Evaluation of the challenges present in the obtaining, processing and interpreting useful data from offshore seismic cone penetration testing

Abstract

The Seismic Cone Penetration Test (SCPT) is an essential tool for establishing in-situ shear wave velocity (𝑣𝑠), which is then used to establish profiles of Small Strain Shear Modulus (𝐺𝑚𝑎𝑥), a direct input parameter to the design of offshore wind turbine foundations. Performance of SCPT offshore presents greater challenges than on land and each offshore site investigation contractor uses their own different non-standard equipment to try to address these challenges. This contributes to the multiple areas of uncertainty in the assessment of wave arrival time and distance, which can result in less reliable data sets. Additionally, a variety of data processing and interpretation methods are used across the industry, the benefits and limitations of which must be understood if one is to specify, plan or undertake such testing. The authors provide a review of methods of acquiring data, the equipment required and the different processing and interpretation methods available, specifically comparing true interval straight ray analyses with pseudo interval true ray path analyses and the different processing steps which can be taken to increase reliability in datasets.

Full Paper