Capacity of Frozen Soil for Shallow Tunnel Pre-Support underneath a Building Founded on Wooden Piles

This thesis analyzes completion of a binocular tunnel underneath a historic building at low cover using ground freezing for tunnel pre-support and building underpinning. The low depth required tunneling through a big number of timber piles set in groups that serve as foundations for the steel frame, brick and masonry building. Tunneling was carried out using a sequenced excavation with concrete for tunnel support, commonly referred to as the New Austrian Tunneling Method (NATM). During the tunneling the building remained operational for its mainly commercial purpose. The analysis focuses on the performance of the building foundations, frozen soil and tunnel opening. Observations from the construction-monitoring program are utilized in the development of a numerical model to study the performance of the support system consisting of timber piles, frozen soil and tunnel lining.

Authors : Gall,  Vojtech

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