The paper presents the kinematics of rock instability of a high limestone promontory, where the Monemvasia historical site is situated, in Peloponnese in Southern Greece. The instability phenomena poses a significant threat to the town located at the base of ...

Overstressing of the rock surrounding a tunnel can result in either brittle fracture of the intact rock or shear failure along pre-existing discontinuities such as joints or shear zones. These two types of failure can co-exist and the extent to which the failures ...

<p>In this paper the historical development of the Hoek-Brown failure criterion and the associated Geological Strength Index (GSI) has been presented.</p>

Case studies of difficult rock masses for slope excavations at Egnatia Odos Highway.

A discussion on the use of the geological strength index (GSI) for the characterisation of tectonically undisturbed but lithologically varied sedimentary rocks rock masses is presented. Two GSI charts are proposed for estimating the mechanical properties ...

The highly variable nature of deeply weathered Oporto granite posed significant challenges in the driving of the 2.3km long Cline and the 4km long S line of the Oporto Metro project. Two 8.7m diameter Herrenknecht EPB TBMs were used to excavate these tunnels ...

This paper presents a methodology for estimating the properties of heterogenous rock masses such as flysch.

In tunnelling through heterogeneous rock masses, such as the flysch, it is important to attempt to obtain reliable estimates of potential tunnelling problems as early as possible. This enables the tunnel designer to focus on the selection of optimum routes ...

This paper is focused on the applicability of the GSI classification system to these highly heterogeneous rock masses and proposes an extension of the GSI system to account for the foliated or laminated weak rocks in the lower range of its applicability.