ABSTRACT
“Rv.555 Sotra Connection PPP Project”, aims to ease the traffic between Øygarden and Bergen, in Western Norway. This paper presents the most recent updates of Kipledalen section case study, with a focus on the employment of the reinforced ribs of shotcrete (RRS) as permanent lining solution under shallow overburden and geotechnical uncertainties. A 2D FEM back-analysis is performed based on displacements acquired during drill & blast operations, from May to August 2024, confirming the effectiveness of the solution with a high safety level. The same model is adopted to calibrate a rigid support based on spaced steel profiles enveloped by shotcrete. A comparison of induced displacements and static equivalence validates the correlation between the RRS design and this model. The current work aims to provide a fruitful and simple example to asses the convenience of RRS, as a stiff-lining option, in terms of worksite operations and simplicity in the implementation.
