Detection of echo signals from discontinuities due to the use of super-resolution procedures for the control of concrete piles by the impact method

Abstract

To control concrete piles, an impact method is used, which allows recording echo signals from the sole of the pile and from reflectors in it. However, the resolution of the measured echo signal is not high enough to confidently separate the reflected pulses and determine their phase. The use of the maximum entropy (ME) method allowed to increase the resolution of the echo signals obtained by the impact method in a concrete pile with a length of 3000 mm by about three times and confidently identify echo signals from artificial reflectors, both in the form of a disk with a thickness of 100 mm and in the form of a parallelepiped with a height of 300 mm. The use of the method of Compressive Sensing (CS) made it possible to increase the resolution of the same echo signals by about ten times. The main problem of the successful application of the ME and CS methods is the determination of the impulse response of a concrete pile upon impact. A method for estimating the pulse response from the processed echo signal is proposed.