Vertical stiffness of piles and redistribution due to interaction for linear change of soil modulus by depth

Abstract

The paper shows some characteristic problems of determining the axial stiffness of the pile and redistribution in a group. Some advantages and drawbacks of the use of individual design models are indicated. In the redistribution, the zero iteration is considered, which a condition is when the connecting beams or rafts are fully flexible, and the final iteration when the deflections of the piles are equalized. In the zero iteration, all the forces in the piles are of the same intensity, because only the centrically loaded raft is considered, but the deflections of individual piles during interaction are different. Due to the symmetry of the problem, in the zero iteration, only the certain groups have the equalized deflections of piles, but there is no equalized deflection of the groups themselves. In the final iteration, a distribution of forces in which the deflections of the individual piles during interaction are equalized is sought, i.e. a tolerance that is a relative error of 10 -5 in relation to the mean deflection is set. The soil model with the linear distribution with depth is considered. The effect of the distance of piles on the interaction is studied. Key words: Vertical stiffness, Vertical interaction, Redistribution during Pile-Soil- Pile interaction, distance influences of interaction.