Influence of subtitle base stabilization with geogrids on the deformability of the earth bed during thawing

¹ Emperor Alexander I St. Petersburg State Transport University, Department Construction of roads of the transport complex, 9 Moskovsky Ave., 190031 Saint Petersburg, Russia
² Emperor Alexander I St. Petersburg State Transport University, Department Surveying and design of railroads, 9 Moskovsky Ave., 190031 Saint Petersburg, Russia

^* Corresponding author: oldmasterplus@mail.ru

Abstract

In this research papers, several fundamental questions connected with the assessment of the influence of subgrade stabilization using the geogrid reinforcing method on deformability of subgrade during thawing are considered, as also the basic provisions of methods of calculation of the stress-strain state of subgrade reinforced by geogrids during thawing. Several practically significant tasks, such as reduction of general deformability, reduction of uneven distribution of deformations, increase of bearing capacity, and ensuring the stability of earth bed during thawing, can be solved by using modern geomaterials in the construction of earth bed. In order to determine the degree of change in the deformation characteristics of the ground reinforced with planar geomaterials under varying factors of structural, operational, and technological nature, a series of laboratory stamping tests were performed. The test outcomes showed an increase in the total deformation modulus of reinforced soil, depending on the realized variant of reinforcement, under the condition of full inclusion of geomaterial in the work under load, and being the most essential for recompacted soils. The paper proposes a method of accounting for the influence of reinforcing layers of geomaterial on the deformability and bearing capacity of the earth bed during thawing using a conventionally homogeneous equivalent layer with parameters determined by the outcomes of die tests. The proposed method of calculating the stress-strain state of an earth bed reinforced with geogrids during thawing is based on the use of the finite element method and is an effective tool for solving practical tasks of railway construction, including permafrost conditions.