Development of an expert system for the interpretation of displacement monitoring data / Entwicklung eines Expertensystems für die Interpretation von Verschiebungsmessdaten

Displacement monitoring has been common practice during tunnel excavation for many decades. The results are usually used to assess the stabilisation process and to adapt excavation and support to the actual conditions. Although monitoring is done routinely on practically all sites, no consistent collection of case histories has yet been established, so the experience gained on completed projects is rarely available for new projects. To better utilise this previous experience, an expert system for the evaluation and interpretation of displacement monitoring data is currently under development. The main component of the system is an expert knowledge base containing normal displacement behaviour for a wide range of geotechnical conditions. Methods required for the identification of such normal displacement situations as well as for clear description of the displacement characteristics have been developed and will be outlined. The check whether the actually observed displacements are normal will be done by means of a comparison with a real displacement scenario from the database. In case a significant deviation is identified, the actual displacement trends will be compared to reference trends characteristic for changing ground conditions and the most probable situation determined. If the degree of correlation is low, then it is very probable that the actual displacements show abnormal behaviour.