Determination of the actual excess excavation ratio (section “Kosino” - “Yugo-Vostochnaya”)

Abstract

Conducting tunneling construction at any depth causes deformations of the earth's surface and, as a result, additional movements of the surrounding buildings, as well as changes in the stress-strain state of the ground mass. When modeling the site of work to assess the impact of the construction of tunnels, it is necessary to take into account the volume loss of soil. The purpose of this work is to determine the technological parameter with further averaging and application in the design of dispersed soils. The article considers the impact on buildings from the construction of a two-track tunnel from the «Kosino» station to the «Yugo-Vostochnaya» station in Plaxis in a two-dimensional and three-dimensional with a design volume loss of soil of 1.5 %. The construction of the tunnels was carried out by a shield with earth pressure balance with a cutting diameter of 10.8 m. The maximum depth of the tunnel from the ground surface is about 27.0 m, the construction site is dominated by dispersed soils. For the considered section of the construction of the distillation tunnel, the calculated volume loss of soil for the two-dimensional problem varies in the range from 0.32 to 0.41 %, for the spatial problem - from 0.52 to 0.78 %. With the same additional draft of the building, there is a percentage increase from 62 to 90 % between the calculated parameters obtained in the schemes in both settings. Taking into account the calculated volume loss of soil at the design stage, obtained from the results of this article, in similar engineering and geological conditions, contributes to the rational distribution of funds, reducing the volume of geotechnical monitoring and measures for the preservation of buildings in compliance with the required standards and safety regulations.