ABSTRACT
To provide a framework for the design of a detailed ground investigation and assess the geotechnical suitability of the location of major elements of a large construction project in Central Saudi Arabia required an investigation of the nature of surface materials and foundation conditions over a remote uninhabited area of 750 km2. In order to complete a study of this size a programme of geotechnical soils mapping was undertaken. Initial desk studies were carried out using standard terrain evaluation techniques to interpret enhanced 1:25,000 scale SPOT and 1:50,000 scale Landsat TM imagery. This was followed by reconnaissance field mapping at the same scale to verify the remote sensing interpretation and provide an overall appraisal of the soils in the area. Selected areas which were to be developed were mapped at 1:10,000 scale by a combination of walkover and driveover surveys. The 1:10,000 scale mapping was used to plan a programme of trial pitting necessary to determine the broad subsurface conditions. The results of the mapping and trial pits were compiled and a series of interpretative maps, cross-sections and accompanying tables were produced which provided details of site geology, geomorphology, flood hazard, ground conditions, excavatability of soils, and material suitability for various construction purposes. These tables, maps and sections formed the basis for more detailed site specific investigations for particular structures and for the general appraisal of aggregate resources on the site.
