连续刚构桥是我国桥梁工程中最常用的结构形式之一,已建此类桥梁普遍出现了跨中下挠过大的病害。以一实桥为工程背景,从控制弹性挠度不足、施工原因导致的有效预应力的降低、预应力摩阻损失、结构开裂、施工超方以及活载长期作用等方面,讨论了各因素对跨中下挠的影响程度。探讨通过对一些设计指标的控制、必要的构造措施以及合理施工方式的采取,来降低和消除可能出现病害的方法。 Continuous rigid frame bridge is one of the most commonly used structural forms in bridge engineering in our country. Based on Ishibashi as the engineering background, this paper discusses the influence of various factors on the cross-section of span, such as the control of the lack of elastic deflection, the decrease of effective prestress due to construction reasons, the loss of prestress friction, the structural cracking, The impact of the degree of deflection. This paper discusses ways to reduce and eliminate possible diseases by controlling some design indexes, constructing necessary measures and adopting reasonable construction methods.