عنوان مقاله [English]
The piles are foundations that transfer the load from building to the subsoil. And generally used in situations where spread or mat footings are not the best choice. Some examples include situations where the surface soil is weak and compressible, the structural loads are very high the upper soil is subjected to scour, and horizontal load capacity is required Due to poor bearing capacity and settlement of the soil, application of the piles have a long history Correct estimation of bearing capacity of piles is one of important issues that is always under attention of geotechnical researchers, because determination of ultimate bearing capacity of piles is required for their safe designing. The effect of various issues such as inhomogeneous, and variety of the soil, water, the diversity of the various combinations of the soil in nature, possibility of the creep, complicate behavior of stress-strain, complicate interaction of the soil and pile, pile material, and methods of construction make some difficulties in determination of the bearing capacity. Transmission of load from the pile to the soil is by the shaft friction and toe. it is important to know the exact of amount the friction resistance, therefore in this study, the shaft resistance of piles in Sorkhrood sandy soil was investigated through 14 pressure loading tests on small scale concrete piles with different dimensions and the obtained results were compared with the results of some other methods.