预应力型钢混凝土梁静载及疲劳试验研究

Static Load and Fatigue Load Test Study of Prestressed Steel Reinforced Concrete Girder

为了探究疲劳荷载对预应力型钢混凝土梁服役性能的影响,设计了2根预应力型钢混凝土梁,分别对其进行静载破坏试验以及实桥等效应力水平下疲劳200万次后的静载破坏试验。通过测试型钢截面应变、梁体变形等分析了疲劳荷载作用对梁体刚度、裂缝发展的影响。研究结果表明:预应力型钢混凝土梁的破坏由正常使用极限状态条件控制;疲劳作用后裂缝发展速度加快,裂缝宽度明显增大,用裂缝宽度作控制指标则疲劳作用使梁的承载力降低了33%。

In order to explore the effect of fatigue load on the service performance of prestressed steel reinforced concrete girders,two prestressed steel reinforced concrete girders were designed in this paper. The static load failure test of the girders and the static load failure test after 2 million times of fatigue under the equivalent stress level of the real bridge were carried out respectively. The effects of fatigue load on the stiffness and crack development of girders were analyzed by measuring the strain of section steel and the deformation of girders. The results show that the failure of prestressed steel reinforced concrete girders is controlled by the limit condition of normal service. After fatigue,the crack development speed is accelerated,and the crack width is obviously increased. With the crack width as the control index,the bearing capacity of the beam is reduced by 33% due to fatigue.