大跨悬索桥伸缩缝状态分析与处理措施

Condition Analysis and Handling Measures for Expansion Joints of Long Span Suspension Bridges

为及时发现大跨悬索桥伸缩缝的病害、分析造成悬索桥伸缩缝病害的主要原因,依托江阴长江公路大桥、润扬长江公路大桥南汊桥2座悬索桥,基于健康监测系统实测数据的伸缩缝状态评估一般方法,对悬索桥伸缩缝状态进行分析,并对比分析了悬索桥与斜拉桥伸缩缝运动特性,提出了伸缩缝病害处理措施。根据分析可知,悬索桥与斜拉桥纵向位移特性具有较大差异性,累积纵向位移过大和较大冲击是造成悬索桥伸缩缝损坏的重要原因。可采取更换耐磨性能更好的滑块材料、增加位移约束装置、安装梁体纵向阻尼器等措施以改善大位移伸缩缝使用性能及使用寿命,并已成功应用在江阴长江公路大桥和润扬长江公路大桥南汊桥中,取得了良好效果。

To timely find out the damage of expansion joints in long span suspension bridges and to analyze the main causes leading to the damage,the expansion joints of two long span suspension bridges of Jiangyin Changjiang River Highway Bridge and the South Bridge of Runyang Changjiang River Highway Bridge were cited as the examples.Based on the general method for condition evaluation of the large movement expansion joints of the measurements from the structural health monitoring system,the condition analysis of the expansion joints of the suspension bridges was made,the movement characteristics of the expansion joints of the two suspension bridges and a cable-stayed bridges were compared and accordingly the handling measures for the damage to the expansion joints were put forward.In accordance with the analysis,it was considered that the longitudinal displacement characteristics of the suspension bridges and cable-stayed bridge had distinctive differences and it was concluded that the excessive cumulative longitudinal displacement and the great passing vehicle impact were the main causes leading to the damage to the expansion joints of the suspension bridges.The measures of replacing with the sliding block material with better abrasion performance,adding the movement constraint device and installing the longitudinal dampers on the girders might be taken to improve the service performance and life of the expansion joints.These measures were eventually successfully taken for the expansion joints in the two example suspension bridges mentioned above and sound effect of the measures was achieved.