Full scale field studies for assessing the vibration isolation performance of single and dual trenches

The ground-borne vibrations induced due to construction operations transmit to the surroundings in the form of stress waves. These vibrations severely impact sensitive structures and cause human annoyance. Present solutions to vibration isolation using barriers are limited to the use of single open and infilled trenches. However, one of the significant drawbacks of using single trenches is its insignificant depth requirements. Hence, an attempt has been made to explore the possibilities of utilizing dual open and infilled trenches by conducting a full-scale experimental investigation under different frequencies of excitations. A well-accepted material, geofoam, was used as an infilling material in the two trenches of the same geometries. The influence of three different vibration locations was analyzed under five combinations of single and dual trenches. The findings from the experimental study suggest that the use of dual trenches suppresses the vibrations more effectively than single trenches. The dual open and geofoam-infilled trenches of the normalized depth of 0.3 decreased the vertical vibrations by 76% and 65%, respectively, compared to no trench conditions. Moreover, to achieve a 50% reduction in vibration, the normalized depths required for the single and dual open trenches were found to be 0.27 and 0.14, respectively.