SPATIAL MANAGEMENT OF GEOTECHNICAL DATA FOR SITE SELECTION

A ground characterisation exercise was conducted in order to identify sites suitable for a blast furnace at the Redcar steelworks in northea st England. The purpose of this exercise, conducted some 20 years afte r the investigations were carried out and a decade after the steelwork s had been constructed, was to develop techniques for managing spatial data using Geographical Information Systems (GIS) and geostatistics. Borehole details, from the factual site investigation reports, were en tered into a database using a relational structure with linked files. The borehole location and lithology files were keyed in using codes fo r geological material, weathering grade, strength, borehole type and v erification status. Laboratory and field test data were input by scann ing tables in the ground investigation reports and processing the scan ned images using optical character recognition software. The XBase pro gramming language was used to execute graphing, GIS and geostatistics programs; thereby enabling repetitive tasks to be carried out by the c omputer. This both saved time and reduced errors and inconsistencies t hat could result from repeated manual execution of the same program. S ome simple spatial operations could also be carried out entirely from within dBase, an example being the use of moving-window statistics emp loying rectangular windows aligned parallel to the axes of the coordin ate system to study local stationarity. GIS have been found to offer a n effective tool for analysing, querying and presenting spatial site i nvestigation information. Geostatistical kriging and simulation techni ques offer powerful spatial modelling tools for creating visualisation s of the spatial variability of parameters measured at points during a ground investigation. The Redcar case history demonstrates how a data base management system (DBMS) can be used to manipulate site investiga tion data as part of a modelling and interpretation exercise. DBase so urce code allows others to follow the same path or build upon the foun dations herein. (C) 1998 Elsevier Science B.V. All rights reserved.