Blast-Induced Ground Motion in Geo-media

Abstract

AbstractThe increase in the activities of accidental as well as terrorist-initiated blast explosion cause cataclysmic effects on occupants and structures. The underground, as well as above-ground explosion, results in several hazards; one such hazard is a blast-induced ground motion (BIGM). It is important to predict the intensity of vibration due to the BIGM to safeguard the personnel and structures. In an event of a blast, the ground vibrations are measured based on parameters such as peak particle velocity (PPV), peak ground acceleration (PGA), and principle frequency content (PF). These parameters quantify the ground motion characteristic depending on intensity, arrival time, and wave duration; whereas, the ground vibration is usually expressed in terms of the PPV. In the case of underground blast, the prediction of the BIGM due to large-scale explosion depends upon the charge weight, radial distance, depth of burst (DoB), site constants, and type of propagating medium. The prediction of the PPV includes various empirical relations, code-based equations, predictor equation using regression analysis based on experimental data, artificial neural network (ANN) models, and finite element (FE) based numerical simulation methods. The differences in the estimated PPV values may occur due to discontinuities and the presence of water table in the geo-medium. Herein, the PPV due to an underground explosion is estimated using the abovementioned approaches. Also, the FE-based numerical simulations are carried out to investigate the influence of different geo-media like granite, limestone, sandstone, and sandy loam for prediction of the BIGM parameters such as PPV, PGA, and PF. The simulation-based estimate of the PPV for different geo-media is compared with the abovementioned approaches for various scenarios. The numerical simulations confirmed the ground shock attenuation with an increase in the radial distance as the PPV shows reduction in the amplitude with an exponential decay. The charge shape and DoB also show significant influence on the PPV estimation. The PGA and PF estimates based on the empirical and code-based equations show good resemblance with those predicted using the numerical simulations. The comparison of various prediction models has been presented, helping researchers and designers to select the adequate PPV predictor equation or approach based on scenarios and site conditions.KeywordsBlast-induced ground motionUnderground explosionPeak particle velocityPeak ground acceleration