Application of Hyperstatic Reaction Method for Designing of Tunnel Permanent Lining, Part I: 2D Numerical Modelling
Abstract: The increase of
bored tunnels in the entire world has raised the question how to design the
tunnel structure in an efficient way. This paper proposes a numerical approach
to the Hyperstatic Reaction Method (HRM) for analysing permanent tunnel
linings. The permanent tunnel lining is known as main structure of tunnel
maintenance during the time. The HRM is one of the analysis methods for tunnel
lining in long term. In this paper, two dimensional numerical modelling is
performed by considering hyperstatic reaction concepts. Loading is done after
the calculation of long term loads, and ground reaction is simulated by
springs. Designing is done for Manjil-Rudabar freeway project, Tunnel No. 2.
The numerical analyses were performed for Operational Design Earthquake (ODE)
and Maximum Design Earthquake (MDE) loading conditions. A new simplified
approach is used for considering the effect of earthquake loading on the tunnel
lining. Then, an interaction diagram between axial force and bending moment
used for investigating the capacity of tunnel lining. The thickness of tunnel
lining and armature are calculated for three sections based on induced forces
in tunnel lining. These forces were different in every section according to the
load combinations, rock mechanics properties, lining properties, and
overburden. The numerical results showed
that the forces in tunnel lining for MDE condition is approximately 50% more
than ODE condition in earthquake loading. This numerical processing presented
that the HRM is a proper, fast, and practical method for designing and
analysing the tunnel lining.
Author: Rahim Hassani,
Rouhollah Basirat
Journal Code: jptsipilgg160032