In order to study the vertical cyclic load bearing characteristics of fly ash single-pile composite foundation,laboratory model tests under cyclic load were carried out.By monitoring the changes of pile body and soil,the accumulative settlement of pile top,soil pressure and internal force of pile body were analyzed respectively.The test results show that the accumulative settlement of cyclic pile top presents a rapid increase in the early stage,and the critical value of cyclic load ratio is 0.6.The settlement changes in the later stage are divided into two trends:stability and growth.The soil pressure on the side of the pile mainly affects the soil on the side of the pile,and decreases along both vertical and radial directions,and the vertical attenuation is more obvious.By fitting the strengthening coefficient of pile tip resistance and the weakening coefficient of pile side resistance,a functional equation with reference can be obtained to analyze the changes in the strength of pile tip and pile side resistance under different cycles in actual engineering.The load sharing ratio of pile end/pile side under cyclic load presents a dynamic change.With the increase of cycle period,there will be a reverse overload point in which the load proportion of pile end exceeds the proportion of pile side.The larger the cycle amplitude,the fewer cycles required for the reverse overload point.
关键词
循环荷载/模型试验/复合地基/承载特性/荷载分担比
Key words
cyclic load/model test/composite foundation/bearing characteristics/load sharing ratio
维普
万方数据