Detecting Seismic Waves Induced by Blast Operations at a Limestone Quarry by Means of Different Transducer Mounting

Abstract

The use of explosives to fragment the rock is very widespread in quarrying activities. This technology produces significant environmental impacts due to ground vibrations generated by blasting operations. In order to characterize this phenomenon, accurate measurements of seismic waves are required and one of the most critical aspects in field tests is represented by the coupling method between the transducers and the soil. This phenomenon may generate the distortion of the recorded waveform thus affecting the affordability of the sample itself. Moreover, the decoupling assumes a growing importance in those sites where the rock is not outcropping and the transducer is buried. For this purpose, different methods are tested in an opencast limestone quarry in the centre of Italy. Firstly, ground vibrations in terms of peak particle velocity (PPV) were recorded according with the method suggested in UNI 9,916 and consisting in burying the detectors into the soil at a suitable depth. Secondly, the same parameters were recorded by means of transducers fixed to the ground with some sand bags thus maintaining the proper adherence. Finally, the data obtained through these two different methods are compared and discussed.