Electronic Thesis and Dissertation Repository


Master of Engineering Science


Civil and Environmental Engineering


Dr. Ashraf EL Damatty


Reinforced concrete conical tanks are used in municipalities and industrial applications as liquid containing vessels. Such tanks can be ground supported tanks or elevated on a supporting shaft. Although most design codes provide guidelines for rectangular and cylindrical tanks, no guidance is provided in such codes for conical tanks. Therefore, this thesis is motivated to study the behaviour and design of this type of tanks. In the current study, the accuracy of a design approach based on the provisions of Portland Cement Association (PCA-CCTWP) code for cylindrical tanks combined with an equivalent cylindrical approach provided by the American Water Works Association AWWA-D100 (2005) is assessed. This assessment is done by comparing the internal forces resulting from this method with those obtained from a linear finite element analysis model built in-house. It is noticed that in some of the studied tanks, the PCA-CCTWP approach combined with the equivalent cylinder method is found to be unsafe. As such, and due to the complexity of analysing these conical tanks, a simplified design approach in the form of design charts is provided in this study. This set of charts can be easily used for the analysis and design of reinforced concrete conical tanks subjected to hydrostatic pressure and having a constant wall thickness. This approach is developed using the results obtained from finite element analysis of a wide range of reinforced concrete conical tanks having different configurations combined with code requirements. This simplified approach is then utilized to investigate the economics of reinforced concrete conical tanks versus steel counterparts. A cost analysis is conducted for several conical tanks having different capacities and different construction materials by including both construction and life-cycle costs. In addition to the cost analysis, a general study of the effect of tank dimensions on its cost is illustrated.