Abstract: This paper presents experimental data obtained during the construction and loading test of an oil tank , which was constructed by SINOPEC Maoming Petrochemical Company. Currently, this oil tank is the largest in China. The tank was founded on loose sand improved with stone columns. Pressure cell and piezometers were used to monitor soil stresses and pore pressures respectively. At the same time the deformation of the soil foundation was observed. The obtained result was analyzed thoroughly.