中文摘要：

研究目的：针对既有线32 m简支T型梁桥在列车提速时横向刚度不足、振幅过大以及重载列车过桥时承载力不足的问题,提出通过预制混凝土横隔板及体外预应力钢绞线对桥梁进行横向和纵向复合快速加固方法,通过ANSYS和多体动力学软件UM（Universal Mechanism）进行桥梁加固前后静力性能以及车桥耦合动力性能分析。研究结论：（1）提速列车过桥时主要问题是横向振幅过大,而横向加固能够有效提高梁体的横向刚度,使桥梁的横向一阶、扭转一阶自振频率显著提升,减小列车过桥时的动力响应;（2）重载列车过桥时主要问题是承载力不足,竖向挠度过大,竖向加固在提高承载力和竖向一阶自振频率的同时,会导致梁体的横向自振频率变小,需在纵向加固同时进行横向加固;（3）证明了车桥系统共振理论推导公式计算结果的正确性以及桥梁加固后发生共振时桥梁的安全性;（4）加固后桥梁能够满足提速列车以及重载列车运营要求;（5）此加固方法适用于工期紧张且不能中断运营的铁路既有简支桥梁的加固。

英文摘要：

Research purposes： The lateral stiffness and load - bearing capacity of existing 32 m simply - supported concrete T - beam railway bridges fail to meet the needs because of train speed raising and development of heavy train. In order to solve these problems, the quick reinforcement methods that use external prestressing tendons and precast concrete diaphragm plate are studied. Dynamic interaction between train and bridge is studied through ANSYS and multi -body dynamics software UM. Research conclusions： （ 1 ） Results of the vehicle - bridge simulation indicate that the main problem of the existing bridge when high - speed train pass through is the lateral amplitude of vibration is too large, lateral reinforcement can effectively improve the lateral stiffness and enhance univalent lateral natural vibration frequency and univalent torsion natural vibration frequency. （2） The main problem of the existing bridge when heavy train passed through is the poor load- bearing capacity and the excessive vertical deflection. Vertical reinforcement can improve the load -bearing capacity and univalent vertical natural vibration frequency, at the same time it will lead to the beam~ lateral vibration frequency becoming smaller. So lateral reinforcement and vertical reinforcement should be done at the same time. （3） The validity of vehicle - bridge system＇ s resonance principle and the reliability of resonance response of the reinforcement bridge are requirements of relevant all confirmed. （4） After reinforcement the dynamic regulation. （5） This reinforcement methods can be used supported beam bridge when time is very tense and the railway operation can＇t responses of bridge and train can meet for the existing railway concrete simply - be interrupt.