体外预应力在钢箱-混凝土组合梁中应用的试验研究

Experimental Research on Application of External Prestressing to Composite Steel-concrete Box Beam

结合城市桥梁工程实际,进行了3根钢箱-混凝土组合梁的试验。探讨了在对称和偏心荷载作用下,施加体外预应力对钢箱-混凝土组合梁受力性能的影响。试验结果表明,在对称荷载作用下,由于体外预应力的作用,钢箱-混凝土组合梁的弹性极限提高了29.17%,极限强度提高了27.72%,刚度提高了54.15%,位移延性提高了18.00%;在偏心荷载作用下,体外预应力钢箱-混凝土组合梁也有较好的力学性能,强度与刚度均高于普通钢箱-混凝土组合梁。试验研究证实,体外预应力技术对提高钢箱-混凝土组合梁的结构性能有重要作用。

Three composite steel-concrete box beams are tested combining with the engineering practice of urban bridge. Effects of external prestressing on mechanical performance of composite steel-concrete box beam under symmetrical and eccentric load are explored. The experimental results show that, under symmetrical load, the elastic limit, the ultimate strength, the stiffness and the deflection ductility of composite steel-concrete box beam are increased by 29.17%, 27.72%, 54.15% and 18.00% respectively due to the action of external prestressing.Under eccentric load, the composite＇steel-concrete box beam with external tendons has better mechanical performance,higher ultimate strength and stiffness than those of common composite steel-concrete box beam.The experimental rehash results proves that the external prestressing technique is important for improving the structural perforce of composite steel-concrete box beam.