Behavior of Piles under Different Installation Effects by Physical Modeling

Abstract

Many factors influence the axial bearing capacity and performance of deep foundations embedded in sand deposits. Among these factors, the installation method is of great importance. The objective of this study was to investigate the construction effects on pile performance via physical modeling. The frustum confining vessel of Amirkabir University of Technology (FCV-AUT) was employed for this purpose. Six different installation methods were studied: jacking, drilling and grouting, driving, screwing, drilling and placing, and postgrouting. Up to 30 axial compressive and tensile load tests were carried out on different piles on Babolsar sand, from the northern coast of Iran, with relative densities of 45% to 50% within the FCV-AUT. Experimental results show that among different pile installation methods, jacked and precast-in-place piles had the greatest and lowest capacities, respectively. Moreover, the performance results of the different pile types in the FCV-AUT indicate that the axial bearing capacity of piles can be boosted by modification of the installation method. These modifications result in a reduction of the number and size of piles, and consequently result in savings in construction costs and time requirements.