Protection of Buried Pipelines Using a Combination of Geocell and Geogrid Reinforcement: Experimental Studies

This paper describes the laboratory tests on small diameter polyvinyl chloride (PVC) pipes buried in unreinforced and geosynthetic reinforced sand subjected to static loading. The aim of the study was to evaluate the appropriateness of the combination of geocell and geogrid reinforcement system in protecting the underground utilities and buried pipelines. A pipe with external diameter of 75 mm and thickness of 1.4 mm was placed below the footing at different depths ranging from 1B to 2B (where B is the width of the footing). Commercially available Neoweb geocells and biaxial geogrids (SS-20) were used as the reinforcements. Results indicate that the use of the combination of geocell and the geogrid reinforcement system considerably reduces the deformation of the pipe as compared to an unreinforced bed. Above 50% reduction in the pressure and more than 40% reduction in the strain values were observed in the reinforced bed as compared to the unreinforced bed at different depths. Conversely, the performance of the foundation bed was also found to be marginally influenced by the position of the pipe, even in the presence of the relatively stiff reinforcement system.