钢筋混凝土双偏压柱的配筋计算方法研究

Research on reinforcement calculating method of biaxial loaded RC columns

钢筋混凝土框架在工程实际中一般为三维空间结构,框架柱在2个主轴方向同时作用弯矩,将其简化为单向偏心受压柱进行设计可能存在不安全。借鉴《混凝土结构设计规范》(GB50010-2010)给出的双偏压柱正截面承载力计算方法的基本原理,建立了采用迭代法对基于设计内力、配筋面积和中和轴位置建立偏微分方程组进行求解的改进双偏压截面设计方法。基于OpenSees平台建立悬臂柱的非线性有限元模型用于验证双偏压矩形柱的改进截面设计方法。以多个算例的配筋计算结果为例,对比了简化单偏压配筋方法和改进双偏压截面设计方法的差异,并采用非线性有限元模型验证了改进双偏压截面设计方法的准确性和收敛效果。

Reinforced concrete （RC） frames are generally three dimensional structures in actual engineering, and frame columns are suffered with moments of two principle axes. Simplifying the biaxial eccentric loaded columns as uniaxial eccentric loaded columns is perhaps unsafe. Based on the fundamental principles of computational method of normal section bearing capacity of biaxial eccentric loaded columns in the Code for Design of Concrete Structure （GBS0010-2010）, an improved reinforcement calculating method was established by using iterative method to solve the partial differential equations based on the internal force, reinforcement area, and position of neutral axis. Based on OpenSees platform, a nonlinear finite element model of cantilever column was established to validate the improved reinforcement calculating method of biaxial eccentric loaded column. Based on several computational re- suits of reinforcement, the difference between simplified reinforcement calculating method of uniaxial loaded section, and improved reinforcement calculating method of biaxial eccentric loaded section was identified. The accuracy and convergence effect of improved reinforcement calculating method of biaxial eccentric loaded columns was confirmed by means of the nonlinear finite element model.