桩土相互作用阻尼的试验研究

依据桩土系统受瞬态力作用下波动阻尼方程定义桩侧土阻尼系数,通过模型桩室内试验,模拟真实的桩土系统边界条件,在桩顶进行小应变反射波测试,得到桩底反射波与入射波幅值比随桩周应力的增大成线性减小。利用桩身应力波衰减规律,进一步得出桩侧土阻尼系数随着桩周土应力的增大而成指数增大,最终得到在不同含水状态下砂土、粉土、粘土三种土中桩侧土阻尼系数与桩周应力的相关模型。

Study on Pile-soil Interaction Damping by In-situ Test

Based on fluctuation-damping function of pile-soil system under instantaneous load,the damping coefficient was defined.Then,indoor model pile test was made and real boundary condition of pile-soil system was simulated in the test.The conclusion that amplitude ratio between reflective wave of bottom and incident wave declines linearly with lateral stress increasing was made.And according to attenuating regularity of stress wave in pile,the result that damping coefficient increases exponentially with lateral stress increasing was made too.Finally,correlative model between stress and damping coefficient in sand,silt and clay were obtained in this paper.