A variety of complimentary investigative techniques were used across the site including seismic CPT, CPT, sampling boreholes and PS logging to enable comprehensive characterization of the site subsurface soil conditions.
The operations were carried out from two jack up platforms in water depths of between 3m and 11m to a depth of 80 mbsb.
As part of the investigation, high quality PS suspension data was acquired at four sampling borehole locations from the termination depth of approximately 80 mbsb to around 23 to 15 mbsb. Testing and acquisition was carried out at 1m intervals with the BH stabilised with drilling mud to limit/prevent collapse.
The following Robertson Geo equipment and software was utilised for the acquisition and processing of PS logging data:
• PS Logger®
• Surface winch
• Micrologger2 surface interface system
• Winlogger Software installed on a laptop
PS suspension data was acquired in soils, as characterized from the sampling data, as very soft to soft SILT/CLAY overlying Interlayered SAND, SILT and CLAY and the following dynamic soil properties were determined:
• Elastic Moduli
• Shear Moduli
• Poisson’s ratio
• Vp and Vs profiles
Good correlation was found between the sample data and the PS logging data and when assessed with data collected from sampling and testing, BHs across the site contributed to the understanding of cross site subsurface soil conditions.
