ANALYSIS OF THE INTERACTION BETWEEN GEOGRID-REINFORCED SOIL AND SUBSIDING SOILS

Abstract

Over two-thirds of Kazakhstan’s territory consists of subsiding soils, posing a significant risk of structural failure for new construction. This article aims to address the challenge of construction on subsiding soils by evaluating the effectiveness of geosynthetic reinforcement in a real-life example: a footbridge on the Kaskelen-Uzynagash road. The construction site involved problematic light brown loams with a low deformation modulus (E_def = 2.9 MPa). In order to reinforce the ground, a crushed stone cushion (fraction 20-40 mm) reinforced with Tensar TriAx TX170 geogrids (aperture size 40 mm) was used, and the obtained data show that the geogrid locks with the crushed stone to form a stiff composite platform. This method effectively doubled the bearing capacity (by 2.0–2.5 times) and raised the equivalent elastic modulus by 6–15%. We recorded a 50% drop in substrate deformation and found that residual deformation accumulated 1.3–1.4 times more slowly. Additionally, shear stresses decreased by 25-80%, leading to much more uniform load distribution. These results prove that geogrid reinforcement is a practical and highly efficient way to control the stress-strain state in collapsible soil environments.