An experimental investigation of the effect of barrier trench on vibration propagation on a laboratory scale model.

Vibration waves caused by construction or mining operations may cause damage to nearby structures or sensitive machinery and equipment. Some measures are implemented to eliminate or reduce this negative environmental effect of vibration. The barrier trench, one of these methods, aims to reduce the vibration by creating a suitable barrier between the structure and the vibration source on the ground. In this study, the effect of trench depth and distance from the source on vibration waves was simulated with a designed laboratory-scale test set-up to determine the effective parameters in barrier trench use. In addition, the effects of the superimposition of the source vibration wave with the reflected and refracted vibration waves from the trench, which has not been previously discussed in the literature, were also investigated. A laboratory scale gypsum-plaster block with dimensions of 200 cm × 90 cm x 70 cm was prepared and a Schmidt hammer was used as the impact energy source to generate vibration throughout the gypsum block. A trench barrier was opened at different depths on the test block and 588 vibration recordings were taken by the vibration monitor in different locations of the designed set-up. Statistical analyses were performed using vibration measurement results, trench source distance, and trench depths. As a result, vibration estimation equations depending on trench depth and the distance between the vibration source point and the trench were developed and how the presence of trench affects vibration propagation is revealed. It was found that vibrations increase due to the superposition of the source and reflected waves in front of the barrier trench. As the barrier depth increases, it is understood that the vibrations emanating from the near-surface vibration energy source are better blocked by the barrier. Thus, this study provides fundamental information on designing barrier trenches to avoid adverse effects of vibrations.