Design of The Reinforced Concrete Cylindrical Tank with a Spherical Cover in Ethiopia
The aim of this research is to design a tank for storing water in two different methods and then decide the better method. The stored water has used for many purposes, such as drinking water for people and animals, irrigation for agriculture, fire suppression and many other daily activities. The cylindrical tank with a spherical cover has designed to rest on the ground. It has a complex shell geometry. For design simplification, dividing into different parts are required. These parts are spherical, cylindrical and ring beam. The height of the cylindrical part is 20meters and spherical cover is 5meters. The overall size of tank is 25meters high and have 20meters in diameter. Between the cylindrical tank and the spherical cover, there is a ring beam. The purpose of the ring beam is to connect the spherical and the cylindrical parts thereby allowing for vertical displacement. The tank foundation has a depth of 1.2meters to support the overall tank shell. The main target of the research is to select the better way to design the tank, which will have a high carrying capacity, and sustainable strength; by using reinforced concrete to resist maximum internal stresses. The design focuses on its intended use, the available materials, location and climatic condition. This is important in order to ensure life safety and long-term performance of its essential functions. The scope of this research is the comparison between two theories, which are the membrane state theory; in which the bending moments are absent in the cross-sections and the momentless state theory; which is valid only where the structure has the possibility of free displacement in all directions.
Keywords - Water Tank, Spherical Tank Cover, Cylindrical Tank Shell, Reinforced Concrete.