One of the problems, which would affect airport runways is the settlement of soil. Such settlement would be controlled by enhancing the performance of the soil underneath the airport runway. The composite system consists of graded stone-reinforced soil and reinforcing layers. This system is defined as stone column, which is widely used to improve weak soils as one of the soil stabilization methods due to its simple construction and economic cost. It is used to reduce settlement and enhance soil-bearing capacity. By using such technique, part of the high-compressibility and low-shear strength soil is replaced with coarse filler materials with high-shear strength and extremely low compressibility. In this study, a 3D numerical model of a unit cell is created to examine the impact of changing the controlling parameters in the model, i.e. spacing between columns (S), weak soil cohesion (c), and angle of internal friction for stone column material (φ). It was established that the use of stone columns improves the soil-bearing capacity and reduces settlement, strengthening the stability of airport runways. The efficiency of the system is improved by increasing the column material's internal friction angle and the cohesion of the surrounding soil. The ultimate bearing capacity of soil without SC and SC-soil systems were 150 kPa, and 460 kPa, respectively, which illustrates that the bearing capacity was increased by 306.7%.