Abstact:
This paper presents the results of a seismic monitoring data acquired during the excavation of a shallow NATM tunnel, performed using the plasma blasting technology. This tunnel was excavated under a thin coverage of soil, located in a dense urban area, under one of the most important avenues of the municipality of São Bernardo do Campo, Brazil. This scenario demanded a non-conventional rock fragmentation technology that could reduce the blasting induced vibration, noise and eventual public complaints. Thus, it was used the plasma blasting method for breaking the hard rock. Measurements of the velocities and vibration frequencies of particles during the fragmentations in the tunnel face were performed using six engineering seismographs installed in the lining areas of the tunnel and on important buildings on the ground surface. Results were confronted with three Technical Standards. In conclusion, the plasma blasting technology was presented feasible, from the technical and safety point of view, since the limits established in project and in Technical Standards were integrally obeyed, as well environmental and structural impacts were avoided. In addition, the present paper intends to contribute to a better understanding of the plasma blasting impact on the surrounding structures and on the lining areas along the existing tunnel, besides to disseminate the in-situ test data registered by engineering seismographs.
Reference:
SANTOS, Felipe Schaeffer; HELENO, Aline Fernandes; RIBOTTA, Luiz Carlos; ORLANDO, Patricia Del Gaudio; IYOMASA, Wilson Shoji. Seismic monitoring during the excavation of a shallow NATM tunnel using the plasma blasting method. In: TA-AITES WORLD TUNNELS CONGRESS – WTC, 2020, Kuala Lumpur, Malaysia. Proceedings… [on line] 6 p.
Document with restricted access. Log in to BiblioInfo, Biblioteca-DAIT/IPT to access the PDF document:
https://escriba.ipt.br/pdf_restrito/176910.pdf
This paper presents the results of a seismic monitoring data acquired during the excavation of a shallow NATM tunnel, performed using the plasma blasting technology. This tunnel was excavated under a thin coverage of soil, located in a dense urban area, under one of the most important avenues of the municipality of São Bernardo do Campo, Brazil. This scenario demanded a non-conventional rock fragmentation technology that could reduce the blasting induced vibration, noise and eventual public complaints. Thus, it was used the plasma blasting method for breaking the hard rock. Measurements of the velocities and vibration frequencies of particles during the fragmentations in the tunnel face were performed using six engineering seismographs installed in the lining areas of the tunnel and on important buildings on the ground surface. Results were confronted with three Technical Standards. In conclusion, the plasma blasting technology was presented feasible, from the technical and safety point of view, since the limits established in project and in Technical Standards were integrally obeyed, as well environmental and structural impacts were avoided. In addition, the present paper intends to contribute to a better understanding of the plasma blasting impact on the surrounding structures and on the lining areas along the existing tunnel, besides to disseminate the in-situ test data registered by engineering seismographs.
Reference:
SANTOS, Felipe Schaeffer; HELENO, Aline Fernandes; RIBOTTA, Luiz Carlos; ORLANDO, Patricia Del Gaudio; IYOMASA, Wilson Shoji. Seismic monitoring during the excavation of a shallow NATM tunnel using the plasma blasting method. In: TA-AITES WORLD TUNNELS CONGRESS – WTC, 2020, Kuala Lumpur, Malaysia. Proceedings… [on line] 6 p.
Document with restricted access. Log in to BiblioInfo, Biblioteca-DAIT/IPT to access the PDF document:
https://escriba.ipt.br/pdf_restrito/176910.pdf
