The impact of centered load of flexible pavement on soft clay with stone column reinforcement

A significant challenge arises when pavements are built on soft clay soils, such as the Gedebage area of Bandung; when centered loads from heavy vehicles are applied, the soft clay soil will experience significant settlement and uneven deformation. This causes the pavement structure to fail, threatening road users' safety and increasing maintenance and repair costs. Often, conventional techniques are not effective enough or have an undesirable environmental impact, so stone columns are used as an alternative to soil reinforcement. This research aims to determine the effect of stone column parameter variation on settlement reduction, bearing capacity, and road stability improvement on soft clay soil, as well as designing flexible pavement thickness using CBR data and average daily traffic surveys using the Pavement Design Manual 2024 method. Stone column diameter variations of 0.7 m, 0.8 m, and 0.9 m and stone column spacing variations of 2 m, 2.1 m, and 2.2 m are given in the finite element numerical analysis with PLAXIS 3D software, where the stone column is soft clay stabilized with palm shell ash and asphalt emulsion. Stone column diameter of 0.8 m and spacing of 2.2 m has a safety factor of 13.65, displacement of 24.42 cm, and bearing capacity of 320.3 kN/m2; it can be concluded that the reinforcement of the stone column can significantly improve the original soil condition.