受振动影响的现浇钢筋混凝土梁力学性能研究

Research on Mechanical Properties of Cast-in-place Reinforced Concrete Beams Affected by Vibration

为了研究不中断交通桥梁拓宽时行车振动对现浇钢筋混凝土结构的承载力、刚度、开裂形态、钢筋及混凝土应力状态的影响,开展了试验和理论研究。首先进行了振动中不同长度后浇筑段钢筋混凝土梁的试验,在此基础上,使用试验测得的钢筋与混凝土黏结滑移关系,进行了有限元数值模拟分析。研究结论表明:后浇筑段黏结性能下降对钢筋混凝土梁的承载力和刚度基本无影响;随着后浇筑段长度增加,裂缝开裂区域变小、裂缝数量减少,跨中钢筋应力相近区段变长,混凝土的受压区域增大,受拉区域减小。

In order to study the influences of vibration on the load-bearing capacity,stiffness,form of cracking,stress state of rebar and tension and compression stress state of concrete during the widening of bridge without interruption of traffic,the experiment and theoretical study are carried out.The test of reinforced concrete beams with different length of post-cast section is carried out under vibration conditions,and the bond slip relationship between rebar and concrete is obtained,then the finite element numerical simulation is carried out.The results show that the decrease of bond performance in the postcast section has no impact on the bearing capacity and stiffness of reinforced concrete beams.With the increase of the post-cast section lengths,the cracking area becomes smaller,the number of cracks are reduced,the length of rebar with same stress are longer in mid-span,the concrete compression area are increased,and the concrete tension areas are reduced.