Today, the use of ground concrete tanks for storage various type of fluids has become increasingly developed.

Since these tanks are susceptible to environmental damage such as corrosion and contamination, the design of these tanks must be continuous and uninterrupted operation during and after an earthquake. They also prevent water contamination during possible accidents. Factors affecting the design of tanks include efficiency, durability, safety, cost, and passive defense factors. The first step in designing a tank with a specific volume is to determine the dimensions, which in Publication 123 recommends a length-to-width ratio of 3 to 2 for rectangular concrete tanks with a fixed and specific volume, in the absence of other technical limitations. With the recommended ratio and fixed volume, there are many choices for height. Now the main question is which height for fixed volume should be considered in the design so that the lowest base shear coefficient is obtained in addition to observing the factors affecting the design. The answer to this question is the main topic of this article. For this purpose, a base height function called the Hs function is proposed. The proposed function is a criterion for the range of suitable geometric dimensional ratios. It limits the number of height ratio choices. Therefore, by performing fewer calculations, the base shear coefficient can be evaluated and its optimal value applied in the design.