预应力混凝土箱梁砸击后损伤检测与仿真分析

该文以常州市某大桥引桥为对象,研究探讨了砸击事故对预应力混凝土箱梁桥总体技术状况和安全性能的影响。结果表明:砸击事故造成引桥桥面铺装与箱梁顶板面积约(1.5×1.5)m2的区域直接被砸穿,箱梁顶板3根纵向、3根横向预应力钢筋被砸外露且局部下凹变形,主筋被砸弯。有2个箱室顶板混凝土受冲击破碎、劈裂、脱空,腹板与顶板交接处纵向开裂,腹板混凝土产生5条斜向裂缝。纵向预应力筋锚固齿板混凝土在顶板连接处破碎,钢筋露出。在假定的砸击荷载作用下,理论仿真分析顶、底板及腹板受损面积略大于实测结果。

Inspection Testing and Simulating Analysis of Hit Injury of Pre-stressed Concrete Box Beam

Taking an approach of bridge in Changzhou as an example,the article discusses the influence of hit accidents on the master technical status and safety property of pre-stressed concrete box-beam bridge.The result makes clear that the area about(1.5×1.5) m2 of the deck pavement of the approach bridge and the top plate of box beam is directly broken by the hit accident,the three-longitudinal and three-transverse pre-stressed reinforcement at the top plate of box beam is hit to expose and is partially concave to deform,and the main bar is bent into by a hit.The concrete at the top plate of two box chambers is broken up,split off and voided.The connection zone of web and top plate cracks vertically and the web concrete produces five inclined cracks.The longitudinal pre-stressed tendon anchorage tooth plate concrete is broken at the top plate and its reinforcement is exposed.Under the assumed hit load,the theoretical simulation analyzes that the injury area of top,bedplate and web is slightly larger than the measured result.