COMPUTER AIDED DESIGN OF UNDERGROUND CIRCULAR TANK

Abstract

The advent of inexpensive micro-processor based computer is changing the way structures are designed. More and more problems are being tackled using CAD as it results in cost optimisation and time saving. The design of liquid retaining structures involves tedious calculations and neumerous design charts. Any careless human error may result in fatal error. So, a computer aided design would appear to be necessary. The problem of computer aided design of underground circular tank has been dealt with in this dissertation. Underground tanks are used in water purification, sewage treatment etc. The sides of tank have to resist earth pressure from outside and water pressure from inside. A software "TANK" is developed for design of various elements of tank. Tank is designed under varying site conditions. Both base condition, hinged at base and fixed at base are taken. Tank with large dia. has further option to be designed as cantilever retaining wall. Static and dynamic pressures both can be dealt, with choice resting on user. The position of water table has also been taken into consideration and design is carried out accordingly. Software offers great deal of flexibility in structural design and complies with relevant codal provisions, i.e., IS:456-1978, IS:1893-1984, IS:3370-Pt.1, Pt. II and Pt. IV. It is user interactive software which simplifies input data and guide the user about units. Program is written in Fortran 77. Number of Test examples have been solved using this software to justify its use in practical conditions.