Innovative Monitoring for Urban Tunneling

摘要

Tunneling in soft ground for the Regional Connector Transit Corridor project in downtown Los Angeles had many challenges including typical risks of damage to buildings and utilities, community disruption, and environmental impact. A considered approach to monitoring structures and ground movement was required that had to draw on new innovations in the instrumentation industry. As well as structural monitoring, the planning and effects of compensation grouting had to be measured and quantified. Unique measures were taken to start tunneling under existing buildings immediately upon launching the earth pressure balance (EPB) tunnel boring machine (TBM) with very low ground cover. This paper provides an overview of the measures taken to safeguard all assets with particular attention to innovation in wireless instrumentation to control compensation grouting and understand structural response and visualization techniques of in-ground data that has revolutionized the way that volume loss can be viewed real time.