钢筋混凝土圆管涵受力破坏实验研究

钢筋混凝土圆管涵是公路设施的一个重要结构物,对三个圆管涵样本进行实验并结合有限元分析,详细研究了圆管涵的开裂荷载、荷载-挠度关系等力学特性,得出圆管涵开裂荷载约为50 kN/m。圆管涵在外力作用下,开始时随着荷载的增加,挠度逐渐增加,荷载-挠度呈线性关系,当荷载达到一定值后,再继续增加荷载,挠度迅速增加直至圆管涵破坏。涵管端部的竖向变形比涵管中部的变形大,涵管中部的横向变形比涵管端部的变形大,涵管竖向变形比横向变形大。涵管顶部和底部的内壁几乎同时开裂,但管顶裂缝宽度比管底发展快,内壁裂缝较少。外壁侧面比内壁开裂要晚,裂缝较多,分布较广,裂缝宽度发展缓慢,没有明显的主裂缝。涵管结构设计时裂缝控制应以内壁的裂缝为主。

Experimental Study on Force Damage of Reinforced Concrete Pipe Culvert

The round pipe culvert of reinforced concrete is an important structure of highway facilities.Combined with the experiment of three round pipe culvert samples and the finite element analysis,the mechanical characteristics of round pipe culvert were analysed in details,such as cracking load and load-deflection relation.It was concluded that the cracking load of round pipe culvert was about 50 kNm.Under external force,at first the deflection of round pipe culvert increased gradually with growing load and the relationship of load-deflection was linear,however when the load reached a certain value,the deflection increased rapidly until the round pipe culvert was destroyed.The vertical deformation at the end of the round pipe culvert was larger than that of its central part,whereas the lateral deformation of the central part was larger than that at the end.The inside wall of pipe＇s top and bottom part almost crazed at the same time,but the crack width at pipe top developed quickly than that at pipe bottom,whereas the inside wall cracks were less at pipe top.Compared to the inside wall,there were more cracks in the outside wall with wider distribution,the width of which developed slowly without apparent main crack.The structure design of round pipe culvert should give priority to the crack control of its inside wall.