Automatic displacement monitoring data interpretation – the next step towards an expert system for tunneling

For more than twenty years, absolute displacement monitoring has been standard practice for tunneling projects in Europe. By correlating the monitoring results to specific geological conditions, it is now possible to forecast ground conditions ahead and in the vicinity of the tunnel face. To improve this forecasting, 18 characteristic scenarios, wherein transitions from soft to stiff ground occur (and vice versa), have been established and input to a monitoring data correlation matrix. By continuously comparing actual monitoring results to the reference cases in the correlation matrix, the prediction of variations with respect to
ground conditions ahead of the face is greatly facilitated. The monitoring data trends in the correlation matrix are weighted according to their relevance for specific geologic situations, with the most compelling trends yielding the highest weighting factors. An automated monitoring data evaluation tool can be achieved by incorporating the results summarized herein to a computer code. It is believed that such a tool will significantly aid the work of onsite engineers with regard to data evaluation and interpretation activities.