桥梁伸缩缝锚固区混凝土界面力学性能分析

Analysis of the Interfacial Mechanical Properties of Concrete in the Anchorage Area of Bridge Expansion Joints

桥梁伸缩缝锚固区混凝土长期处于自然环境与车辆反复冲击荷载作用下,是伸缩缝结构最易发生破坏的部位,而锚固区与沥青铺装层界面间混凝土是最频繁出现开裂、破损及修复次数最多的部位。为研究两者界面处的力学性能,采用有限元软件建立伸缩缝及锚固区有限元模型,在最不利加载位置工况下,确定界面控制指标后,主要分析沥青弹性模量、锚固区宽度与厚度、车辆超载、水平力对界面受力的影响。结果表明,选择弹性模量较大的沥青材料、严禁车辆超载、避免车辆在锚固区处紧急制动,有利于降低界面应力与变形,锚固区宽度与厚度变化对界面应力影响不大,可根据施工经验与规范进行选择。

Concrete in the anchoring area of the bridge expansion joint has been in the natural environment for a long time,and under the repeated impact load of vehicles,which is the part of the expansion joint structure most likely to be damaged,and the concrete between the anchoring area and the asphalt paving layer are the part where cracking,damage and repairs occur most frequently.In order to study the mechanical properties at their interface,a finite element model of the expansion joint and anchorage area is established by finite element software.After determininginterface control index in the most unfavorable loading position,the influence of asphalt elastic modulus,anchorage area width and thickness,vehicle overload and horizontal force on the interfacial force is mainly analyzed.The results show that asphalt materials with large elastic modulus should be selected,vehicle overload should be strictly prohibited,and emergency braking of vehicles in the anchoring area should be avoided to reduce interfacial stress and deformation.Changes in the width and thickness of the anchoring area have little impact on interfacial stress,which can be selected according to construction experience and specifications.