基于恒载零弯矩理论的预应力配束方法

Method of prestressing tendon layout based on zero bending moment of dead load theory

预应力混凝土桥普遍存在跨中下挠,其根本原因是桥梁结构在施工建设过程中积累了不平衡弯矩。为了从根本上解决此问题,减小不平衡弯矩,基于恒载零弯矩理论,研究了预应力混凝土桥的直线与曲线布束形式,推导了预应力配束的相关计算公式,建立了预应力混凝土桥的预应力配束方法,并通过算例进行分析,验证该方法的有效性,从而可以主动控制预应力混凝土桥的跨中变形。

Mid-span deflection is widely spreaded in prestressed concrete bridges, and the root cause is that the bridge structure in the construction process accumulated unbalanced moment. In order to fundamentally solve the problem, and reduce the unbalanced moment, based on zero bending moment of dead load theory, this paper studies the arrangement of tendon with beeline and curve in concrete bridges and deduces relevant calculation formulas of prestressing tendon layout. The method of prestressing tendon layout is established and verified to be effective by examples, and the mid-span deformation of prestressed concrete bridges is controlled initiatively.