国家体育场柱脚锚固性能试验研究

Experimental study on anchorage performance of steel column base of National Stadium

大跨结构柱脚锚固性能是抗震设计的关键之一。国家体育场柱脚为钢柱脚,该钢柱脚锚固于钢筋混凝土承台中,其受力复杂,以往国内外类似的试验很少。笔者共进行了4个钢筋混凝土承台-钢柱脚试件锚固性能的试验研究,本文介绍其中2个几何尺寸较大的钢筋混凝土承台-钢柱脚试件锚固性能的试验研究概况,1个试件为混凝土承台中配置抗拔钢筋的试件,1个为混凝土承台中未配置抗拔钢筋的试件。通过单向重复加载下的钢柱脚锚固性能试验,对试件的锚固承载力、延性、合理配筋型式等进行了研究。试验结果表明,混凝土承台中配置抗拔钢筋的试件与未配置抗拔钢筋的试件相比其锚固承载力和延性显著提高。在试验基础上,建立了柱脚锚固承载力计算的桁架模型,计算结果与实测结果符合较好。

The anchorage performance of steel column base of large span structure is one of the key problems in seismic design. The steel column base of National Stadium is anchored in reinforced concrete pile cap, whose stress state is complex, and similar experiments were few in the past at home and abroad. Four experimental programs were carried out to study the anchorage performances of steel column bases, and two specimens of reinforced concrete pile caps-steel column base whose geometric size is big are introduced in this article. One is fitted up with an anti-punching shear bar and the other is not. Through the tests of the anchorage performances of steel column bases under uniaxial reversed loads, the tested ultimate loads, the ductility and the reasonable modes of the reinforcement design of two specimens are presented in this paper. Test results revealed that the ultimate loads and the ductility of the specimen with anti-punching shear bar is higher than that of the corresponding specimen. Based on the experimental studies, the simplified mechanic model is proposed. The calculated results correlate well with the results of experiment.