波纹钢腹板组合箱梁常幅疲劳性能试验研究

发布时间：2019-04-24 19:36

【摘要】：波纹钢腹板组合箱梁结构以波纹钢腹板代替传统的混凝土腹板,实现了主梁的轻型化。针对波纹钢腹板组合箱梁的破坏机理,研究了2根波纹钢腹板组合箱梁的静力和疲劳性能。记录了试验中裂纹萌生、扩展的全过程,分析了试件破坏模式、承载力、荷载挠度曲线、荷载应变曲线,并通过材料力学公式对100 k N时梁挠度进行计算。结果表明:箱梁破坏时纵向裂纹萌生于混凝土底板,纵向贯通拉裂后,波纹钢腹板与底板之间产生纵向滑移,混凝土销剪切错动破坏。实际工程中应对混凝土底板进行FRP加固或设置预应力筋减缓裂纹萌生以及扩展;箱梁具有很好的疲劳耐久性,疲劳试验中裂纹扩展缓慢,当P_(max)为静力试验承载力的50%时,疲劳寿命超过6×106周次;箱梁受力符合拟平截面假定,混凝土顶底板主要承受弯矩,波纹钢腹板主要承受剪力。挠度计算结果略小于试验值,属于偏安全计算,误差原因主要是未考虑波纹钢腹板剪切变形对梁挠度影响。
[Abstract]:The corrugated steel webs are used to replace the traditional concrete webs in the corrugated steel web composite box girder structure to realize the lightweight of the main beam. According to the failure mechanism of corrugated steel web composite box girder, the static and fatigue properties of two corrugated steel web composite box girder are studied. The whole process of crack initiation and propagation in the test is recorded. The failure mode, bearing capacity, load deflection curve and load strain curve of the specimen are analyzed. The deflection of the beam is calculated by the material mechanics formula. The results show that the longitudinal cracks occur in the concrete floor when the box girder is destroyed, and the longitudinal slip occurs between the corrugated steel web and the bottom plate after the longitudinal continuous tensile cracking, and the shear failure of the concrete pin is staggered. In practical engineering, the concrete floor should be strengthened with FRP or pre-stressed tendons should be set to slow down the crack initiation and propagation. The box girder has good fatigue durability and the crack propagation in fatigue test is slow. When P _ (max) is 50% of the static test bearing capacity, the fatigue life is more than 6 脳 10 ~ 6 cycles. The stress of box girder accords with the assumption of quasi-plane section. The concrete roof and floor mainly bear bending moment and corrugated steel webs mainly bear shear force. The result of deflection calculation is a little less than the experimental value and belongs to partial safety calculation. The error is mainly due to the failure to consider the effect of shear deformation of corrugated steel webs on the deflection of the beam.
【作者单位】：四川大学建筑与环境学院;四川大学深地科学与工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(51408382) 四川省科技支撑项目(2015GZ0245)
【分类号】：U446.1

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