Abstract: A model study was performed on the effect of tapered rigid inclusion in the cement mixed columns as a composite ground in the soil improvement applications. A model cement mixed soil column was prepared in a PVC pipe by layers. One instrumented cylindrical aluminum rod and two instrumented tapered aluminum rods with different taper angles were statically pressed in with a hydraulic jack. The strain in the rigid inclusions, vertical displacement of soils surrounding the rods and the rod axial resistance were measured. The results indicate that, under the lateral compression action of the soil in the penetration of the tapered rods, the surrounding soils formed the tapered shape accordingly. During the tapered rod penetration, no soil heaving within the monitoring radius of 10 centimeters. The observed minimum settlement of 1 millimeter had a distance of 10 centimeters to the center of the rigid inclusion. The penetration of the tapered rod increased with the penetration depth. 

Key words: Tapered Inclusions, Static Piling, Strain in the Pile, Vertical Displacement