体外预应力在钢箱-混凝土组合梁中应用的试验研究

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。

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

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 research results proves that the external prestressing technique is important for improving the structural performance of composite steel-concrete box beam.