METHOD AND APPARATUS FOR ESTIMATING OPTIMAL COLUMN-PILE STIFFNESS RATIO OF BENT PILE STRUCTURE WITH VARYING CROSS-SECTION IN CONSIDERATION WITH COLUMN-PILE INTERACTION

摘要

A method for calculating an optimal column-pile stiffness ratio of a bent pile with a varying cross section according to the present invention comprises the steps of: (a) numerically analyzing the upper structure of a pile according to a boundary condition assuming fixation of the lower structure of the pile to the ground surface with respect to the bent pile with the lower structure and the upper structure of the pile to calculate subgrade reaction against the ground surface; (b) numerically analyzing the lower structure of the pile according to the boundary condition applying the subgrade reaction, calculated via the numerical analysis of the upper structure of the pile, as a vertical load applied to the bent pile to calculate a spring stiffness matrix for the ground surface; numerically analyzing the upper structure of the pile by setting the calculated spring stiffness matrix as the boundary condition of the upper structure of the pile for the ground surface; (d) repetitively performing the step of (b) and the step of (c) and extracting a structural analysis model when each or all of a member force and a displacement of the upper structure and the lower structure of the pile at the boundary of the ground surface converges equal to or less than a set level as a final structural analysis model; (e) extracting a relationship between the column-pile stiffness ratio and a horizontal crack load ratio according to data on the horizontal crack load calculated according to given column-pile stiffness ratio values based on the final structural analysis model; and (f) calculating the column-pile stiffness ratio, corresponding to an inflection point on a relationship graph between the column-pile stiffness ratio and the horizontal crack load ratio, as an optimal column-pile stiffness ratio.