BEHAVIOUR OF ISOLATED BORED ENLARGED BASE PILE UNDER SUSTAINED VERTICAL LOADS

Abstract

Many static methods and dynamic formulae are available in the published literature, for predicting the pile capacities. So also, the procedures for evaluating the ultimate capacities based on the load test data. All these methods and procedures, instead of providing unique answer, give different load values. Thus placing the designer in a dilemma with respect to the method that is to be adopted.Most of experimental suggestions are based on the results of small size piles driven in sandy deposits. But none of these suggestions try to dwell upon their limitations.In the present study an attempt has been made to analyse the behaviour of isolated piles, based on series of field tests, conducted on bored piles with enlarged base in a uniform deposit of silty sand.The performance mechanism of isolated piles have been studied. Also suggestions for estimating their capacities based on load tests and static methods have been provided. The predicted load-settlement behaviour by the elastic theory approach does not agree with the observed one.