介绍一种新型的预应力混凝土叠合梁——二次预应力混凝土叠合梁,分析其设计特点;并应用于高速铁路无碴轨道桥梁中,根据设计实例进行应力分析,与相同截面尺寸的常规预应力混凝土梁的应力进行对比。结果表明:与常规预应力混凝土梁相比,二次预应力混凝土叠合梁受力合理,可以明显减小截面应力梯度,对减小梁的徐变上拱非常有利;并可以节约预应力筋约10%,具有明显经济优势。 A new type of prestressed concrete composite beam-secondary prestressed concrete composite beam is introduced to analyze the design features of the composite prestressed concrete beam. The beam is applied to the ballastless track bridge of high-speed railway. The stress analysis is carried out according to the design example, The stress of conventional prestressed concrete beams is compared. The results show that compared with conventional prestressed concrete beams, the stress of secondary prestressed concrete composite beams can be significantly reduced, which can reduce the cross-section stress gradient greatly and reduce the prestressing force of tendons about 10% %, With obvious economic advantages.