Development of a real-time and automated TBM guidance system at a pipejacking site

Tunnel Boring Machines (TBM) have seen wide applications in pipe jacking and microtunnelling projects. Accurate TBM positioning and attitude measurement are crucial to guiding the TBM advance, controlling line and level of the subsurface tunnel, and tracking TBM production progress. In this paper, we firstly evaluate pros and cons of available TBM guidance systems. Our evaluation covers prevalent passive and active laser targeting systems for short and straight drive, along with gyroscope-based inertial navigation systems specifically designed for curve drive. We then propose a real-time, automated solution to TBM guidance by application of state-of-the-art robotic total stations. Our solution can provide the precision and cost-effectiveness as required in practice. Moreover, based on accurate TBM position data collected, TBM attitude is determined by a methodology of vector observation, without the use of traditional inclinometers. Simulation study of the proposed solution indicates that the 3D positioning accuracy by a common, midrange robotic total station is better than 5 mm with surveying distance up to 500 m, which outperforms the majority of existing TBM guidance systems.