• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.2
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• pp.133-148
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• 2011

Construction sites are becoming larger and complex with the growth of national economy. Accordingly, it is important to identify real-time information about materials, equipments, and manpower during construction at sites. Even though research utilizing position tracking sensors has been conducted in architectural engineering fields, this area of research is almost nil in civil engineering fields. Therefore, a feasibility study to find a way to apply position tracking sensors to an in-situ tunnel construction site adopting conventional tunnelling method is performed in this study. A methodology is proposed that the progress management of the tunnelling work can be monitored by checking construction materials needed at job site and the safety management system can be assessed by checking distance between in-situ workers and construction equipments. The most representative materials were identified so that IT technology can be applied by attaching and monitoring sensors to the selected materials. Also, time of arrival (TOA) for a position determination technology along with a wireless network technology was chosen and build wireless network system. The adopted methodology was applied to an in-situ tunnelling site, and verified the usefulness of the proposed system.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.71-82
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• 2006

One of the most popular pre-reinforcement methods of tunnel heading in cohesionless soils would be the fore-polling of grouted pipes, known as RPUM (reinforced protective umbrella method) or UAM (umbrella arch method). This technique allows safe excavation even in poor ground conditions by creating longitudinal arch parallel to the tunnel axis as the tunnel advances. Some previous studies on the reinforcing effects have been performed using numerical methods and/or laboratory-based small scale model tests. The complexity of boundary conditions imposes difficulties in representing the tunnelling procedure in laboratory tests and theoretical approaches. Full-scale study to identify reinforcing effects of the tunnel heading has rarely been carried out so far. In this study, a large scale model testing for a tunnel in granular soils was performed. Reinforcing patterns considered are four cases, Non-Reinforced, Crown-Reinforced, Crown & Face-Reinforced, and Face-Reinforced. The behavior of ground and pipes as reinforcing member were fully measured as the surcharge pressure applied. The influences of reinforcing pattern, pipe length, and face reinforcement were investigated in terms of stress and displacement. It is revealed that only the Face-Reinforced has decreased sufficiently both vertical settlement in tunnel heading and horizontal displacement on the face. Vertical stresses along the tunnel axis were concentrated in tunnel heading from the test results, so the heading should be reinforced before tunnel advancing. Most of maximum axial forces and bending moments for Crown-reinforced were measured at 0.75D from the face. Also it should be recommended that the minimum length of the pipe is more than l.0D for crown reinforcement.