基于改进云图法的高土石坝抗震可靠度分析  

Seismic reliability analysis of high earth-rock fill dams based on an improved cloud method

作　　者：靳聪聪 迟世春 李士杰[3] 聂章博 JIN Congcong;CHI Shichun;LI Shijie;NIE Zhangbo(Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China;Kunming Engineering Corporation Limited of Power China,Kunming 650051,China)

机构地区：[1]大连理工大学建设工程学部,大连116024 [2]大连理工大学海岸与近海工程国家重点实验室,大连116024 [3]中国电建集团昆明勘测设计研究院有限公司,昆明650051

出　　处：《振动与冲击》2020年第2期169-177,共9页Journal of Vibration and Shock

基　　金：国家重点研发计划(2016YFB0201001)

摘　　要：高土石坝抗震可靠度研究对大坝抗震防灾和震害风险研究具有重要意义。通过考虑地震动和筑坝料参数双重随机性,建立基于地震易损性和地震峰值加速度概率密度函数的高土石坝抗震可靠度模型,为研究不同设计使用年限的高土石坝抗震可靠度提供依据。通过拉丁抽样方法选取筑坝料参数样本并与选择地震动组合成样本对,选取坝顶相对震陷率作为性能参数,提出考虑抗震设防标准的高土石坝性能水平了;采用SWANDYNE Ⅱ程序进行动力计算,并根据改进云图法得到不同地震峰值加速度下坝顶相对震陷率的地震易损性三维曲面;结合糯扎渡高土石坝不同设计年限的概率分布函数与地震易损性曲面,确定不同设计年限失效概率和抗震可靠度。分析结果表明:随着设计使用年限增加,大坝各个性能水平可靠度不断减小,对于严重破坏状态下不同设计年限可靠度均能满足《水利水电工程结构可靠性设计统一标准》规范要求,说明糯扎渡高土石坝在变形方面抗震设计是合理的。The seismic reliability of high earth-rockfill dams is of very significance in the study of earthquake resistance,disaster prevention and risk assessment of earthquake damage of dams.Considering the double randomness on seismic ground motions and dam material parameters,a seismic reliability model for high earth-rockfill dams based on seismic fragility and the probability density function of peak acceleration was established,which provides a basis for the seismic reliability estimation of high earth-rockfill dams with different design working life.The samples of dam material parameters were selected by Latin sampling method and combined with selected ground motions to compose sample pairs.The crest relative seismic settlement was selected as the performance parameter and the fragility performance level considering the seismic fortification standard was proposed.Then,the SWANDYNE Ⅱ program was utilized to calculate the dynamic responses of the dam.By virtue of an improved cloud method,the seismic fragility 3D surface of the crest relative seismic settlement under different peak acceleration was obtained.According to the probability distribution function of the Nuozhadu high earth-rockfill dam with different design years and the seismic fragility surface,the failure probability and seismic reliability of the dam with different design years were determined.The analysis results illustrate that with the increase of design working life,the seismic reliability of each performance level of the Nuozhadu dam decreases continuously,and the reliability of the dam with different design life can all satisfy the requirements of the unified standard for the reliability design of hydraulic and hydropower engineering structures in the condition of serious damage.The seismic reliability analysis of the Nuozhadu high earth-rockfill dam indicates that its seismic design is reasonable from the viewpoint of deformation.

关 键 词：抗震可靠度 概率密度函数 SWANDYNEⅡ程序 改进云图法 

分 类 号：TV641[水利工程—水利水电工程]