带跨层预应力斜支撑的高层钢框筒结构静力性能研究

MECHANICAL BEHAVIOR RESEARCH OF HIGH-RISE STEEL FRAME-TUBE STRUCTURE WITH CROSS LAYER PRE-STRESSED INCLINED BRACE

对于高层钢框筒结构体系,风荷载起控制作用,结构顶层侧移、层间位移角不易控制,为提高钢框筒结构的抗侧能力,将柔性预应力索用于钢框筒结构,并运用SAP 2000有限元软件对跨层预应力支撑钢框筒结构和钢框筒结构的抗侧性能和剪力滞后效应进行分析、对比,进一步研究预应力支撑的初始预拉力、弹性模量、布置角度、截面直径和布置方式等参数对跨层预应力支撑钢框筒结构受力性能的影响。研究表明:对钢框筒结构施加预应力支撑,显著提高其抗侧能力,并改善结构局部的剪力滞后效应;跨层预应力支撑宜布置为45°左右的交叉剪刀形状;在实际钢框筒结构工程允许的范围内,预应力支撑应选取较大的弹性模量和直径。

For high-rise steel frame-tube structure, wind load plays a dominant role. Top lateral displacement and inter-story displacement angle are not easy to be controlled. In order to improve the lateral performance of the steel frame-tube structure, the flexible pre-stressed cables are used for steel frame-tube structure. In this paper, lateral performance and shear lag effect phenomenon of both cross-layer prestressed brace steel frame-tube structure and steel frame-tube structure are analyzed by using finite element software SAP 2000, and the results are compared. The mechanical behavior of cross-layer pre-stressed brace steel frame-tube structure, which is impacted by different pretension, modulus, layout angle, diameter and layout of pre-stressed brace, has been studied in this paper. It concludes that： pre-stressed cable could evidently improve steel frame-tube structure＇s lateral resistance and shear lag effect; cross- layer pre-stress brace should be arranged to cross a scissors shape, and its layout angle should be 45 degrees; pre-stressed brace with larger elastic modulus and diameter should be selected within the project of allowable range in the actual steel frame-tube structure.