Monitoring of TBM-induced ground vibrations

摘要

Hager GeoScience, Inc. (HGI) has been monitoring tunnel boring machine (TBM) vibrations associated with mining of the MetroWest Water Supply Tunnel, a 17.6-mile long, deep-rock, pressurized tunnel outside Boston, Massachusetts. The purpose of the monitoring is to detect TBM-induced vibrations and characterize their waveforms, to study the potential impacts on residences above and adjacent to the tunnel alignment. The monitoring is being conducted at the ground surface as the TBM passes underneath the sensors at depths between 200 and 450 feet. Monitoring is performed using commercially available seismographs and amplifiers. Data are analyzed using signal analysis software developed by HGI. TBM mining has been occurring simultaneously along three tunnel headings with variable geologic settings. HGI has monitored at locations along each heading.