Аннотация
Hereafter are the results of underground testing by the piles with the method of vertical static testing O-cell (Osterberg method) are presented, which had been made on Expo 2017 projects, buildings of Pavilion in Astana, Kazakhstan, in 2013. Experienced bored piles with a length of 31.5 m, diameter 1000 mm. Bi-directional static load tests carried out in accordance with ASTMD1143.The method proposed by George Osterberg, allows to simultaneously determining the estimated soil resistance under the lower end of piles and on its lateral surface. Feature of O-cell test is that the load is applied not on the pile head, and the body of the pile, where is a jack (power cell), which works in two directions. Power cell (O-cell) shares the experimental pile into two parts: upper (upper test item) and the bottom (lower test item). Hydraulic jack is installed at a depth of 2/3 the length of the piles-16.8 m. This O-cell test can obtain biggest bearing capacity of boring piles on difficult soil conditions.