模型桩多波检测的对比研究

Comparative study of multi-wave detection of model piles

文章给出了瞬态激振力下完整桩与浅部缺陷桩的纵波、扭转波及横波实测的桩顶速度响应与数值模拟结果;分析多波检测曲线的特征,结果表明扭转波和纵波桩底反射波相位特征一致,但横波桩底反射波会同时出现同相位和反相位;根据纵波、扭转波及横波在桩土系统传播的定解问题,利用有限差分方法分别求解了3种波的桩顶速度响应,计算结果表明扭转波对浅部缺陷反射更为敏感,但是横波测试的横向尺寸效应受激振力作用时间和桩径比(桩长与桩身直径的比值)的影响要比纵波和扭转波明显。

Subjected to transient longitudinal,torsional and transverse excitation force,the velocity responses and numerical simulation results of longitudinal vibration,torsional vibration and transverse vibration at head of integrate piles and non-integrate piles with a shallow defect are given.By analyzing the characteristics of the multi-wave detection curves,it is indicated that the curves of torsional and longitudinal reflection waves from the bottom of piles share the similar phase characteristics,but it appears both in-phase and opposed phase in transverse reflection wave curves.The definite problems of stress wave propagation in the pile-soil system are solved by the finite difference method respectively,and the simulation results show that the torsional reflection wave is more sensitive to shallow defects,and the transverse wave is more susceptible to the time of excitation force and the ratio of pile length to diameter.