Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Quarterly Journal of Engineering Geology & Hydrogeology

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Warren, C.D. Articles by Mortimore, R.N. Search for Related Content GeoRef GeoRef Citation

Chalk engineering geology – Channel Tunnel Rail Link and North Downs Tunnel

¹ 1Halcrow Group & Rail Link Engineering,Vineyard House, 44 Brook Green, Hammersmith, London, W6 7BY, UK
² 2Applied Geology Research Unit,School of the Environment, University of Brighton, Cockcroft Building, Moulsecoomb, Brighton, BN2 4GJ, UK

Agreat part of the Channel Tunnel Rail Link (CTRL) is constructed through the Chalk and the ground investigation for the CTRL has yielded a mass of new information on allaspects of the Chalk. A precise bed by bed lithostratigraphy obtained from cored boreholes has aided engineering description, classification, decision making on design of machines and construction methods/specifications. Correlation of Chalk marker beds between boreholes drilled for the tunnels beneath London illustrated the influence of sub-Tertiary erosion and of faulting onpreservation of different stratigraphic levels in the Chalk. These different stratigraphic levels affect materials through which the tunnels will be constructed andconsequently tunnel vertical alignment or choice of construction method. The marker bed stratigraphy in the Thames Tunnel boreholes has enabled the same stratigraphic levels to be identified in local quarries and detailed analyses to be carried out for the design of Tunnel Boring Machines. Using individual marker beds, a detailed ground profile was constructed for the North Downs Tunnel which allowed fault zones to be predicted accurately and the different rock mass character of the Chalk formations to be delimited for numerical modelling, design zones and construction monitoring. The project also provided the opportunity to evaluate the CIRIA Chalk Grading scheme.

Key Words: chalk • engineering properties • railroads • tunnels

This article has been cited by other articles:

				C.N. Edmonds Karst and mining geohazards with particular reference to the Chalk outcrop, England Quarterly Journal of Engineering Geology and Hydrogeology, August 1, 2008; 41(3): 261 - 278. [Abstract] [Full Text] [PDF]