Longitudinal joints of tubbings with newly designed high?strength reinforcement

Continuous tunneling using a tunnel-boring machine is very popular method when it comes to the construction of large tunnel projects. The use precast reinforced concrete elements, called tubbings, highly economical way secure post excavation. Unfortunately, loss load-bearing capacity has been observed in past joints between tubbings. Reasons for that are among others required reduction cross section longitudinal joint area and, above all, high normal compressive forces arise due soil pressure. This paper describes experimental testing tubbings conducted at TU Wien. increase newly designed and optimized tubbing with high-strength joint-compressive reinforcement, which was developed patented by Institute Structural Engineering Wien, presented. steel characterized its yield strength 670 MPa, as well available bar diameters up 75 mm. new enables production thinner compared conventional designs, can thus achieve material, transport excavation costs.