Retrofitting techniques for reinforced concrete structures subjected to blast induced vibrations

The present study investigates the performance of regular and irregular shaped buildings subjected to blast-induced vibrations by performing a non – linear time history analysis. The study employs nonlinear dynamic analysis using ETABS software to evaluate the effectiveness of various retrofitting techniques, including reinforced concrete jacketing, steel jacketing, and fiber reinforced polymer jacketing, in mitigating the adverse effects of underground mining blast loads. The analysis considers a 10-ton blast load at a standoff distances of 60, 70, 80, and 90 m. The RC jacketing involves adding a concrete layer with additional reinforcement to improve structural load bearing capacity and seismic resistance. Steel jacketing enhances structural resilience by enclosing concrete elements with steel plates and angles, increasing strength, ductility, and resistance to dynamic loads. The Fiber Reinforced Polymer (FRP) jacketing is a lightweight, high – strength method that enhances structural performance and durability with minimal disruption, particularly effective in blast mitigation scenarios. It is observed from the study that the C shaped and L shaped buildings are worst affected due to blast induced vibration. To mitigate these adverse effects, jacketing techniques have been introduced to enhance the structural resilience of the buildings, The RC jacketing with 100 mm thickness, steel jacketing with 4 L angles at each corner and FRP jacketing as a coating material demonstrates superior performance in reducing column failures and maintaining acceptable storey drift ratios, as per IS 456:2000, particularly in square and rectangular shaped buildings. The study highlights that all jacketing methods improved structural resilience, with FRP jacketing shows the best overall performance in retrofitting of L and C shaped irregular buildings to ensure the safety and integrity of building subjected to blast induced vibrations.