摘要:
对埋入式钢柱脚的设计方法进行了研究,分析了其传力的机理。指出因为栓钉的存在,钢柱必然传递一部分轴力给外包混凝土柱,利用组合柱理论对外包混凝土的压力进行了计算,得到了简单的公式,通过算例发现,传递到外包混凝土的轴力是总轴力的25%~35%。根据这个传递比例,提出栓钉验算和柱脚底板计算的方法。同时,根据混凝土埋入式钢柱脚的弯矩和剪力的传递,介绍了混凝土埋入式钢柱脚抗弯强度的计算公式,对于边柱和角柱,提出了沿整个埋入深度设置水平U形钢筋的要求和计算方法。对于竖向抗冲切不足的问题,介绍了设置水平短钢梁将竖向力扩散到更大范围的方法。
Abstract:
A theoretical study is carried out on the current design approach of embedded steel column bases.The load transfer within embedded bases is analyzed.Because of the studs,part of the axial load is transferred from steel to foundation concrete.An analytical solution is presented for the axial load in the concrete.Through calculated examples it is found that the axial force in the concrete is 25%~35% of the total axial force of the column.Based on this finding,the design methods of shear stud and the column base plate are proposed.Based on the shear and bending moment transfer of the embedded steel column bases,the strength check is proposed,and for side columns and corner columns,horizontal U-rebars are proposed to prevent horizontal punch shear failure of concrete,method for determining the area of the U-rebars is presented.Embedded steel column bases have inadequate vertical punch shear strength below.It is presented a method for avoiding this punch shear failure by adding horizontal short steel beams at the base.