Sulphatic claystones exhibit a heavily swelling behavior and are among the most problematic rocks for tunnelling. Their swelling is usually attributed to the transformation of anhydrite to gypsum. The paper questions this simplistic hypothesis through a qualitative ...

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>Shanghai&rsquo;s subway construction has entered a new period of rapid development. A notable characteristic of subway network construction is that the construction environment is increasingly complex. Take Shanghai subway line 10 as an example, in the ...

<p>The 5 m diameter 23.3 km long Yacamb&uacute;-Quibor tunnel is designed to carry water through the Andes from the Yacamb&uacute; dam in the wet tropical Orinoco basin to the semi-arid but fertile Quibor basin in western Venezuela. The tunnel is excavated ...

<p>The tunnel squeezing phenomenonwas first described byTerzaghi (1946)who associated squeezing mainly with clay-rich rocks. Consistent with Terzaghi&rsquo;s original description, the focus of this paper is on tunnels in clays and clay-rich rocks such as clayshales. ...

<p>This paper deals with full face excavation of large size tunnels in rock masses of very poor quality which exhibit squeezing behaviour. Time dependence is accounted for explicitly by using constitutive models which have been validated with reference to ...

<p>The occurrence of occasional sinkholes or very large settlements over EPB driven tunnels has been documented on a number of projects. Primary responsibility for avoiding sinkholes must lie with the tunnelling contractor, and the shield manufacturer. Almost ...

<p>A brief overview of jet grouting in Brazil is followed by &ldquo;why and when&rdquo; basics in relation to ground improvement for safe tunnel excavating. A number of case histories are reported - mostly NATM tunnels involving what were seen as difficult, ...

This paper describes the design methodology adopted for stabilization measures of a twin bored highway tunnel in Northern Greece, where severe cracking and translational displacements of the temporary support shell were observed. Cracks occurred due to an ...

The Gotthard-Base Tunnel will be the worlds longest traffic tunnel, with a length of 57 km. The tunnel is part of the New Alpine Transverse in Switzerland. The dual purpose of this project is to provide a highspeed link for passengers between Germany in the ...