Graphical Comparison of Theoretical and Actual Settlement for Axially Loaded Piles

A primary purpose of this paper is to determine an adequate approach to the problem of axial load-settlement relationship. This paper will show that without the aid of a computer a load-settlement curve can be closely approximated. Graphical interpretation of settlement versus load has been very limited with an increased use of the computer. The degree of accuracy depends upon the individual using this method and can be compared to an algebraic or a computer solution of load-settlement. In the past, pile design was always a problem of complex equations along with many unknown variables. A solution at that time was to permit a piling company to provide piles which would meet working load requirements. If a pile failed to meet the design specifications, failure was ascribed to inadequate and unforeseen soil conditions. Fundamentally, piles are used as deep foundations to transfer load through soft upper layers to hard lower layers. Soil borings clear some uncertainty of subsurface conditions; therefore, borings for all construction sites are required for the entire depth of soil to be used. Average values of cohesion and angle of internal friction are not truly representative of either a full section of soil or an entire depth of soil. Extreme precautions are then necessary in order that subsurface conditions be determined. More uncertainty stems from how pile and soil act under loading conditions. Test pile results may partially indicate subsurface soil conditions, but sometimes test piles are not sufficiently exclusive to give a complete picture of a site. Test piles for this research are a necessity for the comparison of actual settlement and theoretical settlement