DISPLACEMENT RELIABILITY ASSESSMENT OF DYNAMIC LOADED PILE USING WINKLER METHOD

During previous earthquakes, a large number of used piles have been damaged, which unfortunately have been recorded in a small sample of usable information. Therefore, it would be very useful to obtain close-to-realistic information on designing and determining the behavior of the piles. The purpose of this paper is the modeling of soil and pile using Winkler's method and its probabilistic analysis under the dynamic load of the earthquake by applying uncertainty of input parameters of soil and concrete. For this purpose, by programming in the MATLAB, dynamic analysis in the time domain is combined with the New Mark method and the Monte Carlo Simulation (MCS) as a tool for probabilistic analysis to determine the probability distribution of the displacement velocity, and acceleration of each point of the pile. In this way, the plie is modeled as beam elements, stiffness and damping of the soil, by linear springs and dampers are modeled respectively, and optional earthquake force is considered on the bedrock. The MCS is a computational algorithm that involves building models of possible results by substituting a range of values for any variable with inherent uncertainty. To verify, the results of the displacement of the pile and the spatial response of the site are compared by the output of PLAXIS and Deepsoil deterministically. Using probabilistic analysis, it is possible to determine the probability of outputs of the model. Also, in this paper, the effect of the pile length on its probabilistic displacement in the dynamic analysis is assessed and the maximum displacement probability density functions of them are compared. The results indicate that with increasing the length of the piles, the average displacement of the pile head increase. Furthermore, with increasing the length of the piles the standard deviation of displacement of the pile head also increases. This means with increasing the length of the piles the uncertainties of pile displacement increase.