Influence of Geocell Reinforcement on Bearing Capacity of Low-Volume Roads

This study examined the working principles of the geocell reinforcement in low-volume roads through laboratory testing and finite-element modeling (FEM). A steel box of 1.5 m × 1.2 m × 0.9 m (5 ft. × 4 ft. × 3 ft.) was fabricated to accommodate multiple pavement layers. A quarter of the laboratory test box was modeled using commercially available FEM software. A low modulus base and subgrade materials were selected, and the base layer was reinforced with 152 mm (6 in.) high geocell to evaluate the benefits of geocell reinforcement. A dynamic cyclic load of 551 kPa (80 psi) was applied for a set number of cycles (20,000 in the laboratory and 100 during computer simulations). The laboratory test setup was instrumented to record the responses of the material under dynamic cyclic loading. Since the transducers generated substantial data points along with associated signal noise, a set of procedures were incorporated to minimize the electronic noise and reduce the data size. The laboratory test results indicated that the geocell-reinforced sections experienced lower vertical stresses imparted on top of the subgrade nearly by 30% in comparison to unreinforced sections. The vertical pressure distribution beneath the geocell layer suggests that the reinforcement is acting like a combination of flexible and rigid pavement. The geocell-reinforced layer performed well even with an increase in stresses from 689 kPa (100 psi) to 827 kPa (120 psi). Although similar hoop strains trends were observed, the hoop strains estimated from FEM were different than the ones measured in the laboratory.