循环荷载下砂土地区桩基础抗拔承载力研究

Research on Uplift Bearing Capacity of Pile Foundation in Sandy Soil Area Under Cyclic Load

为分析循环荷载下砂土地区桩基础抗拔承载特性,文中就循环荷载作用下桩基础的承载性能开展试验,分析埋深率、密实度以及单双向循环对桩基础承载性能的影响。结果表明,高循环荷载比下,桩基累积沉降量随着荷载作用次数的增加先快速增加后趋于稳定;双向循环作用条件下,桩基累积沉降量随着荷载作用次数的增加呈现先快速后缓慢增加、最后趋于稳定的规律,沉降量稳定在0.3 mm;单向循环荷载条件下,桩基的累积沉降量随着荷载作用次数的增加呈现近似线性增加的趋势,无平台区最大累积沉降量为0.15 mm。整体上,单向循环下的桩基沉降量远低于双向循环下的桩基沉降量。

In order to analyze the uplift bearing characteristics of pile foundation in sandy soil area under cyclic load,the paper conducts tests on the bearing performance of pile foundation under cyclic load,and analyzes the influence of buried depth ratio,compacted degree and single and double circulation on the bearing performance of pile foundation.The results show that under high cyclic load ratio,the accumulated settlement of pile foundation increases rapidly with the increase of load times and then tends to be stable.Under the condition of bidirectional circulation,the cumulative settlement of pile foundation increases rapidly at first,then slowly and finally tends to be stable with the increase of load times,and the settlement is stable at 0.3 mm.Under unidirectional cyclic load,the cumulative settlement of pile foundation shows an approximate linear increase with the increase of load times,and the maximum cumulative settlement in the area without platform is 0.15 mm.On the whole,the pile foundation settlement under unidirectional circulation is much lower than that under bidirectional circulation.