整体式桥台桥梁的动力试验研究

Dynamic field-test of integral abutment bridge

研究了上坂大桥(中国最长的采用整体式桥台的无伸缩缝桥梁,简称为整体式桥台桥梁)在天然脉动荷载作用下的自振特性,得到关于该类桥梁自振特性的结论;采用结构分析软件ANSYS建立全桥的空间模型,计算该桥的自振特性,并与实测结果进行比较,结果表明:有限元模型具有较好的可靠性;实桥试验还测试了无障碍行车试验和跳车试验作用下桥梁的强迫振动特性,结果表明:该类桥梁的冲击系数值较大,而现行技术规范的取值值得商榷;此外该类桥梁具有较强的耗能能力,抗震性能较好。研究结果有助于对该类桥梁动力特性的认识和进一步开展无伸缩缝桥梁的抗震性能研究。

Shangban Bridge is the longest integral abutment bridge in China. In this paper, the characteristics of the natural vibration of this type of bridge are discussed firstly through the dynamic field-test of Shangban Bridge under environmental load. Then,the characteristics of the natural vibration of Shangban Bridge are calculated with the structure analysis software-ANSYS. Compared with the calculated results and the test results, it shows that the FEM model in the paper is credible. The vibratory characteristics of the structure are also tested under a traveling truck and a truck with obstacle. The result shows that the value of impact coefficient of the bridge is a little great, it is not appropriate to calculate the impact coefficient of integral abutment bridge by the corresponding criterion in China. Moreover, the seismic property of integral abutment bridge is well. The research results are helpful for the knowledge of dynamic characteristics of these bridges,furthermore,it is also helpful for research on the seismic properties of jointless bridge .