Building Risk Assessment For Urban Rail Transit Systems In India - Current Practices And Challenges

The construction industry has one of the largest numbers of injuries compared to other industries. Thus, reducing accidents and determining construction risks are extremely important. One of the essential steps for construction safety management is hazard identification and risk assessment, since the most unmanageable risks are from unidentified hazards. While the urban rail transit systems are being developed rapidly in almost all major cities of India, adjoining Existing Building Structures and historic sites are facing possible threats of unexpected damages and accidents. The protection of these structures becomes one of the major challenges specifically when the infrastructure being developed involves construction of underground tunnels passing through old cities. The assessment of settlement induced damage on buildings during the preliminary phase of tunnel excavation projects, is nowadays receiving greater attention. Analyses at different levels of detail are performed on the surface building in proximity to the tunnel, to evaluate the risk of structural damage and the need of mitigation measures. The current paper presents current practices being adopted in India for prediction and excavation of tunnelling induced ground movement and building damage risk-assessment. The paper highlights empirical and numerical approaches towards predicting settlement induced damages on buildings during the tunnelling, detailed step by step methodologies for conducting building condition surveys, evaluating associated hazards, and adopting adequate building risk identification and mitigation methods. The paper also discusses associated technical and contractual challenges and highlights way forward to overcome them.