桩基完整性检测中桩身应力波衰减规律及其应用

通过建立桩土系统相互作用模型,对同一桩土刚度比下不同桩侧土阻尼系数时的桩身应力波衰减曲线用最小二乘法进行拟合,得到均质土中桩身任意质点最大波幅和桩顶质点最大波幅比与桩周土阻尼系数和波传播时间的乘积呈负指数关系;成层土中波幅比与各层土的阻尼系数和波传播时间乘积的和呈负指数关系。将其应用于桩身存在单一缺陷时的缺陷程度量化分析模型,建立了较为实用的桩身缺陷程度量化分析模型,并通过工程实例验证。

Attenuation discipline of stress wave in pile and it's application in integrity test

Here pile-soil interacting model was founded. Attenuation curves of stress wave along pile shaft in different surrounding soils of same stiffness was fitted with least square method. And two conclusions were made. One is that in homogeneous soil, there is a negative exponential relationship between ratio of maximum amplitude of a random point at shaft to pile block point. The same relationship between amplitude ratio and sum of product of dampings and times in different layers was founded too in layered soils. Then, above results were used in quantitative analysis of degree of pile defect when there is only one defect in pile shaft. Finally, the validity of the method was verified by testing pile in site.