6. Conclusion
The purpose of this study was to propose a new dual beam model and obtain the exact solution for the analysis of the geosynthetic reinforced granular fill with an upper pavement structure resting on an elastic foundation. The pavement structure was assumed to be an Euler–Bernoulli beam and the geosynthetic reinforced granular fill was simulated as a reinforced Timoshenko beam that could consider the shear and flexural deformations. The foundation soil was modeled by a Pasternak model. The model was verified by comparing the results with FE model and other two simplified beam-foundation models. It was found that the present dual beam model was obviously superior than the two simplified models and the pavement settlement results were in good agreement with the FE model. It was found that the stiffness and shear modulus of the foundation soil had significant influences on the settlement and bending moment of this dual beam system, such that when these two parameters expanded, total settlement would decrease accordingly and the different rate of settlement of the upper pavement and geosynthetic layer would also decrease. It was also noted that negative forces appeared within the geosynthetic reinforcement due to the limitations of the Timoshenko beam theory. In the future, other FSDTs and HSDTs can be considered to simulate the beam-foundation system.
