基于Copula函数的预应力钢筋节点连接的装配式双柱混凝土桥墩主要失效模式分析

Analysis of Main Failure Modes of Assembled Double- column Concrete Piers Connected by Prestressed Steel Bars Based on Copula Function

目的研究地震作用下装配式双柱混凝土桥墩的主要失效模式,以提高其抗震性能.方法利用ABAQUS有限元软件对装配式双柱混凝土桥墩建立有限元模型.通过随机样本点,得到不同的功能函数,对比直方图的特征分析功能函数.对现浇桥墩和装配式双柱混凝土桥墩进行拟合以及对比分析,然后利用支持向量机法SVM计算桥墩失效概率.结果预应力双柱墩与现浇模型破坏接近,破坏的损伤均集中在桥墩塑性铰处,通过采用Copula二元分布函数考虑桥墩构件的相关性,得到现浇桥墩的失效概率为8.754×10-6,装配式桥墩的失效概率为3.513×10-7.结论装配式混凝土桥墩的失效模式多以应力-刚度为主,应力失效和刚度集中使得桥墩过早失效.同时预应力钢筋的存在也降低了桥墩的失效概率,大大提高了桥墩的抗震性能.

In order to study the main failure modes of assembled double-column concrete piers under earthquake in order to improve their seismic performance.In this paper,the method of artificial searching is The finite element model of assembled double column concrete pier is established by using ABAQUS finite element software.Latin hypercube sampling method is used to obtain the sample points of random variables.Different functions are used according to the sample data.The corresponding binary frequency histogram is drawn by using the distribution function corresponding to origin software.According to the graphic features drawn,a suitable Copula function is selected to fit and analyze the cast-in-place piers and assembled double-column concrete piers.Then the failure probability of piers is calculated by SVM.The result of the the damage of the prestressed double-column pier is close to that of the cast-in-situ model.The damage is concentrated in the plastic hinge of the pier.The failure probability of the cast-in-situ pier is 8.754×10-6 and the failure probability of the assembled pier is 3.513×10-7.The conclusion of the the model of cast-in-situ pier and assembled concrete double-column pier is established and analyzed by Copula function.The result of binary normal distribution function is in good agreement with the result of empirical distribution function.The error is less than 5%.At the same time,the existence of prestressed steel bars also reduces the failure probability of piers,greatly improving the seismic performance of piers.