Geomodels in Engineering Geology ebook is available to be downloaded here now.
- Title: Geomodels in Engineering Geology
- Author: Peter Fookes, Geoff Pettifer, Tony Waltham
- Publisher: Whittles Publishing
- Pages: 209
The preparation of each pictorial block diagram in this book typically began with a conceptual discussion, followed by an examination of maps, the published literature, photographs and the development of a sketch model based on experience. This was then reviewed. The final diagrams were produced manually by placing a sheet of tracing paper on a template and, using a soft pencil, drawing a block outline from an arbitrary viewpoint to cover the area of interest and important locations.
Approximate distances were estimated along the horizontal axes of the block, the topography was sketched using an appropriate vertical exaggeration and the surface drainage was added. The underlying stratigraphy and geological structure were then added, the probable groundwater conditions assessed and adjustments were made to highlight important landforms. Finally, the lines were inked in, the pencil work erased, the key features emphasized and labelled and captions added. Layers of colour were then applied by crayon on a good paper copy.
It is not suggested that this method is followed during a ground investigation to produce site geomodels, but the same procedures can be used to produce block diagrams for important engineering projects. These would also incorporate specific information from ground investigations, satellite images and site reconnaissance mapping. Site models (ground models) are primarily intended to aid site evaluation and engineering decision-making, but they can also be used to inform a wider non-specialist audience. Larger scale block geomodels covering small areas may be useful in illustrating how specific landscape features have evolved, or are expected to evolve, to update knowledge of ground conditions as more data become available, or to help solve specific problems arising during investigation and construction.
The production of such diagrams is a time-consuming process. Software packages can now be used to produce the basic block outline and topography, but an interpretation of the ‘total geology’ generally has to be built up using freehand methods. It is therefore likely that for the time being ‘traditional’ field maps, sketches and cross-sections will continue to be the most practical form of geomodels for smaller projects.