INVESTIGATION OF THE INTERACTION OF TUNNEL STRUCTURES WITH GROUND MASSES UNDER THE INFLUENCE OF DYNAMIC LOADS

Аннотация

In this paper, the task is to calculate the VAT of the underground part of tunnel structures, taking into account the viscosity of the soil. The object of the study is tunnel structures located in an underground massif under the influence of a distributed load from the upperpart ofthebuilding, thegarage's ownweight and theweight ofthe soil. Keywords:Underground structure, pipeline, support structure, foundation, resource. 1. Introduction. Underground structures of the system are one of the main components of oil and gas and petrochemical production, therefore their safety largely depends on the technical condition of pipelines. Underground structures of the system of pumping and compressor units are in the most unfavorable operating conditions, since they experience significant vibration effects, both from the machines and from the transported medium. These effects have a complex nature and are caused by pressure pulsation, flow disruption, changes in the direction and speed ofits movement, acoustic resonances, interaction of flows at the points of pipeline branching and other factors. In some cases, the vibration effect is transmitted to the supports of the structure through the soil [1,2,3,4]. Any structure is built on a soil foundation and has some parts located in the soil. Therefore, the strength, stability and normal operation of a structure are determined not only by its design features, but also by the properties of the soil and the conditions of interaction between the structure and the foundation. The cost of a foundation averages 12% of the cost of a structure, labor costs for its construction often reach 15% or more of the total costs, and the duration of work reaches 20% of the construction period. In difficult soil conditions, these indicators increase significantly. Therefore, the improvement of design and technological solutions in the field of foundation construction leads to significant savings in material and labor resources, and a reductionin theconstruction timeofbuildings and structures [5,6,7]. 2. Application of the finite element method. The problem is solved numerically, using the finite element method. The basic idea of ​ ​ the finite element method is that continuous quantities (displacements, stresses, pressures, etc.) are approximated bya discrete model on a finitenumber of subdomains. For this purpose, a computational domain is allocated, which is discretized into a finite number of elements. These elements have common nodal points and together approximate the original computational domain. The continuous quantity is approximated on each element through the nodal values ​ ​ using interpolation polynomials. Interpolation polynomials are used to approximate continuous functions in mathematical equations describing the physical process being studied. Then the discrete model constructed in this way must satisfy the boundary (boundary and initial) conditions of the problem. These conditions are satisfied using various approaches known in FEM. Discretization of the computational domain S into elements is the first step towards solving the problem. This step is very important, since poor or imperfect https://ijmri.de/index.php/jmsi volume 4,issue3,2025 532 discretization can lead to erroneous results. When choosing discretization, the main attention is paid to the following rules: - finer discretization should be carried out in areas where large gradients of quantities are expected, and in places where the boundary of the computational domain changes; - to achieve rational numbering of elements and nodes of the discretized domain, it is necessary to use sequential numbering of nodes when moving in the direction of the smallest body size. After the discretization of the computational domain is carried out, the calculation parameters are selected and entered into the program, it is possible to obtain a solution to the selected class of problems. It is necessary to test the solution to the problem on a model problem for this class of problems. After the problem is tested, it is possible to proceed to complicating the computational domain, boundary conditions, etc. The smaller the differences in the model problem and the specific technical problem, the greater the reliability of the obtained solution. Therefore, the need for rigorous analytical solutions will always be relevant. Any calculation should be duplicated by a calculation with a finer discretization of the computational domain. Depending on the difference in the results of such comparative calculations with a continuous value, one can judge the ratio of the obtained results of the calculation scheme used. For a numerical solution to the problem, it is necessary to introduce O0, which is a finite part of thehalf-space P,i.e. it is necessary toposeand solveproblems fora finiteregion W = W + W + W . (1) 1 2 0 Let us consider linear oscillations of an elastic half-space containing a rectangular obstacle under the influence of a harm