【摘要】 通过对干旱地区黄土中扩底桩的抗拔试验 ,测试了扩底桩在上拔荷载、水平荷载作用下的上拔位移和水平位移以及位移与荷载的关系。研究了极限上拔承载力和抗拔桩的破坏机理。在相同条件下 ,增加扩大端的高度对提高桩的极限上拔承载力是有效的 ,破坏机理为土的减压软化和损伤软化的渐进性破坏。提出了极限上拔承载力的理论计算模式 ,并与实测资料进行了对比 ,理论计算结果与实测值是吻合的更多还原

【Abstract】 The field prototype tests have been carried out for under\|reamed piles bearing uplift loading in the loess of drought area.In these tests,uplift displacement and horizontal displacement of under\|reamed piles bearing uplift loading and horizontal loading,displacement of surface layer soil,relationship of loading and displacement were measured.The ultimate uplift bearing capacity,failure mechanism of piles were studied.It is very effective on improving ultimate uplift bearing capacity of pile to raise height of belled\|out section of under\|reamed piles.The failure mechanism of the pile is a gradual failure due to damage softening and reduction pressure softening of the soil.A theoretical model is proposed to calculate the ultimate uplift bearing capacity in the loess,and comparing the calculation results with the test data,both are basically similar,which shows to have chosen correct calculation pattern.更多还原