Reliability Assessment of a Single Pile in Unsaturated Substrate under Climate Factors Influence

In the present study the numerical model of the pile embedded in the unsaturated substrate was proposed and tested. The solutions complemented the state of knowledge of the single pile loaded by bending moment in its head, horizontal forces and the environmental influences. The investigated reliability problem was defined by the union of failure events defined such: the excessive horizontal displacement of the pile head, the rotation beyond the limit state and maximum tensile stress in a pile material. The analytical model of water flow in the unsaturated soil was used. The profile of suction allowed to estimate the complete description of layers above the groundwater table. Flac 3D was used for modelling presented task. The main part of problem is reliability analysis of a single pile in complex environment. Due to the lack of analytical solutions the computations were done by the method of response surface in conjunction with based on polynomials regression. The Ditlevsen's bounds were taken into account for the calculation of system's reliability.