Total engineering geology approach applied to motorway construction and widening in the Netherlands: Part II: Pilot site in tidal deposits

The total engineering geology approach is applied to a roadway pilot project in the tidal deposits of the Western Netherlands. Its benefit as compared to the conventional geotechnical site investigation is demonstrated. Combining laser scanner altimetry data that is readily available to low cost GEM-2 electromagnetic surveys, allows for the refinement of the local geological model. Small and large scale heterogeneities have been detected in this study. Their existence has been confirmed by a line of closely spaced CPTs. On the basis of laser altimetry and GEM-2 signature, the identified heterogeneities are classified. Only a limited set of heterogeneities representative of the different classes requires a further detailed investigation. Aspects of feasibility, accuracy, and cost-effectiveness have a need for further research.