EFFICIENT DESIGN OF OPENINGS IN SCL TUNNELS

摘要

Advanced design tools combined with the improved knowledge of material behaviour provide opportunities for improved designs. Every case however should be examined individually. The proposed design philosophy exploits the capabilities of non-linear 3D FE analysis and the plasticity characteristics of steel fibre reinforced SCL in order to optimise the design of openings in SCL tunnels. This approach has been applied successfully by Dr. Sauer & Partners in numerous projects. The avoidance of additional reinforcement permitted rapid construction progress and delivered considerable health and safety benefits by avoiding the need for manual handling, the need to work at height and steel fixing. Extrapolating the savings discussed in Table 2 in a mined station with 20 openings for example, may result in savings of 120 days in programme duration, 90 tonnes of steel, 3,000m~3 of concrete, 3,000m~3 of excavated material and 1,000 tonnes of CO_2 emissions. This solution supported the industry drive of maximising the use of robotic and remote construction methods, ln-tunnel and surface measurements during and after construction showed excellent correlation with the predicted tunnel deformations, thus validating the design approach and assumptions.