Publication

Review of the TBM performance in blocky rocks with potential face stability issues

Jian Zhao, Andrea Delisio
2013
Article de conférence
Résumé

In blocky/jointed rock masses, the combined effects of the rock mass structure and the in-situ state of stress may lead to severe instabilities of the excavation face which may become "blocky". Large breakout and rock block detachment from the tunnel face may occur with consequent paramount effects on the normal TBM operations. These effects generally comprise the abnormal wear of the cutters and cutterhead, due to the heavy dynamic impacts against the hard rock blocks at the face, as well as frequent damages to the muck transportation facilities due to the presence of blocks in the muck. Therefore, an increase of the maintenance requirements and TBM downtimes is generally registered when the face presents an irregular/blocky structure. This work focuses on the review of the TBM performance at the Lotschberg Base Tunnel, where substantial occurrence of face instability phenomena was observed. More in detail, the main effects that blocky rock conditions may have on the TBM performance, in terms of machine penetration rate, utilization time and total advance rate, are underlined. Finally, a new prediction model suitable for blocky rock conditions with potential face stability issues is presented.

À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
Concepts associés (29)
Tunnel
vignette|Construction du tunnel sous la Tamise en 1830. Un tunnel est une galerie souterraine livrant passage à une voie de communication (chemin de fer, canal, route, chemin pour piétons). Sont apparentés aux tunnels par leur mode de construction les grands ouvrages hydrauliques souterrains, tels que les aqueducs, collecteurs et émissaires destinés soit à l'amenée, soit à l'évacuation des eaux des grands centres et certaines conduites établies en liaison avec les barrages et usines hydro-électriques.
Basalte
thumb|Lave en coussins de basalte vu au fond de l'océan, au niveau de Hawaï. Le basalte est une roche magmatique volcanique issue d'un magma refroidi rapidement et caractérisée par sa composition minéralogique : plagioclases (50 %), de pyroxènes (25 à 40 %), d'olivine (10 à 25 %), et de 2 à 3 % de magnétite. Sur Terre, il a une origine volcanique et est un des constituants principaux de la croûte océanique. Sur la Lune, il constitue la surface des mers lunaires. Ce serait un constituant important des croûtes de Mars, Vénus et Mercure.
Convective instability
In meteorology, convective instability or stability of an air mass refers to its ability to resist vertical motion. A stable atmosphere makes vertical movement difficult, and small vertical disturbances dampen out and disappear. In an unstable atmosphere, vertical air movements (such as in orographic lifting, where an air mass is displaced upwards as it is blown by wind up the rising slope of a mountain range) tend to become larger, resulting in turbulent airflow and convective activity.
Afficher plus
Publications associées (30)

Supercell Thunderstorms in the Alpine Region - From Weather Radar Observations to Idealized Modeling

Monika Feldmann

The high-impact nature and increasing occurrence of severe weather phenomena pushes forward research on their occurrence and improving our understanding thereof. Supercell thunderstorms are the focus of much severe convective research, as they represent on ...
EPFL2023

The influence of water-saturation on the strength of volcanic rocks and the stability of lava domes

Marie Estelle Solange Violay, Michael Heap

The rocks forming a volcanic edifice or dome are typically saturated or partially-saturated with water. However, most experiments aimed at better understanding the mechanical behaviour of volcanic rocks have been performed on dry samples, and therefore mos ...
2023

An analytical approximation of urban heat and dry islands and their impact on convection triggering

Gabriele Manoli, Kai Wang

It is well known that cities increase air and surface temperatures compared to their rural sur-roundings, the so-called urban heat island (UHI) effect. However, the associated changes in at-mospheric humidity (also known as urban dry island, UDI) and conve ...
ELSEVIER2022
Afficher plus