INVESTIGATION OF SHAFT AND BASE RESISTANCE OF A SINGLE BORED PILE USING OSTERBERG CELL

Abstract

Evaluation of pile capacity in soil is an engineering problem of soil-structure interaction. Soil-pile interaction plays an important role in the analysis and design of pile foundations. Geotechnical engineers have recognized this role and many studies have focused on several aspects of the topics related to determination of pile resistance. There are different methods available to predict the ultimate load of a single bored pile, such as theory of bearing capacity of the soil foundation, based on pile load test, semi-empirical methods using in-situ test results, and empirical formulae were suggested by different codes of practice. Still the most reliable method to determine the bearing capacity of a pile is by static load test. This study investigates some of the important problems related to soil-pile interaction. Specific problems examined here include: identify of skin friction and end bearing resistance of pile separately, comparison between the measured results obtained from experimental methods presented by Osterberg cell, (Ocell), or conventional tests and these obtained from equations of Egyptian code for soil mechanics and foundations to evaluate and verify the applicability of different methods. The experimental results were used to study the effect of the different parameters such as pile diameter, D, pile length to pile diameter ratio (L/D), and relative density (Dr) on the pile shaft and pile base resistances of bored piles. Also, in this research, the coefficients of lateral soil pressure (KH) and bearing capacity factor (Nq) have been studied. From this study, It can be found that both pile shaft and pile base resistances have affected by the parameters D, L/D, and Dr.