Use of Geocells to Protect Buried Pipelines and Underground Utilities in Soft Clayey Soils

This paper describes the results of laboratory static plate load tests conducted on small diameter PVC (polyvinyl chloride) pipes buried in geocell and geogrid reinforced soft clay bed. The aim of the study was to evaluate the suitability of the combination of geocell and geogrid reinforcement system in protecting the underground utilities and buried pipelines. Commercially available neoweb geocells and biaxial geogrids were used as the reinforcements. A pipe with external diameter 75 mm and thickness 1.4 mm was used in the experiments. Results suggest that the use of the combination of geocell and the geogrid reinforcement system considerably reduces the deformation of the pipe as compared to unreinforced bed. More than 40% reduction in the pressure and more than 60% reduction in the strain in the pipe were observed in the presence of reinforcements as compared to the unreinforced bed. 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. The study revealed that the depth of placement of pipe can be significantly reduced in the presence of the geocell and geogrid. The outcome of the study has the huge financial implications in the large projects, where the pipelines are laid for several hundred kilometers.