Civil engineering experts at the Hong Kong Polytechnic University have developed a new trenchless system that is expected to further promote the application of Trenchless Technology in the region.
Led by Associate Professor Dr Lu Ming of the Hong Kong Polytechnic University (PolyU) Department of Civil and Structural Engineering, the research team has developed the TunnelingGSV, which stands for Guide, Sense and Visualise. When coupled with a microtunnel boring machine (TBM), the TunnelingGSV can continuously and automatically survey the TBM’s positions by a robotic total station and derives any tunnel alignment deviations in real time, said the researchers.
Further, given the co-ordinates of three observation points on the TBM, TunnelingGSV can accurately determine the rotation angles of the TBM in the underground space by invoking sophisticated computing algorithms.
The TunenelingGSV was developed in collaboration with industry and utility companies and will provide a more convenient microtunnelling and pipe jacking installation methods for engineers, based on the integration of automated data collection with real time computing.
The first prototype of TunnelingGSV system was set up at a microtunnelling site near So Kwun Wat, Tuen Mun in Hong Kong for a three month field trial in late 2009. Coupled with a micro TBM, the TunnelingGSV system successfully installed a 55 metre long section of a 220 metre, 1.5 metre diameter concrete tunnel
It is expected that the TunnelingGSV will be able to provide tunnelling engineers with information of potential hazards, such as the possible derailment of a TBM or excessive progression speeds, which may lead to the over-cutting of underground soil and undesired ground settlement in the adjacent area. It also automatically produces accurate as-built records in terms of the tunnel alignment and the tunnelling operations.
According to Dr Ming, Trenchless Technology is developed in response to communities’ growing concern for environmental sustainability of underground piping works. Compared with traditional open-cut methods, the use of microtunnelling and pipe jacking for the installation of underground infrastructure provide a sustainable and community and environmentally friendly installation method for densly populated cities, such as Hong Kong.