Conference Dates
September 3-6, 2017
Recommended Citation
Bruno Mattle, Wolfgang Summerer, Sebastian Höser, and Vladimír Bartoš, "Multi-Layer Shotcrete Design for Tunnel Construction" in "Shotcrete for Underground Support XIII: New Developments in Rock Engineering, Tunneling, Underground Space and Deep Excavation", Dietmar Mähner, Institute for Underground Construction, FH Münster, Germany Matthias Beisler, ILF Consulting Engineers, Asia (Thailand) Frank Heimbecher, Institute for Underground Construction, FH Münster, Germany Eds, ECI Symposium Series, (2017). https://dc.engconfintl.org/shotcrete_xiii/24
Comments
Shotcrete is an essential support element for conventionally driven tunnels. Traditionally shotcrete is applied in multiple layers for construction reasons, but for the design the lining is considered as monolithic. This is acceptable, in case the time lag between the application of each shotcrete layer is short, corresponding to one construction step. A different situation occurs, when an additional shotcrete layer is applied with a large delay. In that case the system consists of a pre-loaded and a stress-free layer and needs to be designed accordingly. Currently there is no explicit design procedure incorporated in the design codes, but only recommendations for design, such as relevant codes to be applied and the requirement to consider the pre-loading conditions of the first shotcrete layer. The paper presents and discusses a standard-conform (Eurocode 2) method for design of a concrete cross section consisting of two layers.
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