Iso-velocity maps. A vibration control tool in quarries

Abstract

Urban growth around mining areas has brought problems such as neighborhood's discomfort due to blasting vibrations, which can cause structural damage to the houses, dust and atmospheric overpressure. In Brazil, environmental restrictions are increasingly rigorous and seismic monitoring is required as an environmental control measure. This study aims to analyze a methodology for application of iso-velocity maps in quarries located in urban areas and evaluate options for building iso-velocity maps. This work was performed in a quarry located in the State of São Paulo and four blastings were monitored. All blastings had similar features and they were evaluated in the same bench. For each equation, directional, scaled-distance parameters were estimated and different iso-velocity maps were made and compared. It is concluded that geophone disposition must adjust to the monitoring purposes. Eight to fifteen aligned geophones are adequate for a scaled-distance curve. Sixty-four or more geophones, spatially and homogeneously distributed, can generate an iso-velocity map concerning a single blasting. High variability of rock mass features seems to prevent obtaining good results when the seismographs are not homogeneously distributed surrounding the blasting.

Comparing blast-induced ground vibration models using ANN and empirical geomechanical relationships

“…Several scaled-distance attenuation equations were estimated for different directions. Published field blast data (Ramirez Canedo 2013 andRamirez Canedo et al, 2015) were used in this study. Figure 1 shows a satellite view of the mine and the distribution of the sensors in Ramirez Canedo's study.…”

“…For the particular directions elected by Ramirez Canedo (Ramirez Canedo, 2013 andRamirez Canedo et al, 2015) to obtain the attenuation, the resulting equations might be preferable over other solutions (ANN, GSI, etc. ), despite the relatively few number of sensors used in the interpolation.…”