大跨度斜拉桥拉索减振阻尼器的试验研究

Experimental study on cable dampers of long span bridges

在目前的技术水平条件下,试验是验证油阻尼器抑制斜拉桥拉索振动效果的最可靠手段。为研究某大跨度斜拉桥拉索阻尼器的性能,进行了包括阻尼器单体性能试验、双阻尼器及其实索固定装置组合系统足尺试验、阻尼器耐久性试验及阻尼器实索减振试验在内的全系列试验。详细研究了各种可能因素对阻尼器减振效果的影响,试验结果表明,试验阻尼器的力学性能与设计的线性特性吻合较好;支撑装置与连接件的缝隙不会降低阻尼器的减振效果;试验阻尼器具有良好的耐久性,并给出了阻尼性能随加载次数的退化规律表达式,供设计参考;试验阻尼器抑制实索振动的效果明显,经分析确定,拉索的边界条件是实索减振试验实测值与理论值两者之间产生误差的重要原因之一。

The stay cable can be easily excited to vibrate. Oil dampers are proposed to mitigate the cable vibration of a long span cable-stayed bridge. Based on previous studies, experiments are deemed necessary for evaluating the effectiveness of the dampers. A series of experiments were carried out, including preliminary tests on dampers alone, such as the performance test of a single damper, a full scale test of dampers with sockets, a durability test and a full- scale actual cable vibration mitigation test. Tests results indicate that the data match the design values well. The test setups to support the dampers would not degrade the damping effect. The test damper performs well after 4 million load cycles and a degenerated mode is provided to assist the damper design. The test damper is shown to be effective in the vibration mitigation of the stay cables. Because of the deviation of the full-scale cable vibration mitigation test results from the analytical results based on current theory, boundary condition was taken into consideration in both experimental and analytical studies.