Soil-Foundation problem

[dks]

I have created a half model of a rigid ring foundation on PDMY/PIMY soil and assigned foundation as a elastic isotropic material with high value of elasticity. For both soil and foundation I used bbar brick element. All boundary condition of soil are OK as per my knowledge and the soil and foundation share common nodes, So i kept their bc's free along all directions. My objective was to see strain -displacement profile of soil under combined effect of gravity and concentrated static vertical loadings . But as per the results, I am getting abnormally high displacements at the top with the footing completely settling down into the soil and the soil doesn't show any strain variation along the vertical direction. Before this I tried analyzing with only gravity loading and without footing and got satisfactory results but not his time.Can anyone Please say where I am going wrong? For check purpose I even tried to see variation in results by decreasing the concentrated load, but still the result was same.