双叶片螺旋钢桩抗压承载力试验研究及工程应用

Experimental Study and Engineering Application of Compressive Bearing Capacity of Double-bladed Spiral Steel Pile

通过现场加载试验研究,探讨了桩长、桩径、叶片面积和叶片间距4个因素对螺旋桩极限抗压承载力的影响,运用Q-S曲线第二拐点法进行极限抗压承载力值的判定。发现螺旋桩极限抗压承载力随着桩长、桩径和叶片面积的增大而增大,但叶片面积过大时,由于叶片与桩身钢管连接处的弯矩过大,加载中焊接处容易脱开,导致极限抗压承载力不增反减;随着叶片间距的增大,极限抗压承载力先增大后减小;将试验中得到的结论成功的运用到了实际的工程中,并取得了良好的效果,从而可以为以后类似的工程提供借鉴意义。

Through the field loading test research,the influences of pile length,pile diameter,blade area and blade spacing on the ultimate compressive bearing capacity of the screw pile were discussed.The Q-S curve second inflection point method was used to determine the ultimate compressive bearing capacity value.It is found that the ultimate compressive bearing capacity of the screw pile increases with the increase of the pile length,the pile diameter and the blade area.However,when the blade area is too large,the bending moment at the joint between the blade and the pile steel tube is too large.It is easy to disengage,resulting in the ultimate compressive bearing capacity decreases;as the blade spacing increases,the ultimate compressive bearing capacity increases first and then decreases;the conclusions obtained in the test are successfully applied to the actual project and achieved good results,which can provide reference for similar projects in the future.