Prediction of spatial stress–strain behavior of physically nonlinear soil mass in tunnel face area

The article proposes a numerical modeling procedure to predict the stress–strain behavior of rock mass ahead of a tunnel face and its stability as a factor of bearing pressure of temporal support and the model used. The procedure was analyzed in terms of a buried circular-shape opening driven in soil. The geotechnical characteristics of soil mass are accepted from the comparison of the deformation curves obtained in the real-time lab-scale tests and in virtual modeling (virtual calibration). The input parameters were selected to describe the soil mass behavior in the models of elastoplastic body and elastoplastic body with hardening. The influence of change in the temporal support stiffness, assigned as a uniformly distributed load applied perpendicularly to the face surface, on the geomechanical processes in the adjacent rock mass is studied. The model took into account the technology of bench tunneling. The process of formation and qualitative change of the limiting state zone and the hardening zone ahead of the faces is analyzed. The distribution of concentration factors of the maximum principal stresses and the highest shearing stresses around the tunnel is considered. These maximum values in the Mohr–Coulomb model allowed finding the size of the limiting state zone. The analytical procedure of exposure stability criterion calculation by shearing stresses is compared with the modeling results. The values of axial displacements of face in the Mohr–Coulomb model and in the Hardening Soil Model are collated. In the Mohr–Coulomb model, the deformation modulus was set equal to the secant deformation modulus in the Hardening Soils Model. Based on the accomplished research, the recommendations are made for the temporal support design.

Keywords: Plaxis, nonlinear deformation, soil mass, Hardening Soil Modeling, face stability, tunnel.
For citation:

Protosenya A. G., Iovlev G. А. Prediction of spatial stress–strain behavior of physically nonlinear soil mass in tunnel face area. MIAB. Mining Inf. Anal. Bull. 2020;(5):128-139. [In Russ]. DOI: 10.25018/0236-1493-2020-5-0-128-139.

Acknowledgements:
Issue number: 5
Year: 2020
Page number: 128-139
ISBN: 0236-1493
UDK: 0236-1493
DOI: 10.25018/0236-1493-2020-5-0-128-139
Article receipt date: 04.02.2020
Date of review receipt: 18.03.2020
Date of the editorial board′s decision on the article′s publishing: 20.04.2020
About authors:

A.G. Protosenya1, Dr. Sci. (Eng.), Professor, Head of Chair, e-mail: kaf-sgp@mail,
G.А. Iovlev1, Graduate Student, e-mail: gregoriiovlev@gmail.com,
1 Saint-Petersburg Mining University, 199106, Saint-Petersburg, Russia.

For contacts:

G.А. Iovlev, e-mail: gregoriiovlev@gmail.com.

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