A COMPUTER PACKAGE ON ESTIMATION OF SOIL PARAMETERS AND DESIGN OF FOUNDATIONS

Abstract

With the advent of personal computers, most of the design organizations are fully equipped to make a change over from manual based design to computer aided design practice. Using such facilities, the geotechnical engineer is now in a position to interactively design the footings with the use of suitable software. The present work is an effort to develop a user friendly comprehensive software package for design of footings covering estimation of soil parameters, proportioning and structural design of footings. The most popular and commonly adopted correlations for estimation of soil parameters from field tests such as static cone penetration test and standard penetration test have been compiled. These correlations are available in the form of charts which are translated into appropriate equations and incorporated in the package. Foundations are proportioned by a procedure of trials accounting for a number of parameters like soil type, its stiffness and compressibility properties, position of water table, shape and size of footing etc. A computer program available for proportioning of footings has been checked, modified and, incorporated in the package. The footings are designed structurally to cater the forces induced and in accordance with the guidelines as specified by relevant IS codes. The package developed is capable of designing individual footings of square, rectangular, circular and wall footings using both limit state (LSM) and working stress methods (WSM) of design. The footings may be sloped or pad type. The package is used to solve a few numerical problems and the results are presented to illustrate some of the features of the package. Assuming some typical example data results are obtained on soil design parameters, proportioning and structural design of footings. Comparative studies are made on certain parameters based on the results and it has been found that (i) Soil profile obtained from SCPT correlations may be reliable (ii) the limit state method of design produces economic design when compared to working stress method and (iii) the pad footings are less economical than sloped footings. ii