Analytical analysis of the stress-strain state of the system “mechanized equipment complex - support – rock mass” in the bottomhole area of the shaft

Abstract

The development of new deposits requires the construction of deep and super deep vertical shafts. The duration of their construction reaches 8 - 10 years with multi-billion capital investments. To reduce the payback period of these costs, it is necessary to develop and implement effective solutions to increase the speed of sinking operations through the wide introduction of brand-new mechanized equipment complexes. In response to the sinking in the bottomhole area of the shaft, the following geotechnical system is being formed: “tunnelling system - support - rock mass”, the regularities of which require further study. For these purposes, an analytical method for calculating the shaft support can be used in the context of consideration of a planar contact problem at various phases of the system operation. The mutual coordination of individual phases in accordance with the classical concepts of the underground structures mechanics is possible using a correction factor to the magnitude of horizontal stresses in the rock mass. In this paper, we developed the algorithm which determines this coefficient, taking into account the influence of the main technological factors: the pressure of the jack system of the complex and the speed of sinking.