Assessing potential building damage caused by leakage to urban tunnels

Building damage is a major risk for urban tunnelling. In areas with soft soil conditions, water ingress to bedrock tunnels can cause significant pore pressure reduction, consolidation settlements and damage to nearby buildings and infrastructure. In Norway, guidelines to determine leakage limits are based on a national database, containing data on water ingress, pore pressure reduction and influence zone. To support future projects, the database has been implemented into an ArcGIS tool and merged with the Ground Impact and Building Vulnerability method to assess potential building damage at early project stages. In this paper, the adopted methodology is presented and its application is shown for a new subway tunnel in Oslo, Norway.