Author(s): Sushil Man Shrestha, Rachana Koirala and Prakash Raj Dhakal

Abstract: Urban heritage zones across seismically active regions face a critical challenge in preserving the structural stability and cultural integrity of unreinforced masonry (URM) buildings. This research investigates the influence of various retrofitting techniques on the seismic resilience of masonry structures through experimental and analytical evaluation. Scaled masonry wall specimens were retrofitted using four distinct methods—fiber-reinforced polymer (FRP) wrapping, near-surface-mounted (NSM) steel reinforcement, grout injection, and textile-reinforced mortar (TRM) overlays—and subjected to quasi-static cyclic loading to simulate seismic effects. Parameters including ultimate load capacity, displacement ductility, energy dissipation, stiffness degradation, and residual drift were measured to assess performance enhancement. Statistical analysis using one-way ANOVA confirmed significant improvements across retrofitted groups compared to unretrofitted controls. The results indicated that FRP and TRM systems yielded the greatest gains in strength, ductility, and post-yield stability, followed by NSM, while grout injection provided moderate yet consistent improvement. The superior performance of FRP and TRM was attributed to their high tensile strength, effective crack control, and minimal invasiveness, which are essential for heritage conservation contexts. The study concludes that composite-based retrofitting techniques, particularly FRP and TRM, offer an optimal balance between seismic efficiency and architectural preservation. Furthermore, a performance-based framework integrating both structural and conservation criteria is proposed to guide the selection of appropriate retrofitting methods in urban heritage environments. The findings contribute to the advancement of sustainable seismic strengthening practices that ensure both safety and authenticity in heritage masonry structures, supporting global efforts toward resilient cultural preservation.

Pages: 26-30 | Views: 21 | Downloads: 12

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