AN EXPERIMENTAL STUDY ON MODEL STONE COLUMNS

ST. CHRISTOULAS, G. BOUCKOVALAS and CH. GIANNAROS

ABSTRACT: This paper describes the results of two instrumented axial loading tests on large scale model stone columns, constructed similarly to the prototypes with a technique which employs ordinary pile driving equipment. Kaolin was used to simulate natural soil conditions. Pressure cells and electric piezometers were used to monitor lateral stresses and pore pressures respectively, during loading. A factual report of the data and a direct evaluation with respect to the load-deformation response and the mode of failure of the stone columns is provided. Two deformation models are examined: a triaxial specimen expanding laterally under compression and a skin friction pile. Furthermore, a trilinear load-settlement relation is proposed for design purposes, based directly upon the results of the model tests.

Key words: model tests, soil improvement, stone columns (IGC: E2/E4/K6)