An alternate arrangement of geofoam blocks and air pocket to mitigate confined blast induced vibration

Abstract

ABSTRACT The present study focuses on the performance of intermittent geofoam in-filled (IF) trench as a passive vibration screening when a reinforced concrete (RC) lining tunnel is subjected to internal blast load. The blast analysis of lined tunnel is performed using a three dimensional non-linear finite element (FE) method. The coupled Eulerian-Lagrangian (CEL) analysis tool has been employed in the FE software ABAQUS/Explicit for the purpose of this study. The explosive trinitrotoluene (TNT) has been modelled using Eulerian elements as the blast source in the tunnel. The IF has been installed at the far field from the source to protect the vibration sensitive buildings and equipment in that region. The parameter, which controls the design of intermittent geofoam trench, is its geometric parameters (width, depth, location). EPS geofoam density and soil Poisson’s ratio have been considered to investigate the performance. In addition to IF, another newly proposed technique named staggered intermittent geofoam (SIF) has also been investigated in the present study. The results of simulation show that both IF and SIF can be a very good passive vibration screening technique subjected to blast sources.