摘要
CRTSⅡ型轨道板为单向预应力结构,钢筋采用低松弛无粘结预应力钢筋。在轨道板张拉工序中,由于自重的影响,钢筋在轴向拉力的作用下会引起径向的垂度变形,预应力钢筋产生的端点位移不仅与钢筋的横截面积、弹性模量有关,还与其垂度大小密切相关,因此,需要考虑预应力钢筋抗弯刚度的影响。为此,引入垂度折减系数概念,对工作状态下钢筋的跨中挠度计算公式进行理论推导,从而近似修正钢筋自身的垂度效应。同时详细分析了垂度折减系数与预应力钢筋的长细比及张拉轴向应力的非线性关系。
CRTS Ⅱ gravelless rail board is a unidirectional prestressed structure, and the steel bar uses low relaxation unbonded prestressed steel bar. In the gravelless rail board prestressed process, the steel bar will cause radial stiffness and deformation under the action of axial force because of its own weight. The endpoint displacement of prestressed steel bar is related to the cross - sectional area of the steel, elastic modulus, and also closely related to sag, therefore we need to consider the reinforced effect of bending rigidity. This paper introduces the coefficient of stiffness reduction in order to deduce the theory of steel bar deflection calculation formula and approximately correct the reinforcement stiffness effects. At the same time, this paper analyzes the nonlinear relationship between coefficient of stiffness reduction and prestressed steel bar＇ s slender ratio as well as axial stress.
出处
《石家庄铁道大学学报（自然科学版）》
2013年第3期107-110,共4页
Journal of Shijiazhuang Tiedao University(Natural Science Edition)
关键词
CRTS
Ⅱ型轨道板
张拉
抗弯刚度
垂度折减系数
CRTS Ⅱ gravelless rail board
tension
flexural rigidity
coefficient of stiffness reduction
