Вплив жорсткості ростверка стовпчастого пальового фундаменту на перерозподіл зусиль між його елементами

Abstract

From previous studies it is known that the bearing capacity of a pile foundation usually exceeds the sum of the bearing capacities of single piles. The main factors influencing the redistribution of forces between the elements of a columnar pile foundation have been established: piles are better included in the work with a larger step and a smaller length; the grillage is also better included in the work with a larger pile step; with an increase in the number of piles, the share of the grillage work in the total bearing capacity of the group decreases; reducing the number of piles in the group while maintaining the dimensions of the grillage leads to a more efficient use of the work of the piles. But most researchers ignore the influence of the thickness of the grillage plate and the size of the cantilever extension of this plate, i.e. its stiffness, on the redistribution of forces between the piles and the piles and grillage. In this work, mathematical modeling of the work of a pile foundation is performed using the Lira software package. A study of the implementation of the work of a pile foundation with a soil base depending on the size of the grillage, length, number, placement of piles in the grillage and soil conditions was conducted. The studies consider a homogeneous sandy and clayey soil of the base. The main attention is paid to varying the thickness of the grillage with different combinations of its other parameters. It is shown that a change in the rigidity of the grillage leads to a slight increase in the load on the bush, the load perceived by the grillage and the average load on the pile of the bush. The main changes with an increase in the rigidity of the grillage occur in the redistribution of forces between the piles. In stiffer grillages, the share of the load perceived by the corner and extreme piles increases. Changes in the stress state in the grillage body with an increase in its thickness are also analyzed.