Vibration Isolation of Foundation Systems Using Geosynthetics Barriers: Fid-Bau Portal

Vibration Isolation of Foundation Systems Using Geosynthetics Barriers

Hegde, Amarnath / Venkateswarlu, Hasthi

The isolation of foundation systems from the ground vibrations has been one of the prime interests of geotechnical engineers. Over the years, different methods have been adopted to isolate the foundation systems from ground vibrations. The latest trend is to use the barrier systems made from the geosynthetics in such applications. An attempt has been made in this study to quantify the performance of the barriers created using geosynthetics in mitigating the vibrations. For the study purpose, a field vibration test was performed on the three different reinforced barrier systems prepared in a test pit of size 3.6 m × 3.6 m × 1.2 m. It includes unreinforced, geogrid, and geocell reinforced barriers. To generate the ground vibration, dynamic excitation of varying magnitude was applied using the mechanical oscillator supported on a concrete block. The isolation descriptors, namely amplitude attenuation factor, degree of efficiency, and attenuation coefficient, were evaluated to highlight the vibration isolation potential of each barrier system. From the field test results, the inclusion of the geosynthetics was found to enhance the isolation effectiveness of the barrier system significantly. Maximum improvement in isolation parameters was observed in the case of a geocell barrier as compared to other cases. In the geocell barrier condition, more than 52% increase in the degree of efficiency was observed as compared to the unreinforced barrier. Isolation efficacy of the geocell barrier system was further improved by infilling the geocell pockets with the geomaterial having a higher friction angle. Also, the geocell barrier exhibited the maximum value of the attenuation coefficient as compared to other cases.