Combining the CSM2020 discrete event simulation model with Decision Aid in Tunneling (DAT) to develop a robust approach for the estimation of completion time for TBM tunnels

Abstract

The Decision Aids in Tunneling (DAT) are a tool that help in the decision-making process regarding the uncertainty in the project plan, alignment alternatives, and other project aspects. One of the important input parameters in the DAT is the advance rate, and its accurate estimation can significantly improve the accuracy of the DAT. The advance rate values comprise an accurate estimation of the rate of penetration and machine utilization. A few models have been proposed to estimate utilization with different levels of accuracy. The CSM2020, which is a discrete event simulation-based model has proven to be a promising utilization estimation as it incorporates the uncertainties in various tunneling activities in the determination of the delays during the tunneling and in the estimation of machine utilization. In the present study, project data were analyzed, and utilization values were estimated using the CSM2020 model. The results from the CSM2020 model were set as input in the DAT and the average completion time was compared with the actual site data. The results from other available prediction models were also assessed, and a comparison was made with the actual data. The incorporation of CSM2020 results into the DAT showed that the overall difference in completion time was 1.3% compared to the actual project data. Hence, a combination of CSM2020 and DAT can be considered an effective approach that incorporates the uncertainties in the various tunnel operations thereby offering a more accurate and reasonable estimation of completion time for mechanized tunnels.