军山长江大桥钢-UHPC组合桥面改造效果研究

Study of Implementation Effect of Steel-UHPC Composite Bridge Deck on Junshan Changjiang River Bridge

武汉军山长江大桥原桥面铺装为双层SMA,随着车流量的增加和超重车辆的影响,运营多年后该桥正交异性钢桥面板出现疲劳裂缝。为处治桥面板隐性裂缝,分别对上游侧进行了钢桥面冷拌环氧树脂桥面铺装及桥面板焊接施工,对下游侧进行钢-UHPC组合桥面铺装改造。为评估钢-UHPC组合桥面的改造效果,基于已建立的运营期安全监测系统及有针对性的增布动应变测点,对随机荷载作用下桥梁上、下游侧桥面板的局部应力进行测试。结果表明:在下游侧的车辆数量和轴重均高于上游侧的情况下,下游侧测点的等效应力幅大多小于对应的上游侧,表明钢-UHPC组合桥面铺装明显改善了该桥正交异性钢桥面板的疲劳应力。

The original deck pavement of Junshan Changjiang River Bridge in Wuhan consisted of two layers of SMA.As the increase of traffic volume and influence of heavy vehicles,fatigue cracks occurred in the orthotropic steel deck of the bridge after years of operation.To treat the hidden cracks in bridge deck,the upstream half of the deck was paved with cold mixed epoxy resin pavement,and deck welding was also done,whereas the downstream half of the deck has got the steel-UHPC composite deck pavement.To evaluate the rehabilitation effect of the steel-UHPC composite deck,local stresses in both the upstream half and downstream half of the deck were tested under the action of random loads when dynamic strain testing points were purposely added,based on the existing safety monitoring system in the operation period.The results show that when the traffic volume and axial loads on the upstream half of the deck are larger than those on the downstream half,the equivalent stress range of the downstream testing points is basically lower than the corresponding testing points on the upstream half,which proves that the steel-UHPC composite deck pavement significantly improves the fatigue stress of the orthotropic steel deck of the bridge.