预应力钢骨混凝土支托刚架试验研究

Experimental study on the triangular bracket of PSRC

通过对2榀比例为1∶4的结构模型室内静力试验,研究重庆国际大厦工程中预应力钢骨混凝土(prestressed steel reinforced concrete,PSRC)巨型三角形支托刚架的受力性能及破坏形态等设计问题.结果表明,参照普通预应力构件的计算方法,PSRC构件的高含钢率对短期预应力建立无不利影响;平截面假定对普通钢骨混凝土构件和PSRC构件都成立;建议对支托刚架的承载力极限状态考虑两道安全防线;拉杆设计应偏于安全以开裂作为首要控制目标;上部节点区所配斜向箍筋在出现裂缝后发挥明显作用,应同时作为受拉钢筋和箍筋来对待,其他节点区的水平箍筋可按构造要求配置.

The bearing performances and failure features of the prestressed steel reinforced concrete （PSRC） triangle brackets of the Chongqing International Edifice were investigated by the static experiments on two 1：4 scale models. The results calculated by the method for ordinary prestressed concrete show that the high steel ratio of the PSRC elements has no negative effects on short-term prestressed establishment of PSRC. The plane-section assumption is tenable for both steel reinforced concrete and PSRC elements. Two secure fortification lines should be considered for the carrying capacity ultimate state of the triangle bracket. The first aim of design is to control the cracking of the tensile rod for more safety of structure. Since the hooped reinforcements in upper joints play a positive role after cracking, they should be considered as tensile and hooped reinforcement. The hooped reinforcements in other joints may be arranged according to the structural requirement.