Isolation Prospects of Geosynthetics Reinforced Soil Beds Subjected to Vibration Loading: Experimental and Analytical Studies

The study discusses the potential use of geosynthetics in isolating the ground vibration emanated from the vertical mode dynamic excitation. A field study was conducted to investigate the screening efficacy of reinforced foundation beds. In the field study, vibration was generated using a mechanical oscillator. Four different cases, namely, unreinforced, single layer geogrid, two layers of geogrid, and geocell reinforced cases were considered. The isolation efficacy was studied in terms of peak particle velocity and amplitude reduction ratio. The resonance response of different reinforced conditions was studied by varying the dynamic force, and frequency of the excitation. The effectiveness of the reinforced soil system was examined by comparing the performance of the reinforced system with the unreinforced system. From the field test results, a significant reduction in ground vibration was observed in the presence of geosynthetics. Maximum reduction was observed in the case of geocell reinforced condition as compared to other cases. In the presence of geocell, peak particle velocity and resonant amplitude were reduced by 48% and 61% respectively, as compared to the unreinforced condition. Similarly, 98% improvement in the stiffness of the foundation bed was observed in the presence of geocells. Further, the dynamic response obtained from the field study was compared with the mass spring dashpot analogy. The dynamic response predicted from the analytical study has shown reasonable agreement with the field test results. From the analytical comparison, 2.6 times improvement in the damping ratio of the foundation bed was noticed due to the inclusion of geocell reinforcement.