Design soil resistance for deep foundation

抄録

The following article represents various methods for soil resistance – R identification under single pile based on the Republic of Kazakhstan guidelines. Analytical values obtained from formulas and empirical values based on plate load and CPT tests for deep foundation design bearing capacity. To study and evaluate design soil resistance – R just beneath the footing, theoretical calculations executed, at the same time, set of plate load test probing carried out on the depth 7.0 – 11.0 m, and diameter of the cross section plate 30 cm. Furthermore, dynamic and static test took place for single pile bearing capacity identification. Consequently, code of practice values validated with obtained experimental values. The pile cross section is 30 x 30 cm and length is 8.0-10.0 m. The physical and mechanical soil properties on the depth of 8.0 – 12.0 m state that bearing layer underneath the pile toe is loam with following design characteristics: cohesion = 27 - 41 kPa, angle of friction = 23 - 26 degrees, density = 19.2 – 19.5 ton/m3. It has to take into account that soil is saturated and the site located in impounded area. Load – settlement figure states that factored bearing capacity is 403 – 784 kN. Dry resistance unit soil results of CPTs for loam is 241 and 582 kN, with bearing capacity equals to 658 kH. Dynamic tests results reveal bearing capacity of the pile 606 kN. Plate load test results perform settlement of 0.58 cm in the range of 0.1 – 0.5 MPa loading. The modulus of deformation is 12.0 MPa. Settlement – loading figure and plate load test curve is linear at 10.2 m depth. Comparative results of single pile bearing capacity perform difference between design values of soil resistance underneath the pile toe in terms of shaft surface in analytical and experimental approaches.