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Land development

During the construction of a storage building it had to be considered that there was almost liquid sludge from former steel production in the subsoil. Because core piling could not penetrate the subsurface hard cinder, geoelectrics had been applied to capture the dispersion of flotation sludge.

Geoelectric profile

Geoelectric profile



A total of 60 geoelectrical profiles with a maximum length of 240 m in an area of more than 5 ha (50,000 square meters) were measured. The distance between single profiles was 5 m and the electrode spacing was 4 m to reach a maximum interpretation depth of about 15 m.


After finishing the field study the data of each profile were used to calculate depth slices of electric resistivity. In a next step a 3D-model of the sludge distribution had been calculated. Thereupon, two core piling verified the results by agreeing almost perfectly in sludge thickness, as well as in actual depth.


Depth slice of electric resistances in a depth of 7 m

Depth slice of electric resistances in a depth of 7 m



3D-model of the flotation sludges

3D-model of the flotation sludges