钢筋混凝土简支斜交宽梁桥动力特性分析

以省道306线福建永春达中桥为例,分析了钢筋混凝土简支斜交宽梁桥的动力特性.首先介绍了全桥现场环境振动试验的概况;然后利用频域中的峰值法(PP)和时域中的随机子空间识别法(SSI)分别进行桥梁模态参数识别;最后利用ANSYS建立了全桥三维有限元模型并进行了理论模态分析,得到了该桥的前9阶频率和振型,其理论计算和实测结果吻合较好.结果表明,斜交宽梁桥具有竖向多扭转振型的特点,进行竖向模态测试时需布置3排加速度传感器.

Dynamic analysis of a simple-supported skewed and wide reinforced concrete bridge

As an example of Dazhong bridge in the line of No.306,located in Yongchun county,Fujian Province,the dynamic behavior of a simple-supported skewed and wide reinforced concrete bridge was investigated.The ambient vibration field-testing were firstly carried out.Secondly,the peak picking(PP) method in frequency domain and the stochastic subspace identification(SSI) method in time domain were used for the output-only modal parameter identification.Furthermore,the 3-D finite element(FE) model were constructed by using ANSYS program and the theoretical modal analysis was then performed to generate natural frequencies and mode shapes in the 3-orthogonal directions.The first 9 frequencies and modal shapes were extracted from the analysis.The results from the analysis are corrected well with that from the testing,the result reveals that more torsional modes exist in such type of bridge and three rows of acceleration sensors should be arranged in vertical mode's testing.