Determination of the stress-strain state of a group of piles by numerical simulation of their interaction with the base according to field research data

Abstract

Engineers often face the question: - Which software package should be chosen to solve a particular problem? The following software systems are used to solve geotechnical problems: 1) Plaxis; 2) Midas GTS NX; 3) Abaqus; 4) Lira - SAPR. Each of the software packages has certain advantages and disadvantages.
 In this study, the software package "Lira - SAPR" and "Midas GTS NX" are used. With the help of which numerical modeling of the interaction of a group of piles with the base was performed, which is described in the experience of Bartolomey A. A. [1].
 The stress-strain state was compared, which was obtained using the following variants of the models of the "base - pile foundation" system:
 1) software package "Lira-SAPR":
 1.1) piles are modeled by single-node finite elements, which are located with a step specified along the length of the pile and have rigidity in different directions and approximately take into account the surrounding soil around the pile and under its tip (FE-57);
 1.2) the soil environment is modeled by non-linearly deformable volumetric finite elements; piles - rod finite elements.
 2) "Midas GTS NX":
 2.1) the soil environment is modeled by non-linearly deformable volumetric finite elements; piles - rod finite elements that have a "virtual" connection with the surrounding soil;
 2.2) soil environment - similarly; piles - volumetric finite elements with the parameters of reinforced concrete.
 It is shown that the choice of the software package and the method of modeling the base affects the stress-strain state of the "base - pile foundation" system.
 Modeling the base using the belt stiffness coefficient leads to a quantitative difference between the obtained results and the field study. This modeling method is the least labor-intensive and fast. The disadvantage of this modeling method is that it is necessary to create a separate model for each stage of the load.
 Modeling the base with volumetric finite elements with a nonlinear deformation law will disturb the identification of the design parameters of the base, which is quite laborious. The disadvantage of this modeling method is that it is necessary to control the correctness of the dimensions of the finite elements and their joint work.

Serviceability analysis of the grain storage facilities foundations

“…Використання методу скінченних елементів (МСЕ) для моделювання НДС системи фундаментів дозволило, зокрема, враховувати: взаємний вплив їх окремих елементів; стадійність прикладання навантаження та його повторюваність; нелінійний характер деформації основи, тощо [7][8][9][10], -а також уточнити характеристики основи за результатами геодезичних вимірювань у часі [11][12][13].…”