_
This paper presents in-situ load tests to define the bearing capacity of piles constructed in graphite schists during the construction of the A2 Highway (Kicevo-Ohrid) in Western Macedonia. Several tests have been carried out on pile foundations of viaducts. The standard test method for static loading of piles with diameter of Ø1200 mm and length of 16 m will be described here. The estimated axial capacity of piles was 9.0 MN which was calculated analytically. A unique steel platform-reaction system was designed to provide a counterload and was used for the first time in our country. The results show that the deformations of the pile under the effect of the designed load are smaller than those allowed and foreseen in the project. To determine the ultimate bearing capacity of the pile, a numerical modeling was done by calibrating the model for the tested loads and estimating the ultimate bearing capacity of the pile.
