Pullout Behavior of Sensor-Enabled Geobelts in Weathered Rock Material–Granulated Rubber Mixtures

As lightweight materials, granulated rubber–weathered rock material (WRM) mixtures could be utilized as backfills in geosynthetics reinforcement structures to reduce deformations. However, the deformation behaviour of geosynthetics in granulated rubber–WRM mixtures is not clear. In this paper, pullout tests considering different normal pressures (30 kPa, 50 kPa and 100 kPa) and different granulated rubber contents (10%, 15% and 30%) are performed. Sensor-enable geobelts (SEGB) are employed, which can realize distributed measurements on the strains of SEGB inside soil. Two constitutive models—bilinear model and hyperbolic model are established based on tensile tests and direct shear tests to capture the full stress–strain curves and the interfacial shear responses, respectively, and are employed in the derivation of load transfer equation for pullout process. Numerical results of load transfer equation give distributions of tensile forces, strains, displacements and shear stresses. Test results validate the established constitutive models. Rubber content has an optimal value for the best geobelt–soil interaction. The deformations of geobelts in pullout process start from the front end, but decrease rapidly in soil. Under high normal pressures, the front part of geobelts exhibit quasi-plasticity. The shear stress distributes more uniformly under low normal pressure.