多拱肋异型系杆钢拱桥动载试验分析

Dynamic Load Test Analysis of Multi-arch Rib Special-shaped Bowstring Steel Arch Bridge

摘要:

通过现场实际对多拱肋异型系杆钢拱桥进行动载试验，详细介绍了异型拱桥动载试验的主要工作内容、试验方法、试验结果分析等。通过现场测试与理论计算分析，桥梁结构各阶自振频率的实测值均比理论计算值大，表明桥梁实际结构刚度好于理论刚度，桥梁实测阻尼比0.145%~0.390%之间，属于正常范围，桥梁主要振型为主梁一阶扭转，拱肋横向一阶侧弯，拱肋的横向刚度相对较弱。桥梁在各行车工况下的实测冲击系数在1.04~1.20，与设计所用冲击系数1+μ=1.05较为接近，满足规范要求。

Abstract:

Through the actual dynamic load test of the multi-arch rib special-shaped bowstring steel arch bridge, the main test content, test method and test result analysis of the dynamic load test of the special-shaped arch bridge are introduced in detail. Through field test and theoretical calculation and analysis, the measured values of each order natural frequency of the bridge structure are larger than the theoretical calculation values, which indicate that the actual structural stiffness of the bridge is better than the theoretical stiffness. The measured damping ratio of the bridge is between 0.145% and 0.390%, which belongs to the normal range. The main vibration mode of the bridge is the first-order torsion of the main beam and the first-order lateral bending of the arch rib. The lateral stiffness of the arch rib is relatively weak. The measured impact coefficient of the bridge under various driving conditions is between 1.04 and 1.20, which is close to the impact coefficient 1 + μ = 1.05 used in the design, and meets the requirements of the specification.