作　　者： (刘扬）; (周志彬）; (张海萍）;

机构地区： 长沙理工大学土木与建筑学院,湖南长沙410114

出　　处： 《公路交通科技》 2017年第9期86-92,共7页

摘　　要： 为了满足桥梁结构基于性能的抗震设计需求,提高桥梁抗震动力可靠度分析计算效率,提出一种基于支持向量回归(SVR)的桥梁抗震动力可靠度分析计算方法。该方法综合考虑了结构参数随机性和地震动激励随机性的影响。在ANSYS有限元分析软件中建立桥梁有限元数值分析模型,进行随机振动分析计算以确定结构在随机地震动激励作用下的响应功率谱;进而通过首次超越破坏准则得到桥梁结构在地震作用下的失效概率。采用均匀设计试验方法(UD)在结构参数样本空间选取合适的试验点,利用支持向量回归建立起结构参数与失效概率的对应关系式,再通过连续型随机变量的全概率公式得到结构在双重随机性下的失效概率。最后以一座主跨180 m的高墩大跨连续刚构桥为工程背景进行抗震可靠度分析计算,结果表明:采用UD-SVR方法拟合关于结构参数与失效概率的响应面函数进行可靠度分析计算,对复合随机系统的动力可靠度计算具有较高的效率,为复杂结构的抗震动力可靠度分析计算提供了一种新的思路。 In order to meet the requirements of performance-based seismic design of bridge structure and to improve the analysis and calculation efficiency of seismic dynamic reliability of bridges,a method for analysing and calculating seismic dynamic reliability of bridges based on support vector regression（ SVR） is proposed. This method takes into account the influence of randomness of structural parameters and randomness of seismic excitation. In the ANSYS finite element analysis software,the bridge finite element numerical analysis model is established,the response power spectrum of the structure under random seismic excitation is determined by random vibration analysis. And the failure probability of bridge structure under earthquake is obtained by using the first excursion failure criterion. Then,the appropriate test points in the sample space of the structural parameters are selected by adopting the uniform design test method,the corresponding relational expressions between structural parameters and failure probability are established by using SVR,and the failure probability of the structure under the double randomness is obtained by the total probability formula of the continuous random variable. Lastly,the seismic reliability analysis of a high-pier and long-span continuous rigid frame bridge with a main span of 180 m is conducted. The result shows that the method of fitting the response surface functions of structural parameters and failure probability by using UDSVR method and analyse the reliability has great efficiency in dynamic reliability calculation of compoundrandom system,which provides a new idea for the seismic dynamic reliability calculation of complex structures.

关 键 词： 桥梁工程 可靠度 支持向量机 刚构桥 随机振动 抗震