Abstract
<title>Abstract</title> <p>This study evaluates the load-settlement behaviour of a square footing resting on geocell-reinforced Rubber Sand Mixtures (RSMs) through reduced-scale model tests, focusing on the reinforcing effect of the geocell and the influence of size of rubber granule. The compressible rubber granules in RSM were found to reduce the bearing pressure and increase the settlement of the footing. When rubber granules similar in size to sand were incorporated, there was a notable reduction in bearing pressure and increased settlement compared to RSM composed of rubber granules larger than sand. Subsequently, the behaviour of RSM with geocell as reinforcement was examined and found that geocell reinforcement increased bearing pressure and reduced settlement of RSM due to passive confinement provided by the cell walls. This improvement was particularly significant for larger rubber granules, attributed to better interlocking of rubber particles within the geocell apertures. Parameters such as placement depth and height of geocell reinforcement yielded optimal values concerning the bearing pressure ratio (BPR) of the footing. Increasing the placement depth of the geocell from the footing and reducing the width of the geocell to less than the width of RSM resulted in a considerable reduction in BPR. The bearing pressure of RSM with smaller rubber granules was effectively enhanced solely through the geocell–geogrid combination, which restricted the downward movement of rubber particles by mobilizing additional tension in the geogrid. These findings highlight the effectiveness of geocell reinforcement on RSM and the influence of the particle size of granulated rubber on the reinforcement elements.</p>