Comparison of Underwater MASW, Seismic CPT, and Downhole Methods: Offshore Croatia

Shear wave velocity (V_s) is a key parameter for seismic amplification analyses, and for assessment of liquefaction potential of loose offshore sands. A number of methods are available to measure V_s offshore, including seismic Cone Penetration Testing (CPT), Multichannel Analysis of Surface Waves, and Downhole methods. A marine investigation was carried out offshore Croatia for a new bridge connecting the Croatian mainland to the Peljesac peninsula. During the investigation, direct V_s measurements were taken with the three methods outlined above. This paper presents the data acquisition, processing and results. Advantages and limitations of the three methods used for the survey are discussed.