空间钢构架混凝土柱抗震性能的试验研究

Experimental research on seismic behavior of concrete column with spatial steel frame subjected to low cyclic reversed load

空间钢构架是由横向和斜向缀条与纵向弦杆焊接而成的承重轻钢结构,将空间钢构架替代传统钢筋混凝土结构中的绑扎钢筋骨架,形成空间钢构架混凝土结构。为了研究空间钢构架混凝土柱的承载力与变形能力、延性等抗震性能指标及其变形和破坏机制,进行了3根空间钢构架混凝土柱和1根普通钢筋混凝土柱在低周反复水平荷载作用下的对比试验。试验表明:空间钢构架混凝土柱的初始刚度与传统钢筋混凝土柱的初始刚度基本相同,在试件屈服后,空间钢构架混凝土柱的刚度退化程度要比传统钢筋混凝土柱要缓慢,其延性要比条件相同的普通钢筋混凝土柱要大。当需要采用空间钢构架承受施工荷载、直接悬挂模板时,应按本文建议的施工和使用两个受力阶段进行设计计算。结合试验结果及其分析,提出了这种新结构的构造要求。

The load-bearing lightweight steel structure is built by welding tr ansverse and inclined lace bars on longitudinal chords, which is called the spat ial steel frame. The concrete structure with spatial steel frame is gained by su bstituting spatial welding steel frame for binding steel skeleton in reinforced concrete structure. In order to study the seismic behavior of concrete short col umn with spatial steel frame, including its bearing capacity, deformation capabi lity, ductility as well as failure mechanism, the comparison of the tests of 3 c oncrete columns with spatial steel frame and 1 reinforced concrete column subjec ted to low cyclic reversed load are carried out. The results of the tests showed that the initial stiffness of the concrete column with spatial steel frame is a lmost the same as that of the reinforced concrete column. The stiffness degradat ion of the concrete column with spatial steel frame is slower than that of the r einforced concrete column after yielding of the specimen. Under the same conditi ons, the ductility of the concrete column with spatial steel frame is better tha n that of the reinforced concrete column. The spatial steel frame bearing constr uction loads and directly hanging formwork must be calculated by two stage desig n method recommended in this paper. Based on the tests and analysis, the detaili ng requirements of such structure are presented.