Abstract
We studied the characteristic of shear stress for the composite ground assumed the column type, with the unconfined compression test using the agar material and the elaso-plastic finite element analysis employed the elasto-perfect plastic constitutive model. The unconfined compression test in the improved ground ratio 50% using the agar material, indicated the possibility of performing the difference of strength in the constructive direction of the improved column. Also, the elasto-plastic finite element analysis indicated the effect of the difference of strength in the element test level.