A review of cross-hole ultrasonic logging for foundation integrity testing and its evaluation criteria

Abstract

Since the concrete quality of cast in-situ foundation is crucial, the cross-hole ultrasonic logging (CSL) method has become an effective method to assess the homogeneity and integrity of concrete without being limited by the pile length or soil type. Although the testing procedure for CSL is well defined by test standards including ASTM, the interpretation and evaluation criteria of CSL testing results, in contrast, are not well defined and controlled by uniform standards. The current state of practice recorded the application of different rating criteria with different parameters applied for foundations acceptance evaluation. A task force formed by Deep Foundations Institute (DFI) in 2019 has proposed improved rating criteria for CSL results evaluation with the vision of standardized and uniform evaluation criteria in the future. This paper summarizes the current practice of the CSL method and compares the commonly used rating criteria with the currently proposed improved criteria.