Towards a safety management approach for adjacent buildings in tunneling environments: Case study in China

This paper develops a systematic approach with detailed step-by-step procedures for safety management of existing buildings adjacent to tunneling excavation. The potential safety risk of a specific nearby building is assessed within four different risk levels, with the spatial neighbor relation (hazard parameter) and the building health condition (vulnerability component) taken into account. Compared with the traditional two-stage approach, a reasonable balance between the system safety and cost constrains is reached in the developed systematic approach, where the safety risk assessment is added in the first stage, and the assessed safety risk level acts as a decisive role in the depth of the subsequent two-stage numerical analyses. It is suggested that numerical simulation analyses should be employed in the situation where the existing building lies in a risk level of III (Medium risk) or IV (High risk). A case concerning the protection of a five-story framed building adjacent to a twin-tunnel in China is utilized to verify the applicability of the proposed approach. The impact of both the tunnel excavation on the soil displacement and building foundation deformation is further analyzed in details. Results demonstrate the feasibility of the proposed approach, as well as its application potential. The proposed approach can be used by practitioners in the industry to provide guidelines on guaranteeing the system safety of adjacent buildings in tunneling environments. At the same time, the analysis cost can be greatly reduced, especially when a large number of existing buildings adjacent to tunneling excavation need to be protected.