Analysis of shaft lining stress state in anhydrite-rock salt transition zone

Maxim A Karasev,Anatoly G Protosenya,Vladislav V Petrushin,Andrey M Katerov

doi:10.17794/rgn.2022.1.13

Abstract

The main question of this paper is the stress-strain state prediction of the vertical shaft’s combined lining located at the interface of two layers of dolomite and salt. The study predicts geomechanical processes at the contact of the dolomite layer and the salt layer in the vicinity of the vertical shaft’s expanded section, taking into account the operating life of a vertical shaft is equal to 50 years. The results combined lining’s stress-strain state, represented as a four – layer medium, where the external layer is concrete, and the three inner layers are used to account for the heterogeneity of cast-iron tubing and are compared with the results received when taking into account the pipe structure. The solution of the problem was carried out in a three-dimensional statement. The calculation of the tubing lining, considering its actual geometry, will increase the accuracy of the forecast of the stress state of the lining, which in turn will favourably affect the justification of its parameters.

Highlights

The construction of vertical shafts in salt mines at great depths is associated with intensive geomechanical processes, which introduce uncertainty in the choice of lining type and justification of its parameters, and have a significant impact on the long-term stability of the shafts and the technical condition of the lining
We propose a methodology for predicting the stress state of the vertical shaft lining, located at the contact of two rock layers - dolomite and rock salt
2017) shows that the use of concrete and reinforced concrete lining cannot ensure the long-term stability of a vertical shaft at great depths in salt formations. This means that either lightweight lining structures are used to line the shaft, or a cast-iron tubing lining structure with sufficient load-carrying capacity to bear external loads is used as a lining

Summary

Introduction

The construction of vertical shafts in salt mines at great depths is associated with intensive geomechanical processes, which introduce uncertainty in the choice of lining type and justification of its parameters, and have a significant impact on the long-term stability of the shafts and the technical condition of the lining. We propose a methodology for predicting the stress state of the vertical shaft lining, located at the contact of two rock layers - dolomite and rock salt The innovation of this methodology is in the consideration of cross-sections, taking into account the detailed geometric configuration of the cast iron tubing lining in order to increase the reliability of the prediction of stress development within the structure. The results of the stress state of the vertical shaft lining are compared in the spatial idealization of the shaft lining and in its consideration as a multilayered medium These studies were carried out as part of the design and calculation of shaft lining in the Nivenskoe deposit. The proposed study can be used for further implementation of the methodology for calculating parameters of shaft lining of the Nivenskoe deposit

General information about the object of study

N umerical model of “lining-rock” interaction system

Design of cast-iron lining

Results

Conclusions