Basic provisions for the design of the roadbed for high-speed railway lines

Abstract

The article reflects the relevance of the organization of high-speed train traffic on the railways of Russia, describes the procedure for obtaining the initial data and presents technical solutions to the roadbed differentially depending on the composition, properties and condition of the soils, as well as the types of roadbeds (embankments, cuttings, zero places) and climatic conditions. The width of the roadbed on top (the main platform) is set equal to b = 15.5 m, the width between the tracks - b_м = 5.5 m. The surface of the main site should be given a two-sided slope of 0.04 from the middle of the intertrack space towards the edge of the roadbed. The embankments up to 9 m inclusive and cuttings up to 9 m or less should be designed for group solutions. Instead of embankments with a height of more than 9 m and embankments within marshes with a depth of more than 7 m, overpasses should be provided, and in place of cuttings with a depth of more than 9 m - tunnels. Embankments in the marshes up to 7 m deep, as well as on moist and wet grounds, are projected from draining soils with the substitution of soils in the base for these soils. A protective layer is provided in the upper part of the roadbed of all types of clayey soils, as well as in zero places and in cuttings composed of fine and dusty sands, easily eroded and friable rocky grounds. Draining soils are used in the protective layer. When sand is used in the upper part of the protective layer (on the main site) and on its slopes, with the exception of the lower part, a height of 0.8 m is assigned to reinforce these sands with liquid and powdered polifilizers. The steepness of the slopes is assumed to be 1:2. Clay soils under the protective layer in the cuttings, at zero places and embankments are also subject to strengthening. It is proposed to use reinforcing layers from geogrids based on basalt fiber in combination with waterproofing geomembranes and drainage material providing effective water drainage, increasing bearing capacity and stability in complex engineering and geological conditions, including karst, characteristic for polygons of high-speed lines.