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本文在通过对新丰江和柯依那(Koyna)大坝的震害情况进一步分析,和选择了其它一些重力坝进行研究后,提出了岩基上重力坝抗震设计地震系数的采用及安全性估算的意见. 在重力坝的抗震设计中,按照静力法或拟静力法和经验的地震系数、抗剪强度的静力指标检验大坝的抗滑稳定性,是可以得到基本估计的,但还存在某些问题;尤其是,在进行坝体强度校核时,往往会使人产生误解.因此,作者认为有必要采用动力分析法和预计的设计坝基地震系数,以估算地震荷载和应力,并与正常荷载的情况组合,取强度的静力指标作出比较,才能得到近乎合理的安全估算. 文中着重研究了大坝滑动稳定性问题,提出了抗震的稳定相对安全率的概念,它有助于揭示地震时大坝抗滑稳定的变化规律,并作出安全的估算. 在分析时,将坝体和库水作为有限单元的集合体,考虑了坝体与库水在振动时耦合作用,按反应谱法和时程法进行动力分析,得出了动力和静力的综合成果.
Based on the further analysis of the seismic damage of the Xinfengjiang and Koyna dams and the selection of other gravity dams, this paper presents the adoption and safety of earthquake-resistant seismic design of gravity dams on rock foundations Estimated opinion: In the anti-seismic design of gravity dam, it is possible to get a basic estimate of the anti-sliding stability of the dam according to the static method or quasi-static method and the empirical seismic coefficient and the static index of shear strength. However, some problems still exist, and in particular, it is often misleading to check the strength of the dam, so the authors consider it necessary to use dynamic analysis and estimated dam foundation seismic coefficients to estimate the seismic load and stress , And combined with the normal load conditions, take the static strength of the indicators to make a comparison, in order to get a nearly reasonable safety estimates.This paper focuses on the dam sliding stability issues, put forward the concept of seismic stability of the relative safety rate, it has Which can help to reveal the variation law of the anti-sliding stability of the dam during the earthquake and make a safe estimation.In the analysis, the dam body and the reservoir water are taken as the aggregate of the finite elements, When coupling, dynamic analysis carried out by the response spectrum method and time history method, come to power and consolidated results of static.