Numerical analysis of changing the force factors in temporary lining at the tunnel construction by the NATM

B. Liu,V. Heyets,A. Bulat,Volodymyr Kuprii,Y. Kryzhanivskyi,O. Voloshyn,Sofiia Kuprik,Yevhenii Kripak,Volodymyr Petrenko

doi:10.1051/e3sconf/201910900044

Abstract

The paper presents the results of a numerical analysis of force factors in temporary lining at the tunnel construction by New Austrian Tunneling Method (NATM). The relevance of the performed research is substantiated by the complexity of the temporary lining operation in the form of arches combination, anchors, and shotcrete that arose during construction of the Beskydskyi tunnel in Ukraine. NATM, used in construction, is associated with a change in the sectional area of the working and a staged installation of temporary lining, which leads to a gradual change in the stress-strain state of the “temporary lining – surrounding massif” system. In turn, this leads to a change in the force factors (bending moments and normal forces) in temporary lining. In this study, a series of finite-element models simulating the stages of rock excavation and installation of lining elements have been developed and analyzed. The obtained results allowed to determine the cardinal change of force factors in temporary lining, depending on the stage of construction. Changing the force factors at different stages of the tunnel construction by the NATM makes it possible to perform an optimal selection for temporary lining location.

Highlights

In modern methods of constructing the transport tunnels, for example, in New Austrian Tunneling Method (NATM) one, temporary lining is widely used [1,2,3]
The level of analytical calculation methods does not allow to perform its optimal selection, since the lining operation depends on the change of the stress-strain state in "temporary lining – surrounding massif" system [4, 5]
The purpose of the paper is to carry out a numerical analysis of the force factors of temporary lining in the transport tunnel being constructed by NATM, and an important factor is taking into account the change of the stress-strain state of the "temporary lining – surrounding massif" system when rock excavation in parts

Summary

Introduction

In modern methods of constructing the transport tunnels, for example, in NATM one, temporary lining is widely used [1,2,3]. Temporary lining of workings in the tunnels construction by NATM is often combined and consists of arches, anchors, and shotcrete (in various combinations). It must meet the technical, technological and economic requirements, the list of which is quite wide, and their classification by categories is, in a sense, conditionality. It is simultaneously impossible to meet all the requirements for lining, due to their mutual contradictions (for example, bearing capacity and cost, strength of the element and its mass, etc.)

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Conclusion