水平加强层对钢框架结构抗连续倒塌性能的影响

为研究水平加强层对钢框架结构抗连续倒塌性能的影响，利用ANSYS有限元软件，以一幢10层钢框架结构为原型，根据支撑的设置方式建立了4种有限元模型，采用备用荷载路径法，将不同底层柱突然失效分为8种工况，对每种工况下的4种模型进行了动力非线性分析。分析结果表明：底层柱失效后，水平加强层可以有效提高结构的整体拉接力，从而显著减小破坏部位的竖向位移，并将荷载传递至失效柱的临近柱，避免结构构件发生屈服造成结构刚度的下降。在底层柱上方增设水平加强层可以以较低的造价增强结构的整体性，增强钢框架结构发生局部破坏后的内力重分布能力，提高抗连续倒塌能力。

Effects of horizontal strengthening storey on progressive collapse resistance of steel frame structures

To investigate the effects of the horizontal strengthening storey on the resistance of steel frame structures against progressive collapse, four finite element models of 10 storey steel frame structure, differing in the arrangement of bracing, were developed with the software of ANSYS. The situation of different columns on the first floor removed was classified into eight scenarios,and four models of each scenarios were analyzed with nonlinear dynamic analyses. The results of nonlinear dynamic analyses indicate that the horizontal strengthening storey can improve the integrity of structures to noticeably reduce the vertical displacement above the removed columns, transfer the loads to the columns adjacent with the removed columns, and prevent the decrease of the stiffness of the structures due to the yield of the members. Locating horizontal strengthening storey above the columns on the first floor does not increase the cost of the building but increases the load paths after the loss of the columns, and improves the progressive collapse resistance of the structures.