Application of surface wave in reinforced concrete invert detection

Abstract

Abstract The thickness of reinforced concrete is an important parameter for tunnel safety, so it is necessary to detect it by non-destructive testing method. We used the multi-channel surface wave (MASW) method to derive velocity of tunnel lining structure in depth and detect thickness of reinforced concrete. The numerical experiment for irregularly dispersive media is conducted to simulate Rayleigh wave. The mode-kissing phenomenon in velocity spectrum is shown, and the modal dispersion curve can be inevitably misinterpreted. The field measurement is carried out on a new construction tunnel site and some Rayleigh wave data are acquired. We compute their velocity spectra. An alternative full velocity spectrum misfit function and a Bayesian inversion scheme are employed to retrieve tunnel lining structure. This study demonstrates that MASW method can effectively retrieve shear velocity of each layer in lining structure and detect the thickness of reinforced concrete inverts.