Experimental implementation of multichannel surface wave analysis of a concrete pipe along lengthwise direction

Abstract

This is a follow up to our previous paper (Jaganathan, 2019) where the multichannel surface wave (MASW) analysis of a concrete pipe segment was proposed. In that paper, this method was experimentally demonstrated using elastic waves that propagate along the circumferential direction of a reinforced concrete pipe. This paper presents the experimental implementation using waves that propagate along the axial direction of the pipe and its elastic properties along a particular lengthwise cross-section are determined. A numerical validation is conducted by feeding the extracted material properties into a finite element based elastodynamic model. The P-wave velocity estimated by the multichannel approach is used in conjunction with the impact echo analysis to verify wall thickness. In the second half of the paper, multichannel analysis of buried pipes are discussed. Specifically, the effect of soil cover on the dispersion images obtained from the pipe wall is evaluated. Synthetic records are used for this purpose. Dispersion images of a buried pipe for several soil types are generated and compared.