Seismic demands on columns that belong to 10-, 14- and 18-story buildings structured with ductile concentrically braced frames (CBF) in a chevron configuration are studied in this paper. Buildings were carefully designed following principles of the capacity design philosophy, and they were virtually located in a soft soil condition. The research explores a more realistic assessment of the axial and bending demands on the columns of braced bays for a safe and economical design. Based on the statistical results of detailed nonlinear analyses, a procedure for estimating the axial design load in the columns of braced frames is proposed for mid- and high-rise buildings to obtain a conservative prediction of the demand. The methodology depends on the story where the column is located and the expected capacity of the bracing system calculated from a participation factor. Furthermore, a relationship between the building height and the accuracy of the prediction is underlined. The study also provides some detailed background behind the design procedure of CBF from specialized codes and compares the efficiency of published methodologies to estimate the design demands.

本文研究了属于 10 层、14 层和 18 层建筑物的柱子的抗震要求，这些建筑物采用人字形配置的延性同心支撑框架 (CBF) 构成。建筑物是按照容量设计理念精心设计的，它们实际上位于软土条件下。该研究探索了对支撑隔间柱的轴向和弯曲要求进行更现实的评估，以实现安全和经济的设计。根据详细非线性分析的统计结果，提出了一种估算中高层建筑支撑框架柱中轴向设计荷载的程序，以获得对需求的保守预测。该方法取决于柱所在的楼层以及根据参与系数计算的支撑系统的预期容量。此外，强调了建筑物高度与预测精度之间的关系。该研究还提供了一些来自专业代码的 CBF 设计程序背后的详细背景，并比较了已发布方法的效率，以估计设计需求。