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Geotextile encased columns for reducing the heave potential of expansive clays

Geotextile encased columns (GEC) includes a high strength, creep resistant, seamless, tubular woven geotextile that confines the compacted sand or gravel column thereby providing easy con-structability and high bearing capacity even in extremely soft soil. GEC can resist the radial horizontal stresses in the columns through the circumferential resistance of the high strength geotextile. GEC can al-so act as large diameter vertical drains, which can speed up the settlement and consolidation process. The capacity of GEC to reduce the heave potential of expansive clays is shown. This problem has not found a proper solution so far. A case history is presented, where the capacities of GEC have been used to solve very difficult geotechnical problems created by the heave of expansive clay in an electrical station in cen-tral Italy. Design, installation procedures, and the results of monitoring programs are presented, showing that GEC can be used in one of the most difficult geotechnical applications.