chapter  98
The development of “Push-heat”, a combined CPT-testing/thermal conductivity measurement system
ByG.T. de Vries, R. Usbeck
Pages 5

In design of offshore powercables, thermal characteristics of the soil in which the future cable will be located are needed to calculate and predict cable capacity and lifetime. Traditionally, thermal characteristics were measured in the laboratory, on samples obtained with various drilling and coring techniques. Unfortunately, for various reasons, results of laboratory testing are not always consistent. This necessitated the design of a reliable system to measure thermal characteristics, both in the laboratory and in-situ. Older in-situ measurement techniques have mainly focussed on deployment in soft soil and deep water. For use in coastal environments, with complicated soil profiles and soil types more resilient to penetration, these older systems have only limited practical use. Early development of a system combining vibrocoring with in situ thermal conductivity measurement has proved reasonably succesfull but in some soil types still rendered anomalous results. This paper discusses the development of a new measurement system which combines traditional CPT pushing- and measurement technology with an existing well established in-situ thermal measurement technique. Some initial measurement results are presented.