SOIL FABRIC CHANGES DUE TO THE INSTALLATION OF CERAMIC SUCTION CUPS

Samples from different sites containing ceramic suction cups with the surrounding soil were taken. After embedding and hardening in polyester resin polished blocks and thin sections were prepared. Soil zones up to 2 cm wide around the cups show up as more or less influenced. Former interaggregate or channel voids disappear. Clay coatings or infillings are smeared over into reoriented streaks. These features appear in dependence upon the predominant grain size distribution. In medium to fine grained soils the said zone is superimposed by a concentric system of fine cracks forming scaly shaped lamellae in perpendicular orientation around the cups. In coarse grained soils the extent of displacement and regrouping of sand grains is hardly visible. Piercing through a banded fabric (B(t)-Band), a striking side and downward displacement of grains became obvious. In all cases a flushed silt or fine sand sludge works well to improve the soil/cup contact.