循环压拔荷载作用下桩基础模型试验研究OA北大核心CHSSCDCSTPCD

With the continuous rise of large-scale buildings,pile foundation,as one of the commonly used foundation forms in the western region,plays an irreplaceable role in bearing uplift forces.In order to study the bearing characteristics of pile foundation under cyclic loading,single pile pull-out tests,cyclic press-pull tests,and cyclic pull-out tests were conducted on a typical loess foundation in the Loess Plateau area.The study analyzed the distribution patterns of axial displacement at the pile top and the side friction strength of the pile under cyclic compression and pull-out loading paths.It elucidated the variations in pile bearing capacity under different numbers of cycles and varying cyclic loading magnitudes.The results showed that the amplitude of cyclic loading and the number of cycles were important factors affecting the change of axial displacement at the top of the pile,and a weakening coefficient parameter was introduced to quantitatively describe the influence of the number of cycles.The greater the load,the higher the side friction of the pile,but overall.the side friction tended to decrease under cyclic loads.Cyclic compression and pullout loading could reduce the damage to the contact between the pile and soil to a certain extent,resulting in less loss of pile foundation bearing capacity.This study has profound engineering significance for the research on the bearing capacity of pile foundation under vertical cyclic compression and pull-out loads.