基于NB35047-2015规范的锦屏拱坝抗震复核

能源行业标准《水电工程水工建筑物抗震设计规范》(NB35047-2015)已于2015年9月1日颁布实施。介绍了依据该规范开展的锦屏一级高拱坝抗震安全复核工作。主要内容包括:基于设定地震的场地相关设计反应谱研究;采用动力拱梁分载法、线弹性有限元法和非线性有限元法,进行设计和最大可信地震作用下的应力和坝肩岩体动力稳定分析;在选定的人工地震波基础上,采用以基岩峰值加速度在设计地震基础上比例放大的方式,进行大坝地基系统在超设计地震荷载下的地震超载能力分析。复核分析表明,锦屏一级高拱坝具有较高的抗震潜力;设计地震和最大可信地震作用下,坝体抗压强度安全满足现行抗震规范要求,且抗压强度安全有较大安全裕度,坝体拉应力基本未超过混凝土容许的应力范围,仅局部应力集中部位拉应力较大,能满足校核地震作用下"不溃坝"的设防要求。

Anti-seismic check of arch dam of Jinping I Hydropower Station based on new standard of NB35047-2015

National energy industry standard, NB35047-2015, was released on September 1, 2015. The anti-seismic safety of Jinping I arch dam was reviewed based on this new code and the main check works includes: study on site design response spectrum based on the determined earthquake scenario; stress and dam abutment dynamic stability analysis under design earth-quake and maximum credible earthquake by using arch-cantilever method, linear elastic FEM and nonlinear FEM;based on the selected artificial earthquake wave, and by proportionally amplifying the peak ground acceleration on the basis of design earth-quake, the overload capacity analysis of dam-foundation system under excess design earthquake. The check result shows that the arch dam of Jinping I Hydropower Station has high anti-seismic capability. Under the design and maximum credible earth-quakes, the compressive strength meets the current code requirement with a larger security margin. The tensile stress is generally under the concrete control value except that of some stress concentrated area comparatively. The dam will not collapse under the check earthquake level.