Evaluation of post tension runway plate as retrofitting simulated with compression in-plane force in numerical approach / Muhammad Daffa Fachrur Reza, Sofia W Alisjahbana and Muhammad Nuzulul Furqan

The swelling of soil can result from fluctuations in its moisture content, causing it to expand and contract. To mitigate this, structures in direct contact with the soil may require retrofitting. Post-tensioning is one such method that can enhance the stiffness of the structure without altering its properties, thereby helping to prevent damage from expansive soil. This research presents a novel methodology for the design of retrofitting runway pavements using post-tension plates, employing a numerical approach that considers various influencing factors. The methodology integrates the use of differential and Kerr foundation equations, employing the Levy method to ascertain the deflection of the plate structure. Soil parameters are derived from soil sampling and laboratory tests, while loads are determined based on prior research findings and governmental regulations. The findings of the study indicate that the thickness of the plate structure influences its deflection, as greater thickness results in increased stiffness within the structure. Increasing the thickness of the plate enhances stiffness and diminishes deflection. Regarding the direction of post-tensioning, employing tension in both directions proves most effective, resulting in a reduction of deflection by 22.11%. However, this model demands higher costs compared to others due to the increased requirement for tendon post-tensioning. As an alternative, aligning the direction of post-tensioning with the direction of load movement can lead to a reduction of 15.14% in plate deflection, while incurring lower costs compared to applying post-tensioning in both directions.