Research on Aseismic Behaviors of Reinforced Concrete Columns with Wallgirders Subjected by Two-directional Lateral Forces

单向梁钢筋混凝土柱在该方向与横向的剪跨比不同。因此，可以推断，在侧向力作用下产生的屈服铰在各个方向上出现的部位不同，而且两个方向上的破坏模式也可能不同。柱试件为30cm × 30cm方形截面，一个方向为主梁，另一个方向为梁，在三种墙梁高度、两种柱横向配筋率和两种侧向加载方案的组合下有六种变化。单向加载型是指在墙梁方向和梁方向交替进行反向加载。双向加载方式是指柱顶以椭圆轨道位移的循环加载方式。由于梁深增大使柱的变形长度变短，在屈服铰区所需位置增大，试验柱抗弯强度剪力大于计算值。结果表明，按序抗剪强度设计要求加抗剪配筋的柱在剪力梁方向失效。高抗剪配筋柱具有良好的抗弯强度和变形能力。梁向轴筋曲率或应变的最大值出现在柱开口部分的略外侧，梁向轴筋曲率或应变的最大值出现在柱端。双向侧向荷载作用下的极限抗弯强度和延性均小于单向荷载作用下的极限抗弯强度和延性，但滞回线的能量吸收均大于单向荷载作用下的滞回线。

Reinforced concrete columns with wallgirders in one direction have different shear-span ratios between in this direction and in transverse direction. Therefore it is conjected that yield hinges occured under lateral forces in the each direction appear at different portions from each other and also it may well be that failure modes are different between both directions.Column specimens with a square section of 30cm by 30cm having wallgirders in one direction and beams in the other direction, consist of six variations under combinations of three types of wallgirder height, two types of column transverse reinforcement ratios and two types of lateral loading program. One-directional loading type means reversal loading a alternately in the wallgirder direction and the beam direction. Two-directional loading type means cyclic loading as the tops of columns are displaced with elliptical orbits.According as deformable length of the columns became short using by large depth of wallgirders, experimental column shear force at bending strength was larger than calcurate valure because required lotations in the yield hinge zones weregreater. Consequently such columns with shear reinforcement required by ordinal shear strength design failed in shear in the wallgirder direction. However such columns with high shear reinforcement exhibited bending strengthand deformability. The maximum values of curvature or strain of axial column bars in wallgirder direction appeared at the slightly outer sides of opening portions in the columns, and ones in beam direction appered at the ends of columns. Ulimate bending strength and ductility under two-directional lateral loading were smaller, but energy absorption of hysteresis loops was larger in comparison with those under one-directional loading, respectively.