基于协同工作原理的框架-核心筒结构框剪比研究

Study on the frame-shear ratio of frame-core tube structure based on the cooperative work principle

基于框架-核心筒结构协同工作原理建立变刚度条件下的等效连续化简化分析模型,通过力平衡关系和位移协调条件建立微分方程,并结合边界条件采用数值方法求解,得到变刚度框架-核心筒结构在倒三角分布侧向力作用下的剪力分配规律。从双重抗侧体系协同工作角度揭示了框剪比这一指标的物理意义、分布规律以及影响因素。分析表明,框剪比数值大小与结构刚度特征值、结构顶部与底部的刚度比以及沿高度的刚度变化速率相关,变刚度条件下框剪比分布规律与一致刚度相比有明显差异。根据分析结果对现行规范和超限审查技术要点中关于框剪比的规定进行了探讨。

Based on the cooperative work principle of frame-core tube structure,a simplified and equivalent continuum analysis model with nonuniform lateral stiffness distribution is established.The differential equation is derived by force balance relation and displacement coordination condition.Solving the equation by numerical method combined with boundary conditions,the shear force distribution law of frame-core tube structure with nonuniform lateral stiffness under the inverted triangular distribution lateral force is obtained.The physical meaning,distribution and influencing factors of the frame-shear ratio index are revealed from the angle of the cooperative work of the dual system.The analysis shows that the value of frame-shear ratio is related to the stiffness characteristic value,the ratio of stiffness at the top to the bottom and the rate of stiffness change along the height.The frame-shear ratio distribution of frame-core tube with nonuniform stiffness is obviously different from that with uniform stiffness.Based on the analysis results,the provisions on the frame-shear ratio in the current code and the technical points of expert panel review for seismic design of over-limit high rise buildings are discussed.