Damage detection of concrete piles subject to typical damage types based on stress wave measurement using embedded smart aggregates transducers

Concrete piles are the most common types of foundation structures. Pile damages, such as fractures, cracks, mud intrusion and secondary concrete pouring, are the leading causes of pile structural failure, which may directly result in casualties and economic loss. It is desirable to develop a monitoring system that can detect these pile damages. In this paper, embedded piezoceramic-based smart aggregates transducers along with the active sensing approach are developed to detect common types of pile damages, including crack, partial mud intrusion, secondary pouring, and full mud intrusion, based stress wave measurement. With the active sensing approach, one smart aggregate is used as an actuator to generate a stress wave that will propagate along the pile, and other smart aggregate(s) will measure the propagating wave. All damages, which introduce new interfaces and discontinuities, attenuate the stress wave propagation. The attenuations of the stress waves based on different pile damages were compared by the received sensor signal in time domain. A wavelet packet-based energy analysis was used to develop an energy index to assist the detection of damages. Experimental results demonstrated the feasibility that the proposed approach can detect all four types of common damages associated with concrete piles.