薄壁方钢管砂卵石组合柱轴压极限承载力试验研究

Experimental Study on the Ultimate Bearing Capacity of Thin-walled Square Steel Tube Sand Gravel Composite Columns to Axial Loads

保持砂卵石压实系数在建议大于87.7%的范围[1],以方钢管壁厚和长细比为主要变化参数,对10根薄壁方钢管砂卵石柱的轴压静力性能进行试验研究,并通过试验对比分析试件的破坏形态、极限承载力、荷载-位移曲线以及荷载-应变曲线等数据。试验结果表明:1壁厚为2mm试件的承载力较低,钢材未达到屈服强度,管壁就已经发生局部屈曲,钢材性能未得到充分发挥;壁厚为4mm的试件的承载力达到500kN^600kN,钢材达到屈服强度,建议钢管壁厚至少为3mm;2试件的极限承载力随长细比增大而降低;3相对于空心方钢管柱,试件的极限承载力有所增加;壁厚从2mm增到4mm,砂卵石与钢管壁的相互作用更加显著。

Keeping the compacting factor of sandy pebble greater than the suggested range of 87.7% , using the thickness and slenderness ratios as main parameters, the static experimental study on the mechanical property of ten sandy-pebble-filled thin-walled square steel tubular columns under axis pressures is carried out, and the failure characteristics, load-carrying capacity, the load-strain curves and the load-compression displacement curves of the test specimen are comparatively analyzed. The results indicate that： （1）the thickness of 2 mm specimens＇ bearing capacity is lower, local buckling of tube wall occurs prior to steel yielding, while the thickness of 4 mm specimens＇ bearing capacity is higher, so the wall thickness of 3 mm steel tube is suggested at least; （2）the ultimate bearing capacity of the specimens decrease with the increase of slenderness ratio; （3）compared with the hollow steel tube column, the ultimate bearing capacity of the specimens increase, the thickness of wall increases from 2 mm to 4 mm and the interaction of sandy pebble and steel tube wall are more significant.