兰州地区旋挖钻孔灌注桩竖向承载力特性试验研究

Experimental research on vertical load bearing behavior of churning driven cast-in-place piles in Lanzhou

通过兰州某交通枢纽项目旋挖钻孔灌注桩静载荷试验与内力测试,分析了该旋挖钻孔灌注桩的荷载传递机理和承载特性。研究表明,桩顶荷载的大部分由桩侧阻力承担,桩端阻力只承担竖向荷载的一小部分;桩侧阻力优先于桩端阻力发挥;荷载-沉降(Q-S)曲线呈缓变型;该试验桩的竖向承载力明显高于一般钻孔灌注桩。

Based on the results of static loading test and stress test for the churning driven cast-in-place pile in a transportation hub project in Lanzhou,the load transferring mechanism and vertical load bearing behavior of the piles were analyzed.The analysis results show that the vertical load is mainly beared by shaft resistance,and a little part of it is beared by tip resistance.The shaft resistance works more preferentially than the tip resistance,and the Q-s curve is slow side form.The ultimate vertical load bearing capacity in this test is obviously bigger than that in average case.