基桩低应变反射波法典型时域信号识别技术研究

结合基桩完整性PIT现场对比试验,对低应变反射波法现场测试和室内分析出现的典型疑难检测信号进行了分析研究.结果表明,传感器粘贴好坏、盲区内浅部缺陷的存在及深度变化、长桩段扩颈桩的存在、桩周土层软硬夹层的组合特性及嵌岩桩桩底岩土特性变化等在低应变反射波法检测曲线上均具有典型的反射信号,正确认识这些反射信号的特征,可以保证低应变反射波法具有较好的基桩完整性检测效果.

Low-strain reflected wave method for identification of typical time-domain signals of foundation piles

In combination with PIT field comparative tests on the integrity of foundation piles,a study was performed on typical doubt signals in field test and laboratory analysis with the low-strain reflected wave method.The result shows that typical reflected signals occur in the detection curve,which can reflect the fixing effect of sensors,the shallow defects and their depth variation in blind zone,the existence of bulbs in long section of piles,the combination characteristics of soft and hard soil strata in pile surrounding soil,and geotechnical characteristics at the toe of embedded piles.Therefore,correct identification of these reflected signals is helpful to obtain satisfactory result from integrity testing of foundation piles with the low-strain reflected wave method.