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能模拟车辆荷载通过效应的疲劳模型试验是研究正交异性钢桥面板疲劳性能的有效手段。利用国内首台自主研发的桥面结构专用轮式滚动疲劳加载装置,以广东虎门二桥坭洲水道桥为依托工程,研究了基于轮式滚动加载的正交异性钢桥面板疲劳试验设计问题。首先,根据实桥交通需求分析,合理确定实桥疲劳荷载谱;其次,计算疲劳敏感部位热点在疲劳荷载谱各车型作用下的应力历程,采用雨流计数法计算应力谱,根据Miner疲劳损伤累积理论转化为每种车型通过1次的等效应力幅,结合交通量预测计算实桥各构造细节在设计寿命期内的疲劳累积损伤;最后,根据设备性能参数,分别计算橡胶轮双轴加载和钢轮单轴加载下试验模型各细节的等效应力幅,通过与实桥钢桥面板各细节的疲劳累计损伤等效,从而确定试验加载轴类型、加载水平以及对应各细节的等效作用次数。研究成果对改进正交异性钢桥面板疲劳试验设计有重要参考意义。
The fatigue model test, which can simulate the passing of vehicle load, is an effective way to study the fatigue property of orthotropic steel bridge deck. The fatigue test design of orthotropic steel bridge deck based on wheeled rolling loading was studied by using the first wheeled rolling fatigue loading device specially developed for bridge deck structure in China and the Weizhou Chau Bridge on the second Humen Bridge in Guangdong Province. First of all, based on the analysis of real-bridge traffic demand, the fatigue load spectrum of real bridge is reasonably determined. Secondly, the stress history of fatigue-sensitive hot spots under fatigue load spectrum is calculated, and the stress spectrum is calculated by rain flow counting method. The theory is transformed into the equivalent stress amplitude of one vehicle passing through each type of vehicle and the traffic volume prediction is used to calculate the cumulative fatigue damage of each structural detail of the actual bridge in the design life. Finally, according to the equipment performance parameters, The equivalent stress amplitude of each detail of the test model under uniaxial loading is equivalent to the accumulated fatigue damage of the concrete bridge deck in order to determine the type of loading axis, loading level and the number of equivalent actions corresponding to each detail . The research results have important reference meaning for improving the fatigue test design of orthotropic steel bridge deck.