The Fourth James K. Mitchell Lecture: The CPT in offshore soil investigations - a historic perspective

Abstract

For the last 40 years, the CPT has played a key role in offshore soil investigations, mainly in connection with oil and gas development, but also for other purposes. The offshore application of CPT has been an important factor with regards to development of equipment, data processing and interpretation. Each of the following aspects are discussed in terms of historic development, present status and future challenges:

- Deployment method and equipment.

- Penetrometer design and construction.

- Data acquisition, processing and quality control.

- Standards and guidelines.

- Interpretation of results and application in foundation design.

It is shown that these developments have greatly enhanced the reliability and applicability of the use of the CPT in soil investigations and design. However, there are still important challenges to be faced in the future

Keywords:

• CPT
• offshore
• investigation
• history

Acknowledgements

The author is greatly honoured to be asked by the CPT-10 organizing committee and TC-10 of the International Society of Soil Mechanics and Geotechnical Engineering to present the 4th James K. Mitchell lecture. The author would like to acknowledge a large number of colleagues in the offshore soil investigation industry with whom he has had rewarding interaction with over the last four decades – they are too many to be mentioned by name. Several colleagues at NGI have assisted with finalising the paper, including Sook-Ling Lee and Chang Shin Gue with figures, Marit Støvne with carefully putting the manuscript together, and Knut H. Andersen and Thomas Langford for reviewing the manuscript and making useful comments for improvements. Vaughan Meyer contributed with the case shown in Figure 29. Reviews by Don DeGroot, Joek Peuchen, Peter K. Robertson, Fernando Danziger and Mike Long have also been very useful.