DETERMINATION OF THE STRESS–STRAIN STATE OF THE RIGID PAVEMENT STRUCTURE OF AN AIRFIELD ACCESS ROAD

The article presents a comprehensive study of the stress–strain state of a rigid pavement structure of an airport taxiway, taking into account the three-dimensional nature of aircraft wheel loading and the long-term operational conditions of the pavement system. The relevance of the research is driven by the growing need to ensure high durability and structural reliability of airfield pavements that operate under intensive cyclic loading from modern aircraft and must provide safe and uninterrupted functioning throughout the designated service life. The study describes the material characteristics of the three-layer airfield pavement system and determines the load parameters applied by the main landing gear of the reference aircraft. Bending moments in the upper and lower concrete layers are calculated, and compliance with strength conditions is assessed for a 20-year operation period at an intensity of five aircraft movements per day. The geotechnical and hydrogeological conditions of the construction site are analyzed, including the classification of engineering-geological complexity and the potential impact of natural processes on pavement performance. The bearing capacity of the pavement structure is evaluated using the FAARFIELD 2.1.1 software based on the method of aircraft and pavement classification parameters. To verify and refine the obtained results, a finite element model consisting of nine concrete slabs with expansion joints is developed in LIRA-SAPR. The model allows visualization of vertical and horizontal displacements and stress distribution under aircraft loading. The maximum vertical displacement of the structure is 0.941 mm, horizontal displacement is 0.216 mm, and peak vertical stresses reach 39.8 t/m², indicating that the structure operates within safe limits. Based on the numerical calculations, recommended layer thicknesses for two aircraft mass scenarios –maximum takeoff weight and empty weight – are proposed. The optimal thickness of the upper concrete layer (C25/30) is 298 mm and 158 mm respectively, while the lower lean-concrete layer (C8/10) is optimized to 150 mm instead of previously accepted 300 mm. These results confirm sufficient bearing capacity and structural effectiveness of the designed pavement system. The findings contribute to improving the design of rigid airfield pavements and support the selection of rational material and structural solutions. Future research should focus on assessing pavement behavior under varying climatic impacts, freeze–thaw effects, moisture sensitivity, and interaction with heterogeneous soil foundations, as well as modeling pavement response under increased traffic intensity from modern aircraft fleets.