Abstract: 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.

Key words: Cross-hole Sonic Logging, Nondefective Factor, Data Collection, Integrity Judgment