Akshay Satishkumar Baheti

Life-Cycle Risk Assessment of RC Structures under Earthquake and Fire

Fragility and risk assessments of reinforced concrete (RC) structures against various design loads and their combinations is required to be conducted for evaluating structural vulnerability. This is typically done at the design stage. However, during the service (design) life of a civil engineering structure, it is important to investigate the change (increase) in the risk posed to a RC structure on account of multiple hazards such as, the two uncorrelated (non-cascading) independent hazards: earthquake and fire. That is to say, that the risk to the structure as a result of fire may increase if the structure has already been damaged by, e.g. an earthquake; and vice versa. With an aim to evaluate reduction in the desirable design factor of safety due to deterioration of the RC elements (with and without strengthening) over the service-life of a building by using a suitable well-established degradation model, this research proposal plans to investigate the life-cycle risk assessment of RC structures exposed to earthquake and then fire. A series of high repeatability tests will be conducted, by applying cyclic loading (to simulate earthquake damage) to scaled-down RC elements in the Structures Laboratory at the University of Queensland (UQ) and then testing them under heating using the H-TRIS apparatus (to simulate the subsequent fire exposure) in UQ's fire laboratory. Numerical models of the RC elements will be developed at the Multi-Hazard Protective Structures (MHPS) Laboratory at IIT Delhi and validated using these test results. The validated numerical models will then be used for conducting multi-hazard vulnerability assessment of the RC elements under earthquake and fire. Subsequently, risk posed to the structures during its service-life, with degradation of the RC elements due to life-cycle deterioration, earthquake and fire, will be evaluated.