低应变动力测桩浅部缺陷测不准的原因分析

文章建立了更符合工程实际的桩土系统瞬态振动计算模型。利用有限差分法计算了完整桩在瞬态轴向激振力作用下的动力响应，计算分析了应用一维理论反演实测曲线会使浅部缺陷变浅的原因。计算结果表明：波在桩中传播的平均波速受各种因素影响不再保持定值-因此传统的反演方法不再能提供可靠的结果；横向惯性效应导致浅部缺陷位置浅判。三维效应的影响与此相反。

The Unpreciseness Analysis of Low-strain Dynamic Pile Examination

Pile-soil transient vibration calculation model that more conforms to engineering practice is established in this paper.FDM is used to calculate dynamic response of the complete pile under transient axial shock excitation.Through calculation it analyzes why the deficiency looks more upper when one-dimensional theory is used to re-display actual measured curves.The result shows that the speed of wave won't be a certain value when it is affected by various factors in its propagation,so the traditional re-display method can't provide reliable data.While transverse inertia effect make the deficiency at the upper part seem more upper,the influence of three-dimensional effect goes to the contrary.