• Ravi P. Kasampara

Abstract: Double-decker elevated water tanks are vital infrastructure components, particularly in urban areas with limited land availability, as they maximize water storage capacity by utilizing two stacked reservoirs. These structures are especially critical in earthquake-prone regions like Gujarat, India, where their seismic resilience is essential to meet heightened post-earthquake water demands. This study explores the Response Reduction factor (R) of double-decker reinforced concrete (RC) elevated water tanks through static non-linear analysis using SAP2000 software. The research investigates double-decker elevated water tanks as vertically stacked set of Intze type and Circular water tanks with various capacities of 250 m³+100 m³ and 500 m³+150 m³, varying staging heights (12 m, 16 m, 20 m), seismic zones (II to V), and bracing types (normal and cross) to assess their impact on the R-factor. Structural parameters such as Base shear, Time period, Over-strength factor (Rₛ), Ductility reduction factor (Rµ), and Redundancy factor (RR) are analyzed across various tank configurations under full and empty water conditions. 28 models are prepared based on the selected geometries and material properties, followed by pushover analysis to simulate non-linear structural behavior under seismic loading. The two-mass model by Housner, separating impulsive and convective water masses, is employed for seismic analysis. The study concludes that R factor is significantly affected by staging height, seismic zone, and bracing configuration. Higher staging heights (e.g., 20 m) and more severe seismic zones (e.g., Zone V) yield lower R values due to decreased over-strength and ductility, reflecting increased seismic demands. Cross bracing enhances the R factor compared to normal bracing by improving redundancy and stiffness, with R values decreasing from Zone II to Zone V. Empty tanks exhibit higher R values than full tanks due to altered dynamic responses. The study highlights the need for better seismic design rules for double-decker water tanks to ensure they remain safe and functional during earthquakes.

Response Reduction Factor, Double-Decker Elevated Water Tanks, Pushover Analysis

"STUDY ON RESPONSE REDUCTION FACTOR OF RC ELEVATED WATER TANKS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 5, page no.f493-f502, May-2025, Available :http://www.jetir.org/papers/JETIR2505656.pdf

"STUDY ON RESPONSE REDUCTION FACTOR OF RC ELEVATED WATER TANKS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 5, page no. ppf493-f502, May-2025, Available at : http://www.jetir.org/papers/JETIR2505656.pdf