基桩缺陷逐步能量恢复递推定量分析

通过大量正演计算,对不同桩周土条件下缺陷程度与时域速度响应波形中入射波波幅与反射波波幅的比值进行了相关性分析,拟合出桩侧土为粘土、砂土、粉土条件下桩径变化程度与波幅比之间的关系式。通过理论分析,在基桩存在多缺陷时,导出了缩颈与扩颈对下一个缺陷引起的反射波幅值的影响系数,进而,提出了逐步能量恢复递推缺陷程度的理论与方法,在时间域中,实现了基桩存在多缺陷时的低应变动测缺陷量化分析。模型桩试验分析结果表明,缺陷量化分析方法可取得显著效果。

Quantitative recurrence analysis to determine defects of piles by energy recovery method

Through a great deal of calculation, the relationship between defect degree and ratio of the incidence wave amplitude to the refection wave amplitude is studied. The influence of the characteristics of the soil around piles is taken into account. By means of theoretical analysis, the influence coefficients of a reduced neck defect or a expanded neck defect to the next one are derived in the condition ofmulti-defect pile.The theory and method for determining the defect's degree to the foundation pile with more defects are discussed, in which the method of regaining the energy of elastic wave and the recurrence formula are developed.In time domain, the quantitative analysis of defects for multi-defect pile is realized by low strain dynamic test. At last, model pile test is carried out to prove the accuracy of quantitative analysis theory.