The geotechnical database for the Jubilee Line Extension project

Abstract

As part of London Underground Limited's (LUL's) contribution to the collaborative research project ‘Subsidence damage to buildings: prediction, protection and repair’, a geotechnical database system was developed for storing, straightforwardly retrieving and exporting geotechnical and other construction information. The research was sponsored by the DETR–EPSRC LINK Construction Maintenance and Refurbishment Programme under the project management of CIRIA. The collection and management of the research data was seen, from the start, as one of the key parts of the research, the aim being to create comprehensive case records for immediate and subsequent analysis. The database that was created, however, has a much greater capability and a wider potential applicability. The geotechnical data that were collected related to the several work stages and contracts for the construction of the Jubilee Line Extension project (JLEP). They include research-based data, that is, measurements taken by the research team; construction monitoring that was a JLEP contractual requirement; and construction records of specialist processes (such as compensation grouting); and of the main works of tunnelling and excavation. In addition, reference can be made, via the system, to information stored in a variety of other media, ranging from paper copies to digital videos. The paper considers the questions posed and solutions found for the design of the database system. Some of these questions resulted from the multiplicity of data sources and the lack of a suitable data transfer standard. The basis of data control is geographical, that is, on the project mapping. The format and methods of accessing data are object oriented, for example a survey point, a piezometer, a grout injection port, etc. With the aid of screen-captures, the paper explains and describes the tools that were developed to find, view and export information. The paper also describes how the database is being used on the research project and introduces ideas for its wider adoption as a business tool for LUL. The concluding section defines the key features that have made the system successful and urges the industry to adopt a monitoring data transfer standard.