Worldwide, waste tires are being discarded in landfills at a huge environmental cost, therefore, their use as a three-dimensional reinforcement material is a wise solution to reduce their environmental impact, and fire risk in the case of shredded tires. In this research a series of experimental model tests of embankments reinforced with Geocell and tires were conducted to compare the performance of these types of reinforcement. The models tested had different Geocell embedment depths, number of Geocell layers, vertical spacing between Geocell layers and density or soil stiffness. Testing consisted of applying pressure at the crest of the embankment and monitoring the pressure distribution, as well as the vertical and horizontal deformations inside of the embankment. The results suggested that when compared with unreinforced embankments, reinforced embankments effectively improve the bearing capacity, thereby, reducing vertical and lateral displacements. This study also showed that an optimal embedment depth and spacing between Geocell reinforcement layers can further improve the slope performance. Comparisons between Geocell reinforced embankments and waste tire reinforced embankments, showed that waste tire reinforcement has a superior performance over the Geocell-reinforced embankments. This difference in performance between the two types of reinforcement is more apparent if the embankment backfill has lower stiffness. i.e. lower density.

To investigate the effects of freeze-thaw cycles on performance of geosynthetic reinforced earth retaining walls, two model tests of 1.0 m-high geogrid-reinforced retaining (GRR) walls without and with the loading plate and 10 kPa surcharge were carried out under five freeze-thaw cycles. In each freeze-thaw cycle, both freeze-temperature of −15°C and thaw-temperature of 35°C were maintained for 12 h alternatively. The test results showed that the temperature field and mechanical performance of the GRR walls significantly depended on the ambient temperature and the number of the freeze-thaw cycles. The effect of ambient temperature on the temperature field in the model GRR walls gradually reduced with the distance from boundary increase, which is more obvious for the model GRR wall with the loading plate. The settlement at the top of the model walls and the lateral displacement increased with the increase of the number of freeze-thaw cycles, especially for the model wall with a surcharge. The additional earth pressures and geogrid strains in the model GRR walls significantly varied with the ambient temperature. The test results also showed that the performance change of GRR walls mainly happened in the initial two to three freeze-thaw cycles.

No abstract

No abstract