Modifications of Conventional Rigid and Flexible Methods for Mat Foundation Design

This study provided the findings of the theoretical and experimental investigations into the modifications of conventional rigid method for mat foundation design carried out at Islamic University of Gaza. The main objective of the investigation was to satisfy equilibrium equations to construct shear force and bending moment diagrams using the conventional rigid method by finding factors for adjusting column load and applied soil pressure under mat and producing a computer program using C#.net based on the modified proposed way of mat analysis suggested by the researcher to carefully analyze the mat by drawing the correct closed moment and shear diagrams to each strip of mat and to determine reliable coefficients of subgrade reactions for use of flexible method jointly with performing plate load test on sandy soil on site and analyzing and studying a large number of tests of plate load test on sand soil performed by material and soil laboratory of Islamic University of Gaza and to generate a simplified new relation to account for K mat as function of known settlement and compare it to the relation given by Bowels (1997). It will also discuss the differences of the obtained results from design analysis using the proposed solution of conventional rigid method and the flexible method using finite element. In addition, it will launch an interesting finding shows a significant reduction of the amount of flexural steel reinforcement associated with the conventional rigid method that will be decreased by reducing its bending moment obtained by up to 15% after applying a load factor to match the numerical obtained values of bending moment from flexible method by applying a finite element available commercials software. Discussions emanating from the above investigation will provide interesting findings and will balance equations to construct shear force and bending moment diagrams using the new proposed solution analysis for conventional rigid method passing through factors to adjust the column load and the soil pressure together and it will also present experimental reliable coefficient of subgrade reactions taken for real soil to be employed when using flexible method analysis using available finite element computer software