In site appraisal the first aspect of the ground to be encountered is its geomorphology.Construction records show that the Quaternary geology of the site usually plays a major to dominant role.Yet our courses for civil engineers and, to a large extent engineering geologists, generally include little or no geomorphology and only a very abbreviated introduction to the engineering geology of the Quaternary.
As these two disciplines are the key to showing the relevance of engineering geology to civil engineering, this is a serious flaw in our system of education and training.It is probable that a majority of several generations of civil engineers have entered the profession with a negative attitude to engineering geology, particularly of the Quaternary, and no awareness of geomorphology.
The dire consequences of such an attitude can be imagined.They may explain in part a widespread reluctance to give proper weight to site investigation matters, a common prejudice against qualitative approaches and an all too frequent failure to contact geologists and geomorphologists with prior knowledge of a site.In addition, they have undoubtedly contributed to our patchy record in the construction of earthworks across clayey slopes.
This unsatisfactory state of affairs is the result of historical chance, springing from events in the 19th century.By the latter part of that century, British geologists, originally of all-embracing interests, became increasingly absorbed with the older rocks and largely abandoned both Quaternary geology and geomorphology.
Unfortunately these attitudes have persisted and, with a few exceptions, are still reflected to a considerable extent in geology departments.As civil engineering departments have naturally relied upon geology departments for teaching in this area, they have, all too often, been supplied unwittingly with courses that have been deficient in the above two respects.
These two gaps have been filled predominantly by geographers.For Quaternary geology this, and the lack of interest of our own profession, is illustrated by the membership of the Quaternary Research Association: in 1999,58% of its members were geographers,21% geologists and 2% civil engineers.As civil engineering departments have essentially no contact with geography, these developments have passed largely unnoticed.
In the profession, performance in this area can be described as uneven.On the one hand the best firms have long realised and embraced the points made here and done first-class work.For instance, we have been confident enough to route our end of the Channel Tunnel through a large old landslide.
On the other hand, during the period 1960-1987, the available case records show a failure rate of 12 out of 18 for the construction of earthworks on clayey slopes and subsequently each year brought further such problems, with time and financial over-runs.
Faced with serious deficiencies in our education and training system identified above, what can be done to improve matters?
Education is paramount.As Glossop (1968) put it: 'If you do not know what you should be looking for in a site investigation, you are not likely to find much of value.'
The profession should take the lead in actively promoting the necessary courses, not wait for the universities to do so.
There is an urgent need to introduce some basic applied geomorphology into existing engineering geology courses, including appropriate field mapping and the use of remote sensing, and generally to re-integrate these two subjects.
A much fuller treatment of Quaternary engineering geology is required.
Provision should be made for the detailed study of case records in relation to geomorphology, Quaternary engineering geology and the Influence Line Statements made or opinions expressed in G ENGINEERING do not necessarily reflect the views of the BGA.
approach to slope stabilisation.Teaching time needs to be expanded to accommodate this and the other changes noted.
To provide the necessary authority and enthusiasm, the teaching should, as far as possible, be done by professionals experienced in site appraisal.
Better use should be made, in teaching and in desk studies, of computerised databases.
Qualitative and quantitative knowledge should be regarded as of equal worth, the qualitative steps often being needed before the quantitative ones can safely be taken.
It is fervently hoped that the profession will rise to these challenges.Not only will this result in a major improvement in our treatment of ground problems, but it will also generate enthusiasm, increase confidence and broaden horizons in the field of engineering geology generally, so that we will be better placed to tackle the major environmental problems which beset us.
John Hutchinson is Emeritus Professor of Engineering Geomorphology at Imperial College, London.This is a brief resume of the Fourth Glossop Lecture, 'Reading the ground: morphology and geology in site appraisal'by J N Hutchinson (2001), Quarterly Journal of Engineering Geology & Hydrogeology,34,7-50.