Paper Title
Influence of Seismic Incident Angle on Response of Water and Wastewater R.C. Tanks

Water and wastewater, above-ground and elevated reinforced concrete reservoirs appear to have very high importance for our modern civilization. In the past, it has been recognized that the reinforced concrete reservoirs under seismic ground motions have been particularly susceptible, where in some cases, concrete reservoirs had undergone collapse. Modern design procedures of water and wastewater reinforced concrete tanks are based on the principles of Performance-Based-Seismic-Design, which have been proposed for the most types of civil structures. A reliable procedure for the seismic design of these structures seems to be compulsory, taking into account that strong earthquakes leads to intense damage or even to collapse of reinforced concrete tanks. Although the rather large number of research studies that have been recently published for the seismic behavior and capacity of concrete tanks, there are some important gaps to comprehend their inelastic behavior under strong earthquakes. The aim of this article is the examination of the influence of the earthquake components’ incident angle on the behavior of symmetric in plan reinforced concrete tanks subjected to three-dimension earthquake records. The maximum response values for various incident angles are evaluated using inelastic time-history response analysis. It is found that earthquake incident angle is vital to evaluate reliably the maximum-worst inelastic response of water and wastewater concrete reservoirs. Index terms - Water and wastewater concrete tanks, inelastic behavior, earthquake incident angle.