中文摘要：

为研究大跨度体外预应力钢－混凝土组合结构桥梁的动力行为，分析推导了钢－混凝土组合结构桥梁的等效阻尼比的计算公式，深入探讨了组合梁剪力连接件群的抗剪刚度及界面滑移、体外预应力作用效应、下部桩－土相互作用对钢－混凝土组合结构桥梁动力特性的影响。有限元计算及结果表明：组合结构桥梁的等效阻尼比对体系的动力响应影响显著；组合梁剪力钉群的抗剪刚度及体外预应力作用水平对大跨度组合结构桥梁的自振频率均有不同程度的影响．但相对较小；桩－土相互作用对大路唐组会结柏桥粱的动力特性影响明显。

英文摘要：

In order to investigate the dynamic behavior of long-span steel-concrete composite bridge with external tendons, the formula of equivalent damping ratio on steel-concrete composite bridge is analyzed and derived, the influence of shear stiffness of shear connectors of composite beam, interface slip, effect of external tendons, pile-soil dynamic interaction on the dynamitic property of steel-concrete composite bridge is discussed. The finite element calculation indicates that （ 1 ） the equivalent damping ratio of the composite bridge has significant influence on the dynamic response; （2） the shear stiffness of grouped stud shear connectors and the prestressed level of external tendons have different but relatively smaller influence on the nature frequency of long-span composite bridge; （3） the influence of pile-soil dynamic interaction on the structural dynamic response of the composite bridge is obvious.