Methodological Aspects for Quality Control and Ultrasound Inspection Tests on Retaining Walls

Abstract

Retaining walls are important structures for stabilizing slopes next to buildings. As with any structure, the parts used in retaining walls need to undergo periodic evaluation; as such, it is important to study different inspection techniques and methodologies. Ultrasonic testing has been used for material classification and quality control of the structural parts of various materials, including reinforced concrete. This study aims to evaluate the inspection of a retaining wall made with a lock and load system using ultrasonic pulse velocity. We considered the type of measurement, type of transducer, frequency of the transducer, coupling of the transducer on the inspected part, and distance between the transducers for the indirect measurements. The 45 kHz frequency was the most suitable for inspections before installation. It was found that the exponential surface transducer without coupling holes was the only one that allowed us to distinguish the plates by their velocity. For feasible field tests, the ratio between the indirect and direct velocity was 0.60. A distance of 300 mm between the transducers was the most suitable for indirect tests.