COMPUTER AIDED DESIGN OF COLUMN FOUNDATIONS FOR BUILDINGS

Abstract

Foundation is very important part of any structure. Loads from the superstructure are transferred to the soil through the foundation. Foundations can be of many types depending upon the type of loading and the soil condition. For ordinary structures located on reasonable firm soil, it usually suffices to provide a separate footing for every column such a footing is called isolated footing. When the load is distributed from the wall to a wider area, and are continuous throughout the length of the wall, wall footings are provided. Combined rectangular and trapezoidal footings are used when the columns are very near to each other or when the bearing capacity of soil is less or the end column is near to the property line. Raft foundations are commonly used where the soil has low bearing capacity or there is a possibility of differential settlement. However economy of materials solely depends upon the method of design adopted. Normally foundation costs 15-20 % of the cost of superstructure. A computer package on the design of all the above mention foundations based on the provision of Indian standard code has been developed in C++ language using various facilities of TURBO-C++. User can feed data through data file or through keyboard by interaction with screen. Data file can be prepared by running specified program on hard disk or through floppy drive. The results of the program are shown in the form of screen Window output and simultaneously stored in a file. Output of the design part of the program in the form of the net upward soil reaction, bending moment, length and width of the footing, overall depth of the footing etc has been shown in the Window screen. It also calculates the maximum bending moment in the footing member which provides help for design of footing. Relevant codal provisions related to selection of diameter of bar, cover to reinforcement, spacing of reinforcement have been incorporated to provide the information to user at the time of feeding data. The package carries out design checks necessitated by code during various stages of design. Important design parameters are subsequently checked at various stage foe good results. The user of this package should have sufficient knowledge in foundation design and be well familiar to IS code provisions. But to refresh the memory and to help the new user, the relevant knowledge base at appropriate place is flashed on screen