高拱坝抗震安全性能评价指标探讨  

Discussion on evaluation index of seismic safety performance of high arch dams

作　　者：李静 陈健云 徐强 LI Jing;CHEN Jianyun;XU Qiang(Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116023,China)

机构地区：[1]大连理工大学建设工程学部

出　　处：《人民长江》2019年第9期129-136,共8页Yangtze River

基　　金：国家自然科学基金资助项目(51679030);国家重点研发计划项目(2017YFC0404900)

摘　　要：随着拱坝建设高度和设防烈度的不断提高,传统的强度评价指标已无法满足抗震安全评价的需求。针对300m级高拱坝的抗震安全评估,建立了考虑坝体横缝接触非线性、坝体混凝土材料非线性以及坝基岩体断层、夹层非线性的有限元模型,采用地震动逐级加载,分析了拱坝的横缝开度、坝顶变形以及坝体损伤随着地震动强度的变化规律。分析表明:尽管在地震动强度很大的情况下坝体中上部损伤程度很大,但坝顶位移、横缝张开度等响应随地震动强度的变化并没有表现出明显的突变现象,并不适宜作为坝体抗震安全的评定指标和监测指标;相比而言,坝体损伤体积的变化随着地震动强度的增加出现突变,反映了坝体整体的破坏状态,可以作为拱坝抗震安全的评价指标;今后需要解决坝体变形、横缝开度等与坝体、坝基损伤之间的相关性关系。With the continuous increase of arch dam height and fortification intensity,the traditional strength evaluation index can not meet the needs of seismic safety evaluation.In this paper,a finite element model is established to do the seismic safety assessment of 300 m high arch dams.The model takes the contact nonlinearity of transversal joints into account,the nonlinearity of concrete material of the dam body and nonliner effects of rock foundation fault.The variation of opening of the transversal joints,deformation of arch crest and damage ratio of dam body with seismic strength are analyzed by incremental dynamic analysis method.The results show that there are no marked change for the variation of the displacement of arch crest and the opening degree of horizontal joint with the seismic intensity though the upper part of the dam is damaged severely under strong earthquake.The displacement of arch crest and transversal joint opening are not suitable to be evaluation index and monitoring index of seismic safety of dam body.In contrast,the variation of the damage volume fraction of the dam body with the increase of seismic intensity appears to change abruptly,which reflects the overall damage state of the dam body and can be used as an evaluation index of the seismic safety of the arch dam.It is necessary to explore the relationship between the dam body deformation,transversal opening etc.and the damage of dam body and dam foundation in the future.

关 键 词：抗震安全性能 高拱坝 坝体损伤体积 评价指标 地震 

分 类 号：TV642.4[水利工程—水利水电工程]