Construction of roads in soft soils is often associated with design and construction difficulties due to their compressibility nature and weak strength. Road pavements in such areas when subjected to traffic loading that are static and dynamic in nature experience a rapid deterioration of the base material and progressive permanent surface deformation. Both reduce serviceability, and subsequently, the design life of the pavement. In this study, reinforcement geosynthetics (geogrids and geotextiles) were used as reinforcement inclusions within a granular base underlying a soft subgrade having a California Bearing Ratio less than 2 % in a 1.0 m3 steel test box. Bench scale plate load tests (static and cyclic) were conducted on a 305mm diameter circular steel plate on the two-layer system using a Universal Compression Machine. Static loading was applied at a rate of 1.2mm/min. Dynamic sinusoidal load was superimposed atop a static hold down force of 4kN. The dynamic load was linearly increased with an incremental load of 4kN for every 8 cycles at a frequency of 0.2 Hz. For the tests, settlement failure of the composite system was considered at a deformation of 75mm as prescribed for unpaved roads. The results showed that there was a significant improvement in bearing capacity and reduction in settlement accruing from geosynthetic inclusion as shown by the bearing capacity ratio (BCR) of 1.21, 1.29, and 1.63 for geogrid, geotextile, and geogrid-geotextile combinations, respectively. Additionally, a settlement reduction factor (SRF) of 18 % for geogrid, 23 % for geotextile, and 31 % for the geogrid-geotextile combination resulted. There was also an improvement in extended pavement life as depicted by the traffic benefit ratio (TBR) greater than 1 for all reinforced base layers. Comparing geotextile and geogrid reinforced pavements, the results showed that geosynthetic tensile strength is not the governing performance indicator.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.