UnconventionalRock SupportDesign Assumptions to Optimise Concrete Mega
The Västlänken project in Gothenburg changes Central station from terminal to transit station, where three additional stations are built. One of them is Haga Station, located in a rock cavern. In the middle of underground station, a row of columns acts as rock support and carry loads nearing 150 MN in compression. This paper presents a sustainable approach to optimization in the design, which was agreed with the owner. To limit the additional expansion stresses due to temperature, two main measures were implemented - study of the rock elasticity and temperature simulations in the station. The aim of the rock elasticity study was to establish a spring stiffness to be used in structural calculation, which allows expansion of the column submitted to temperature loading. By temperature simulations, actual temperature extremes, which will occur during the station lifetime are determined, which avoid the use of normative temperature range. By implementing the rock elasticity in the structural model and decreasing the temperature range, additional stresses due to temperature was reduced up to 60%. The proposed design assumptions were developed including input from different disciplines. Inclusion of MEP and Rock specialists into design has led to sustainable design of concrete structure.