分段摇摆墙内力改进效果研究及影响参数分析

Study on the Improvement Effect of Rocking Wall Internal Force in Multiple Rocking Sections System and Analysis of Influencing Parameters

在保证对结构变形、抗震性能改进效果的情况下,采用分段摇摆墙的形式可有效降低摇摆墙自身的内力需求,并且该形式具有制作更简单、运输更便利、安装更简易的优势。为了分析摇摆墙采用分段形式后对摇摆墙内力的改进效果,文中结合分段摇摆墙的特征及与整段摇摆墙不同的边界条件,推导了铰接分段摇摆墙-框架结构的位移和摇摆墙内力的简化计算公式,并进一步开展了摇摆墙刚度比和摇摆墙分段数目对摇摆墙内力的影响效果分析,且与整段摇摆墙的相应情况进行了对比。研究结果表明:将摇摆墙分段可以大幅降低摇摆墙的内力峰值、缩小内力值的变化区间,在均匀荷载作用时各分段摇摆墙的弯矩和剪力分布规律类似,且整段摇摆墙的弯矩峰值是分段摇摆墙的m2倍、整段摇摆墙的剪力峰值是分段摇摆墙的m倍,而在倒三角形荷载作用下时,上段分段摇摆墙的弯矩和剪力比下段分段摇摆墙的大;刚度比在1.0~5.0这一适当的区间内变化时,刚度比对摇摆墙内力的影响效果明显,且影响程度随摇摆墙刚度比增大呈先增大后减小的规律,但当摇摆墙刚度比在此适当区间之外(无论取值过大还是过小),摇摆墙内力改变情况则对刚度比变化变得不敏感,此时刚度比对摇摆墙内力的改善效果不佳;分段摇摆墙内力幅值的降低幅度会随着分段数目的增加而减小,在采用分段摇摆墙时分段数目不宜过多。除此之外,通过分析还可得,刚度比与分段数目这两个参数对摇摆墙内力的影响效果相对独立,影响效应不耦合。

Using multiple rocking sections system can effectively reduce the internal force demand of the rocking wall itself while ensuring the improvement of structural deformation and seismic performance.This form also has the advantages of being easier to manufacture,transport,and install.In order to analyze the improvement effect of multiple rocking sections system on the internal force of the rocking wall,the paper derived a simplified calculation formula for the displacement of frame structure in multiple pinned rocking wall system and internal force of multiple pinned rocking wall by combining the characteristics of segmented rocking walls and different boundary conditions from rocking at base only system.And it further analyzed the influence of the rocking wall stiffness ratio and the number of rocking sections on the internal force of the rocking wall,which was compared with the corresponding situation of rocking at base only system.The research shows that the peak value and variation range of internal forces can be significantly reduced when setting multiple rocking sections over the height of rocking system in comparison to full slice rocking system.Under uniform distributed load,the distribution regularities of bending moment and shear force of each section of rocking wall in multiple rocking sections system is similar.Furthermore,the peak bending moment of the rocking wall in rocking at base only system is m2 times that of the rocking wall section in multiple rocking sections system,and the peak shear force of the rocking wall in rocking at base only system is m times that of the rocking wall section in multiple rocking sections system.However,when subjected to inverted triangle load,the bending moment and shear force of the upper rocking wall section are larger than those of the lower rocking wall section in multiple rocking sections system.The influence of stiffness ratio on rocking wall internal forces is obvious when the ratio varies in an appropriate scope of 1.0~5.0.When the stiffness ratio increases in this scope,the influence extent increases first and then decreases.When the stiffness ratio is not in this scope,whether too large or too small,the internal force of rocking wall is not sensitive to this parameter.At this point,the improvement effect of the rocking wall internal force by the stiffness ratio is not significant.The decreasing amplitude of rocking wall internal force decreases with the increase of the number of rocking sections,so when using multiple rocking sections system,the number of rocking sections should not be too large.In addition,the analysis also shows that the influence of the stiffness ratio and the number of rocking sections on the internal force of the rocking wall is relatively independent,and the influence effects are not coupled.