型钢对拉螺栓柱托换节点抗剪性能试验研究

Experimental study on shear behavior of column-underpinning-node composed of profiled bar and bolt

针对建筑物整体平移工程中的柱托换 ,提出一种新型柱托换方法 ,该方法将型钢从四周卡入柱身 ,用穿柱螺栓将型钢固定 ,型钢和柱之间填充混凝土 .通过对 4个试件的节点抗剪试验 ,证明这种托换节点在重复竖向荷载作用下具有良好的抗剪能力和延性 .分析认为托换节点的竖向荷载由螺杆的抗剪承载力、新旧混凝土连接界面的抗剪能力和型钢翼缘卡入柱身产生的咬合力共同承担 ,由此给出了型钢对拉螺栓柱托换节点的抗剪承载力计算公式 ,式中通过综合作用系数γ考虑了 3部分的共同作用和相互影响 .文中还建议了新旧混凝土界面抗剪强度按 0 3ft 取值 .最后提供了工程算例 .

A new column-underpinning technique applied to build monolithic movement engineering was put forward. Profiled bar embedded in column, bolt penetrated through column and concrete filled between profiled bar and column compose the underpinning node. The shear experiment of four members shows this column-underpinning-node has better bearing capacity and ductility. The vertical load on the underpinning-node resisted by shear capacity of bolt, new-old concrete interface and profiled bar fringe embedded in column. A formula calculating bearing capacity of the underpinning was advised, and the combined work was calculated by cooperate coefficient γ. The new-old concrete interface shear strength was calculated approximately by 0.3ft was advised. At last, one design example was provided.