this paper addresses the problem of quantifying the mechanical contribution of rockbolts installed systematically around tunnels (regularly spaced around the tunnel) excavated in rock masses. assuming that the mechanical contribution of grouted rockbolts is that of increasing internal pressure within a broken rock mass, a new procedure for computation of ground response curves for a circular tu...

This paper addresses the problem of quantifying the mechanical contribution of rockbolts installed systematically around tunnels (regularly spaced around the tunnel) excavated in rock masses. Assuming that the mechanical contribution of grouted rockbolts is that of increasing internal pressure within a broken rock mass, a new procedure for computation of ground response curves for a circular tu...

The lining structure of Tunnel Boring Machine (TBM) excavated tunnels is composed of series of precast Reinforced Concrete (RC) pieces which are called segment. At the present paper, a novel method is introduced for seismic retrofitting of segmental tunnels located at active fault zones in rock environment with case study of Amirkabir dam to Tehran water transfer tunnel (Karadj tunnel). The mai...

energy-based optimized design of polymer fiber-reinforced tunnel lining mohammad safi                   analysis of underwater tunnels considering strain-softening behavior in plastic zone ahmad fahimifar; hamed ghadami; masoud ahmadvand; arvin abdolmaleki                                 the effect of operational parameters on penetration rate of a tbm using artificial neural networks- a case s...

This study intends to establish the mechanical properties of polyamide fiber reinforced shotcrete (PAFRS) in terms of compressive and flexural strengths, in accordance with ASTM C1609/C1609M-12. The mechanical properties identified the influence of polyamide fiber content on the PAFRS strength. This study evaluated the toughness of PAFRS and proposed additional toughness level criteria to bette...

According to construction scheme of some weak surrounding rock large span double and multi-arch tunnel works, finite element value simulation method is adopted to research weak surrounding rock deformation characteristic, anchor bolt mechanics characteristic, preliminary support and secondary lining structure mechanical characteristics, etc, and the research result shows that: repeatedly distur...

SPEAR 3 is an upgrade of the 18-cell SPEAR 2 storage ring to 3GeV beam energy, 18nm-radian emittance and up to 500mA circulating current. The existing arrangement of photon beam lines remains largely unchanged, but opportunities arise for additional ID and dipole radiation exit ports. For optimum beam stability, the entire tunnel floor will be excavated and replaced with reinforced concrete. Th...

the joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms of the rigidity of the joints or their rotational stiffness. therefore, the bending moment act...

The joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. Generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms of the rigidity of the joints or their rotational stiffness. Therefore, the bending moment act...

Strengthening of existing circular reinforced concrete columns by CFRP confinement