INSITU TESTS FOR ASSESSMENT OF TRACKBED QUALITY & PERFORMANCE

Trackbed quality and performance are governed by geotechnical processes and considerations. Invariably, the characteristics of the ballast, sub-ballast and sub-grade influencing these processes are highly variable beneath any section of track. Despite the acceptance of this variability, the rail industry tends to adopt methods of investigation which provide only a limited understanding of the extent of the problem. Trackbed designed on poor quality data will inevitably prove to be expensive. If over designed, the overspend will be up front, if under designed the overspend will occur throughout the lifetime of the track in terms of remediation measures. This paper presents the authors' experience of the use of high quality insitu test data for optimising trackbed quality and design. For the covering abstract see ITRD E123761.