Are slurry walls an alround solution for protection barriers against contaminations?

摘要

The growing sensitivity of the society toward the protection of such natural resources as soil and ground water leads to stricter requirements with respect to the reliability of containment measures for contaminated areas. The containment of landfills and hazardous waste sites includes, besides the measures for the establishment of new dumps, also the containment of already existing hazardous waste sites. In the case of new sites it is mainly the vertical barrier, that requires a special solution, since the base barrier is either naturally available as a clayey layer or such a basal lining system can be produced in a conventional way. Dealing with already existing waste sites requires however a complicated geotechnical solution for the production of the basal system, e.g. using grouting techniques. Whilst there are numerous solutions for the production of the vertical barriers as for instance: 1. Two-phase cut-off walls (with plastic concrete or bentonite-soil-backfill) 2. Slurry walls (self hardening supporting fluids) 3. Composite diaphragm walls with synthetic membranes 4. Vibrated slim cut-off walls 5. Deep soil mixing walls (Mixed-in-place) 6. Intersecting pile walls 7. Sheet pile walls 8. Grout curtains (conventional penetration grouting) 9. Jet grouting curtains The variants for the horizontal barriers are rather limited: 10. Natural clay layers 11. Horizontal grout curtains 12. Jet grouting barriers with mineral or chemical binders