The benefits of combining test methods and knowledge from different fields of expertise

Paper in proceeding, 2015

The geothermal properties of soil are critical both for the design and the maintenance of high-voltage power cables. A correct determination of the properties will ensure that a cost-effective cable without unnecessary energy losses can be chosen. It will also strongly influence that costly damages to the cable due to over-heating do not occur. Hence it is important to find an investigation strategy that is practical, economical and gives reliable results. This paper presents the results from a site-investigation project performed during 2013 in Dar es Salaam. The aim of the project was to determine the geothermal properties that should be considered for the design of new underground high-voltage cables, planned for improving power supply in Dar es Salaam. The paper presents an approach that combines information of the geological history with test results from both geothermal testing and classical soil investigation. The correlation between soil type, water content, density and anticipated geothermal properties is discussed. The obtained differences in geothermal properties determined in laboratory and field are also considered.