THE EFFECT OF IMPROVEMENT SURROUNDING SOIL ON BORED PILE FRICTION CAPACITY

There is very close relation between the pile capacity and surrounding soil conditions. In cohesionless soil the bored pile effected on surround soil byloosen , deposits through a combination of pile volume replacement and exist of pile case used for installation of bored pile. .the pile foundation usually designed to exceed the weak soil to the firm deposit .in this study improvement of the weak soil surround the pile and observing the effect of improvement on pile capacity for bored pile. The improvement soil surround pile model was design to be as one block and kept this block will effect noticeably on pile load capacity results. the improvement suggested in this study is compacting and replacement for surrounding soil . for this purpose testing program prepared by selection two types of sand soil one as the origin soil and the other as improving soil (soil will be compacted and replace surround pile model) . pile model prepared for this purpose is consist of reinforcement steel bar covered with cement mortar ,50 kN automatic electromechanical compression machine was used for testing load- settlement test on pile model. testing procedure includes changing the diameter of compacted soil around pile model and execute the load settlement test and compare the results with each other and with results obtained from Hansen equation.