Infrastructure components such as tunnels suffer from deformation, and anomalous deformation behaviour may lead to structural failure and hazards. Deformation monitoring systematically measures and tracks the changes in shape and dimensions so that appropriate actions can be taken to mitigate possible risks.
A research team led by Prof. DING Xiaoli, Director of the Research Institute for Land and Space (RILS), developed a new technology for measuring structural deformation. Typically, a robotic survey system has been used to take sequential measurements at certain points along a long tunnel (Fig. (a)), to determine the displacements of the measured points and hence the deformation pattern of the tunnel. In contrast, the new technology uses a laser instrument and reflectors that direct a laser beam to multiple points (Fig. (b), for example), and accurately detects the displacements of measured points along the travel path of the laser.
This method provides a new alternative to the traditional, costly and time-lapse approach which requires many survey systems moving around in the tunnel and taking section-by-section measurements in order to provide a full set of measurements. The technology is now mature and can be used to monitor deformation of various structures such as tunnels, bridges, buildings and slopes with higher efficiency, lower cost, and in real time.
