APPLICATION OF 3D GEOLOGICAL MODELS WITH EXAMPLES FROM LONDON AND GLASGOW

The digitisation of boreholes, maps and other geoscientific data within the British Geological Survey (BGS) has facilitated a change from the traditional 2D paper map to a 3D attributed geological model. It is now possible to construct models of the shallow sub-surface, that not only predict the type of rocks that lie beneath our feet, but also their engineering properties (rock strength, shrink-swell characteristics and compressibility) and hydrological properties (permeability, porosity or thickness of the unsaturated zone). The data can then be imported into standard Geographical Information Systems (GIS) packages, resulting in a powerful tool to assist in strategic planning and sustainable development.

Currently BGS is constructing high-resolution 3D models for the Thames Gateway development zone (London) and the Clyde Gateway (Glasgow). Both of these areas have been targeted for large-scale urban regeneration. The Clyde Gateway area of central Glasgow is set aside for new houses, road extensions, industrial outlets and a stadium for the Commonwealth Games 2014 bid. The Thames Gateway development zone is currently the biggest building programme in the UK. 160,000 new homes will be built, with over 180,000 new jobs created. The area will also host the 2012 Olympics in the Lower Lea Valley (London).

In both the Thames and Clyde Gateway extensive areas of difficult ground, including soft soils, high groundwater levels, and contaminated sites occur. Failure to appreciate the geological ground conditions fully can be costly. Detailed 3D geological models have been developed at 1:10 000 scale for both areas to help make effective decisions. The models are being used to aid the planning and design of the ground investigation work by highlighting areas where the geology of the site could cause problems during construction.