Vibration isolation using 3D cellular confinement system: A numerical investigation

This paper investigates numerically the potential use of cellular confinement systems in isolating the machine induced vibrations. The numerical analysis was carried out using the three dimensional explicit finite difference package FLAC(3D). Primarily, the numerical model was validated with the results of field resonance tests, performed on the foundation beds reinforced with and without cellular confinement systems. The 3D cellular confinement was simulated using two techniques, namely, Equivalent Composite Approach (ECA), and Honeycomb Shape Approach (HSA). The isolation efficiency of the confined cell was determined in terms of the reduction in displacement amplitude, peak particle velocity, and the improvement in elasticity of the foundation bed. From the results, 56% reduction in displacement amplitude was observed in the presence of geocell reinforcement. Similarly, 42% change of resonant frequency was observed as compared to the unreinforced condition. The elasticity of the foundation bed was improved by 102% with the provisions of geocell. Further, it was noticed that the modelling of geocell through the HSA approach provided the accurate prediction of the experimental results. With the help of HSA technique, the effect of confinement area and the height of geocell in reducing the amplitude of vibration was investigated. Further, the parametric study was conducted to investigate the effect of different geocell properties on the dynamic behaviour of reinforced foundation bed. The parametric study results revealed that the geocell modulus and the interface friction angle directly influence the performance of geocell reinforced bed under dynamic loading condition.