Crack width design approach for fibre reinforced concrete tunnel segments for TBM thrust loads

摘要: Abstract Concentrated loads induced during the excavation stage by Tunnel Boring Machines (TBMs) is still a matter of discussion into tunnelling construction field, this having strong impact from both technical (e.g., durability and service conditions) economic perspectives. Fiber reinforced concrete (FRC) has been gaining acceptance as structural material for producing precast segments proven to lead various advantages respect traditional concrete, especially improving crack control transient loading situations. In sense, several experimental programs numerical studies were previously carried out in which different geometric mechanical governing variables analyzed and, results, valuable conclusions derived. Nonetheless, there are observed lacks gaps related with optimum reinforcement design (FRC strength class and/or amount steel bar reinforcement) often hindering use fibers main segments. The purpose research consist developing parametric analysis TBM-thrust effects on FRC means using non-linear 3D FEM, calibrated full-scale tests. results used determine range classes suitable controlling TBM thrust phase. expected be useful tunnels designers when establishing requirements.