the foundation was simulated by setting a viscoelastic boundary at the cutoff boundary of the foundation.The dynamic damage characteristics of Koyna gravity dam under earthquake are analyzed from three aspects:damage distribution,displacement and energy dissipation.The results show that the viscoelastic boundary can truly simulate the radiation damping phenomenon of the far-field foundation,absorb the scattered wave energy transmitted to the boundary,and have good computational stability.The use of viscoelastic boundary and damage mechanics can effectively simulate the damage characteristics of gravity dams under earthquake action.

关 键 词：重力坝 黏弹性边界 地震动 损伤特性 

分 类 号：TV641[水利工程—水利水电工程]