A performance comparison of rockfill and geosynthetics for road base under traffic loads

This study presents a full-scale field investigation examining the performance of roads on soft clay soil. The main novelty of the study is the comparison of rockfill-stabilized base layers with geosynthetic (including geocell and geogrid with geotextiles) reinforced bases under real traffic loads. Repeated vehicle loads were conducted by a truck that drove over the road sections 5000 times. After every 1000 passes, surface deformations were measured at various points within each section, thus the rutting values were determined. Besides, the coefficient of subgrade reactions (k_s) for the sections was calculated based on the results from the plate loading tests to interpret behavior at low surface deformation values. The findings were analyzed alongside the improvement factor derived from the k_s value, as well as the traffic benefit ratio and the percentage reduction in settlement calculated from the observed surface deformations of the road to interpret behavior at higher surface deformation levels. The results showed that both rockfill and geosynthetics reduced rutting behavior on the road surface and increased durability. However, it also revealed that geosynthetics controlled rutting more effectively in the long term, while rockfill, although showing strong performance in early deformations, could lose effectiveness at high traffic levels.