带砌体填充墙框架弹性抗侧刚度计算方法对比分析

对于带砌体填充墙框架，当填充墙与框架紧密接触时，填充墙将会提高纯框架的侧向刚度，可能改变结构的平面及竖向侧向刚度分布，影响其在地震作用下的承载力及耗能能力等抗震性能。 为研究带填充墙框架在弹性阶段抗侧刚度的合理计算方法， 整理了以等效斜压杆模型为主的国内外相关计算公式， 并结合近年来带填充墙的框架在低周往复荷载作用下的试验， 将理论计算结果与试验实测值进行对比分析。结果表明： 在带填充墙的RC框架中，直接考虑填充墙弯曲变形和剪切变形得到的弹性阶段抗侧刚度计算值为实测值的1.94~8.05倍；在等效斜压杆模型中，斜压杆的宽度对抗侧刚度的计算结果影响很大；斜压杆宽度的取值应考虑填充墙与框架之间相对刚度的影响，其中MSJC提出的斜压杆宽度计算公式较为合理。

Comparative study on calculation methods of elastic lateral stiffness in masonry-infilled frames

For frames with masonry infill walls, when the infill walls are in close contact with the frames, the infill walls will improve the lateral stiffness of the pure frames and may change the plane and vertical lateral stiffness distribution of the structure, which will affect its bearing capacity, energy dissipation capacity and other seismic behavior under the action of an earthquake. In order to study the reasonable calculation method of the lateral stiffness of the frame with infill wall in the elastic stage, the relevant calculation formulas mainly based on the equivalent diagonal strut model were collected, and combined with the experimental investigations on frame with infill wall under the low reversed cyclic loading in recent years, the theoretical calculation results were compared with the measured values. The results showed that in the RC frame with infill wall, the calculated lateral stiffness of the elastic stage obtained by directly considering the bending deformation and shear deformation of the infill wall was 1.94 to 8.05 times the measured value; in the equivalent diagonal strut model, the width of the diagonal strut had a great influence on the calculation results of the lateral stiffness; the value of the width of the diagonal strut should consider the influence of the relative stiffness between the filling wall and the frame, and the calculation formula of the diagonal strut width proposed by MSJC was more reasonable.