Queen’s University Background
When underground openings (tunnels, cavities, etc.) are created, the redistribution of stresses around the openings usually results in ground or rock movement. The gradual movement of rock over time is called convergence. Convergence should be monitored in order to predict and/or avoid failures before they become unsafe. Current technologies for convergence monitoring requires the installation of infrastructure including reflective prisms or borehole extensometers, which not only limits the monitoring range to a select few locations, but can also be labour intensive and costly.
Researchers at Queen’s University have invented a novel infrastructureless, mobile laser-scanner-based system for convergence monitoring. The system can detect and may be configured to warn about the possibility of tunnel convergence. The system may move through a tunnel, either autonomously or manually, to acquire 3D point clouds of all or a portion of a tunnel at selected times. The data is used by the system to compute a set of indicators that describe the local environment. Indicators are subsequently amalgamated to estimate the probability that convergence has occurred in a given region.
The system is cost-effective as it does not require the installation of infrastructure and is not labour intensive to operate.
The system enables convergence to be monitored throughout the entire length of a tunnel or indeed full mine-wide coverage instead of a few points.
The system is rapid and accurate for convergence monitoring which can increase safety at the site.
Queen’s University is seeking companies interested in licensing, further developing and/or commercializing this technology.