反复荷载作用下的预应力混凝土梁变形  

Deformation of prestressed concrete beam under repeated loads

作　　者：赵煜[1,2] 张学广[1] 贺拴海[1] 

机构地区：[1]长安大学公路学院,陕西西安710064 [2]同济大学土木工程学院,上海200092

出　　处：《解放军理工大学学报（自然科学版）》2012年第3期292-297,共6页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金青年科学基金资助项目(50578014)

摘　　要：为了分析反复荷载对预应力混凝土梁变形性能的影响,对6片预应力混凝土模型梁进行了低频反复加载试验,在模拟实桥活载效应的荷载作用下,研究了不同预应力度的预应力混凝土梁变形性能和钢束有效预应力变化特征。结果表明,在反复荷载作用下,预应力混凝土模型梁残余挠度和荷载挠度(弹性挠度)较常量荷载下的对应值均有所增大,其中荷载挠度增大系数为1.05～1.10;反复荷载作用对预应力筋长期损失有较明显的影响,且预应力梁的残余挠度与预应力钢筋的残余变形有着密切关系。To study the influence of repeated loads on the deformation of prestressed beam, low-frequency repeated loads experiments of six PC T-girders were conducted, and the deformation characteristic and the effective prestress of the strands of the model beam investigated under the test loads which simulated the effect of the service load. The test results show that the residual deflection and the elastic deflection of the beam increase under 2 million repeated loads compared with that under the constant load. The amplifica- tion coefficient of the elastic deflection approximately lies between 1.05 and 1.10. Furthermore, the re- peated loads has obvious influence on the long-term prestress loss of the strands, and the residual deflec- tion of the PC girders has close relationship with the residual extension of the strands.

关 键 词：桥梁工程 预应力混凝土梁 挠度 有效预应力 模型试验 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]