Welcome to another Issue of Geotechnical Engineering.
Two words dominate much of civil engineering at the moment: ‘infrastructure’ and ‘sustainability’. While a glance at many publications readily shows the extent to which infrastructure projects involve a very substantial geotechnical engineering input, the sustainability debate has largely featured the advances made in building engineering. I believe this is about to change as we realise the enormous contribution geotechnical engineering can make to sustainable construction. Not surprisingly therefore, several of the papers in this issue concern these two topics.
Papers
The largest current construction project in the UK is the Channel Tunnel Rail Link. While much has already been written about it, our first paper, by Phear, Patterson and Warren, focuses on the importance of minimising both waste material and environmental impact; soil from the CTRL tunnelling operation was recycled as fill in a nearby motorway scheme. The paper also highlights the close co-operation between parties that so helps to deliver a successful project.
Tunnelling is enjoying great attention at present; not all of it welcomed after the recent, unexpected subsidence above the tunnelling work for Section 2 of the CTRL project; this tunnelling passes very close to existing London Underground running tunnels. Of interest, therefore, should be Thusyanthan and Madabhushi's model study of the influence of dynamic loading on tunnel linings of dissimilar materials.
Geotechnical engineers have long sought an effective means for detecting the incipient failure of slopes. One such technique–the use of acoustic emission–is presented by Dixon, Hill and Kavanagh who have studied the response of active waveguides in the laboratory and have monitored slopes in the field to explore a relationship between acoustic emission and slope deformation rate.
Returning to tunnelling, this time in Greece, Georgiannou describes the highly variable ground conditions encountered in the north-west of the country where the complex geology changes very rapidly owing to substantial tectonic activity. Sudden changes in conditions make for difficult tunnel construction.
Finally, Al-Shayea et al present the results of an extensive testing programme to determine parameters for three soil types in the Eastern Province of Saudi Arabia, that are suitable for use in non-linear constitutive models of behaviour.
