ABSTRACT
The development of new railway infrastructure requires rail lines to be routed through city centres for the best accessibility. Such routing usually requires that it passes in a tunnel, under existing buildings. Tunnel investments in dense urban areas always generate risks for existing buildings. Regardless of the scale of the investment, no risk associated with tunneling should be ignored. Two large-diameter railway tunnels are planned under a densely built-up city centre with unique and historic buildings. For both tunnels, the low ground overburden, the varied geological structure, sensitive infrastructure and numerous over a hundred-year-old wells located along the tunnel route required special attention during investment preparation. This paper presents the process of analysing risk and im-pact of settlements on existing buildings and describes the designed methods of enhancing the ground under buildings for the design of one of the tunnels. The risk analysis included hundreds of buildings. The focus was given to presenting the existing risk factors taken in-to account and the preparatory process for identifying these factors. In addition, the paper attempts to validate the risk analysis carried out based on the settlement values acquired from the monitoring system in a second tunnel currently under construction.
