Investigation of the relationship between the Lamb waves phase velocity and the technical condition of housing and utilities pipelinesA.A. Ibadov, A.E. Kondrat'ev, D.A. Makueva and D.V. SergeevaE3S Web of Conf., 216 (2020) 01080DOI: https://doi.org/10.1051/e3sconf/202021601080