Load test on a large diameter instrumented bored pile

Agean World Trade Center is being constructed in Izmir. This large scheme comprises of a trade center, a 35-storey hotel tower, a 44-storey office building, a shopping center, a residence hall and a cultural center. Total project area is 20 900 m(2). A detailed soil investigation was conducted at the site. There is a man made recent fill at the ground surface. Underlying this fill layer there are layers of dark gray silty clay and yellowish-brown sandy gravel of Izmir Bay deposits. Cohesive layers have soft to medium stiff consistency whereas cohesionless layers are medium dense, in general. Below Izmir Bay sediments very stiff to hard gravelly clay or very dense clayey gravel layers are encountered. In this paper, a static axial load test on a D=150 cm bored pile has been reported and load displacement data have been analyzed. Test procedure and pile instrumentation are described. Large diameter test pile was constructed at the high office building site. Penetration depth of the test pile is 35m and the tip of the pile penetrates into the very dense clayey gravel. Test pile was instrumented at six different levels by using vibrating wire strain gauges. During the pile loading test load distribution with depth and load-displacement curve at the pile head were obtained. Results of the loading test on the instrumented pile have been interpreted and compared with the ultimate pile capacities derived from CPT and SPT data.