在桥梁上,设计部分预应力混凝土应该有条件限制,首先活载占全部荷载的比值要在30％以上,否则经济性得不到体现。另外,桥梁有疲劳问题与裂缝开展的要求,如果设计中不限制裂缝开展,则不符合极限状态设汁的规定,同时还需满足挠度的限值。本文讨论限制裂缝开展设计部分预应力混凝土梁存在的问题,并通过示例阐明其设计步骤,同时与ACI方法进行对比。 On the bridge, the design of partially prestressed concrete should be conditional restrictions, first of all live load ratio of the total load to be more than 30%, otherwise the economy can not be reflected. In addition, the bridges have fatigue problems and crack initiation requirements. If the design does not limit the development of cracks, it does not meet the limit state of the provisions of the juice set, but also to meet the deflection limit. In this paper, we discuss the problems that exist in the design of partially prestressed concrete beams that limit the crack, and illustrate the design steps through examples. Meanwhile, we compare it with the ACI method.