Abstracts Category : Other

STRENGTHENING MASONRY FOR SEISMIC ACTIONS IN DEVELOPINGCOUNTRIES

by Ather Ali

The study presented aims to provide the most viableseismic retrofit solution for rural masonry. Muzffarabad is onesuch region where excess of unreinforced masonry structures claimedthousands of lives during 2005 earthquake. Field study wasconducted in the region to familiarize with the dynamics of localconstruction industry before suggesting a suitable retrofitsolution. Polypropylene (PP-) band retrofit has been selected asthe most viable solution for retrofitting existing masonrystructures in terms of cost, material availability and ease ofapplication. To prove the efficiency of PP-band retrofit, numericalsimulations and laboratory tests were conducted to assess theseismic efficiency of PP-band retrofit. Material tests wereconducted in accordance with BS-EN to familiarize with themechanical properties of locally available materials in Kashmirregion and to provide material data for numerical analysis. Testsrevealed lower strength and elasticity for bricks in comparison tomaterials found in developed countries, due to the unregulated andnon-standardized manufacturing of masonry units and high watercontent in mortars. Shake table tests were conducted to test theeffectiveness of PP-band retrofit masonry under dynamic vibrations.Results show that PP-band retrofit can enhance the post peakperformance by at least 7 times in comparison to non-retrofitspecimen. Real-scale structure retrofit with PP-band survivedaccelerations of up to 2g without any life-threatening damage,thus, proving to be an economic and efficient strengtheningsolution for rural communities. Following the shortcomings observedin Room-1, connection detail for PP-bands in Room-2 was revised toachieve a 100% performance enhancement. Numerical models weredeveloped to predict cracks in masonry and analyse diagonalcompression test models, in accordance with ASTM standards. Theresults showed 30% higher residual strength after cracking for PP-band retrofit masonry and the wall integrity was maintained forhigher deformations.Advisors/Committee Members: SWAILES, TOM T, Swailes, Tom, Mandal, Parthasarathi.