基于F-R-M方法的桥梁地震风险评估研究

发布时间：2018-04-23 14:53

本文选题：桥梁 + 随机有限元　；参考：《广西大学学报(自然科学版)》2017年01期

【摘要】：为解决现有有限元分析方法对求解地震作用下桥梁的失效概率计算量大、耗时长的问题,建立了一种神经网络仿真与概率有限元相结合的桥梁地震风险评估方法(F-R-M法)。首先通过多条地震波对桥梁进行时程分析,并得到相应的桥梁结构的地震响应;然后建立RBF神经网络,并将量化后的地震波能量、场地类别、峰值个数、结构弯矩作为输入参数,对神经网络进行训练和检验,训练成功后可采用Monte Carlo方法生成大量随机数,通过神经网络仿真得到桥梁结构随机地震响应数据,并计算出结构的失效概率;最后以某三跨连续刚构桥为例,采用有限元软件建立了全桥纤维单元模型,选取了24条地震波对其进行了动力增量(IDA)分析,并采用F-R-M法对该桥的地震风险概率进行了评估。实例分析表明,F-R-M法计算效率高、计算误差小,神经网络RBF将地震响应和地震输入之间的非线性映射关系很好地仿真模拟,研究结果可为桥梁抗震设计和地震风险评估提供参考。
[Abstract]:In order to solve the problem that the existing finite element analysis method can solve the problem that the failure probability of bridges under earthquake action is large and time-consuming, a bridge seismic risk assessment method based on neural network simulation and probabilistic finite element method is proposed in this paper. The seismic response of the bridge structure is obtained by the time history analysis of multiple seismic waves, and then the RBF neural network is established, and the seismic wave energy, site category, peak number are quantified. Structural bending moment is used as input parameter to train and test neural network. After training successfully, a large number of random numbers can be generated by Monte Carlo method, and the random seismic response data of bridge structure can be obtained by neural network simulation. Finally, taking a three-span continuous rigid frame bridge as an example, the fiber element model of the whole bridge is established by using finite element software, and 24 seismic waves are selected for dynamic increment analysis. The seismic risk probability of the bridge is evaluated by F-R-M method. The analysis of examples shows that the F-R-M method has high calculation efficiency and small calculation error. The nonlinear mapping relationship between seismic response and earthquake input is well simulated by neural network RBF. The results can be used as reference for seismic design and seismic risk assessment of bridges.
【作者单位】：长安大学旧桥检测与加固技术交通行业重点实验室;湖北省交通运输厅工程质量监督局;西安科技大学建筑与土木工程学院;
【基金】：交通运输部应用基础研究项目(2015319812010) 陕西省社会发展科技攻关项目(2015SF265) 国家山区公路工程技术研究中心开放基金(gsgzj-2012-07) 陕西省自然科学基础研究计划项目(2013JQ7031) 中央高校基本科研业务费资助项目(3108211511070) 陕西省交通科技项目(15-19K)
【分类号】：U442.55

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