声波透射法桩基检测非缺陷性影响因素

Discussions on the Non-Defective Factors of the Bored Pile Detection by Cross-hole Sonic Logging

结合工程实例对灌注桩桩身混凝土质量声波透射法检测涉及的数据采集及完整性判定过程遇到的非缺陷性因素进行了探讨;声速值的采集受零声时及管距变化的影响,波幅值的采集受仪器系统性能、换能器耦合状态、测距、换能器收发角度等的影响;在注意到这些因素的前提下,测试时要保证换能器探头在理想位置,平稳慢速拉动测绳,且在冬季检测时,注意测距轮打滑现象;数据分析过程,对于焊缝、弯管及声速连续低于界限值等容易造成误判漏判的现象,应进一步进行参数采集,结合多方资料综合考虑。

Based on the actual project case histories,this paper discusses the non-defect factors encountered in the data acquisition and the integrity judgment process in the concrete integrity inspection of bored piles by the Cross-hole Sonic Logging method.The acquisition of the sonic velocity value is affected by the change of‘zero sound＇and the tube spacing.The acquisition of the amplitude value is affected by many factors,such as,the instrument system performance,the transducer coupling status,the pipe distance,the transducer transmit and receive angles.During the test,the operator must ensure that the transducer probes are in the ideal positions and pull the rope smoothly and slowly.Further,the possible slip of wheel that are used for counting distance should be noted in winter seasons.In the data processing,the weld joints,elbow locations and the continuous lower than threshold value of the sonic velocity can easily lead to the misinterpreted results and further data acquisition are necessary.