NUMERICAL MODELING OF A SOIL PLUG FORMATION DURING AN OPEN END PIPE SUBMERGENCE INTO A ROCK MASS
The employment of a trenchless method of subsurface utility engineering is a viable alternative to the use of open methods. A method of vibro-impact submergence of steel pipes with an open front end into the ground is widely used in the construction of closed underground galleries. Regular cleaning of the clogged pipe from the emerging core is one of the most important operations in this technology. The parameters of the soil plug (density, linear dimensions) depend on the physical and mechanical properties of the soil in which the work is done. The aim of the article is to establish the parameters for the simulation of a soil plug formation when the pipe with an open end is immersed into the rock mass. Also, it is important to determine factors affecting the properties of the soil plug. The work studies the construction of soil mass numerical models during the immersion of pipes under various technological operations. The calculated model of the interaction of the pipe's open end with a soil mass under static loading is constructed for the solution by the finite element method in the ANSYS software package. The adopted approach to the modeling of the soil plug formation when the pipe with an open end is submerged into the mass makes it possible to take into account the elastic-plastic properties of the soil. It provides the opportunity to solve the contact problem for the "pipe surface-soil mass" system and provides interactive optimization of calculation parameters and adaptive reconstruction of the finite elements network during soil consolidation. The main limitations and assumptions in the simulation of the process under consideration associated with the amount of computing resources expended are revealed. The obtained results can be used to construct a dynamic model of the system interaction, as well as to develop a design model for the process of combined pipe cleaning from the core.