【摘要】 为了研究在用简支梁桥的抗震性能,将弹性基础上桥墩的总变形分为三部分,即桥墩自身的弹性变形、基础转动和平动所产生的变形;以该变形曲线作为桥墩的振型函数,利用Lagrange方程推导了任意跨简支梁桥的横桥向地震振动方程,得到了相应的基频和振型参与系数的计算公式,在此基础上给出了包含地基综合参数在内的地震力的求解方法。利用冲击力锤法对室内模型桥进行了模态试验。试验结果表明:实测频率值与理论振型计算的频率值相差在5%以内,将桥墩的静力挠度曲线作为桥墩的振型函数是可行的;该计算方法可供简支梁抗震评估参考。更多还原

【Abstract】 In order to find out the seismic feature of the existing simply-supported beam bridges,the deformation function of pier sited on the elastic foundations is adopted as its fundamental vibration mode,which includes three parts: the elastic deformations only caused by force,and the deformations caused by the foundation’s rotation and translation.Then,the transverse seismic vibration equations of simply-supported beams with arbitrary span is conducted by Lagrange equation,and the formulas for its fundamental frequency and participation factors are derived,so the seismic force including foundation integration parameters can be calculated.A modal test using impact excitation method is carried out indoor.The results show that the frequency from the test has an error of 5% compared with the theoretical one,and the static deformation function can be effectively adopted as the pier’s fundamental vibration mode,so the method presented can give reference to the seismic evaluation of the existing simply-supported beam bridges.1 tab,3 figs,10 refs.更多还原