Specific Features of Calculating Underground Structures Erected with Use of Freezing Method

Abstract

The article regards the problems arising in building the underground structures and, in particular, escalator tunnels under the built-up areas. In case of a thick mass of weak water-saturated soil such tunnels are frequently made with the use of freezing method. The purpose of this article consists in evaluating influence of the established and degrading ice structures on soils deformations and objects contacting with them. It is offered to assess this influence using the finite elements method contemplating a consecutive solution of temperature tasks and the tasks of stress and strain state of soil in time in 3D erection. The article describes briefly the formula part and specific features of calculating temperatures and deformations of soils. By way of example a calculation of defrosting deformations around an inclined tunnel for one of the deep-laid subway stations in Saint-Petersburg has been made. The data of performed calculation are closely approximated to the full-scale measurements.