Application of Joint Inversion and Fuzzy C-means Cluster Analysis for Road Pre-investigations

Collated DC resistivity and seismic profiling has become a popular method when doing pre-investigations for infrastructural projects such as roads and tunnels. The motivation behind the usage of two methods is that combined usage of both of these methods can decrease the ambiguity inherent to the individual use of these methods. Several software packages for inversion exist, but possibilities to combine several geophysical methods are limited; research algorithms that have this functionality exists and are evaluated herein. Joint inversion and fuzzy c-means cluster analysis are potentially ways to get the most of the collated data; thus enabling the methods to enforce each other is such a way that interpretation could be improved. These methods were applied on a field dataset from a pre-investigation of a new road. The joint inversion did not result in any major changes in the inverted models for this example, probably due to the very complex geology. The cluster analysis provides an additional tool for interpretation; highlighting for example a dolerite dyke, which can have strong influence on the construction and planning process.