沿截面高度均匀配筋的钢筋混凝土偏心受压构件的配筋计算

新的混凝土结构设计规范(第二次送审稿)(以下简称新规范),给出了沿截面高度均匀配置纵向钢筋的矫形、T形、I字形截面钢筋混凝土偏心受压构件的正截面强度计算的近似公式,但是,如果构件属于小偏心受压构件,则在具体计算受拉区、受压区的钢筋面积时,首先需要求解相对中和轴高度ξ的三次方程,计算十分复杂。本文讨论了沿截面高度均匀配筋的偏心受压构件的各种计算情况,推导出了便于进行配筋计算的计算公式。对于小偏心受压构件,则应用“分区降阶逼近法”来求解ξ值。文中计算公式,可供工程设计人员实际应用。

THE STRENGTH CALCULATLON OF ECCENTRICALLY COMPRESSED REINFORCED CONCRETE MEMBERS WITH REINFORCEMENT IN FOUR FACES

An approximate strength calculation method of eccentrically compressed reinforced concrete members with reinforcement in four faces is given in the design of reinforced concrete structure. But for members with small eccentricity, a cubic equation of the relative neutral axis depth ξ should be solved in the reinforcement calculation, which is rather complicated. All the calculation conditions are systematically discussed and a convenient strength calculation method is deduced in this paper. The relative neutral axis depth ξ of the members with small eccentricity is solved using the approximation method by reducing power in separated regions.