TESTING OF THE LIME PILE METHOD FOR THE IMPROVEMENT OF SOFT, COHESIVE SUBSOILS AND EMBANKMENTS

ERPROBUNG DER KALKPFAHLMETHODE ZUR VERBESSERUNG VON WEICHEN BINDIGEN UNTERGRUNDBOEDEN UND DAEMMEN

BY MEANS OF THE LIME PILE METHOD DEVELOPED IN 1963 BY THE MATERIALS AND SOILS TESTING CENTRE AT DARMSTADT, IT IS POSSIBLE TO DRY OUT A DEEP, SOFTENED SOIL FORMATION AND TO STABILIZE SOFT LAYERS IN THE SUBSOIL. IN A GRID SHAPED ARRANGEMENT, HOLES 9 CM WIDE ARE DRILLED OR PRESSED INTO THE SOIL AND FILLED WITH QUICK LIME, AND THEN THE SOIL FORMATION IS COMPACTED. INDEPENDENTLY OF THE TESTS IN HESSE, A SIMILAR METHOD WAS USED IN OKLAHOMA, USA; HERE HOWEVER HOLES 15 CM IN DIAMETER WERE FILLED WITH HYDRAULIC LIME. IN ORDER TO ANSWER QUESTIONS WHICH HAVE BEEN RAISED, DESPITE SUCCESSFUL RESULTS, IN PARTICULAR WITH RESPECT TO THE USE OF QUICK LIME OR HYDRAULIC LIME, AND ALSO IN ORDER TO BE ABLE TO OPTIMIZE THE LIME PILE METHOD WITH RESPECT TO COSTS, THE FOLLOWING POINTS ARE TO BE EXAMINED IN SYSTEMATIC CONSTRUCTION SITE TESTS: 1 - THE MOST ECONOMIC PILE DIAMETER 2 - DISTANCE BETWEEN THE PILES IN RELATION TO MOISTURE CONTENT AND SOIL TYPE; 3 - OBSERVATION OF IMPROVEMENT WITH TIME; 4 - TECHNICAL/ECONOMIC APPLICATION OF THE METHOD; 5 - COSTS; 6 LIMITS OF APPLICATION (QUICK LIME, LIME HYDRATE).