Dat modifications and its application in large-scale cavern construction

The Decision Aids for Tunneling (DAT) have been used world-wide in underground construction projects as a risk assessment tool. However, compared to the linear tunnel construction, underground cavern construction projects involve higher construction risks due to larger sizes and more complex tunnel networks. Therefore, it is useful to examine the capability of the DAT in simulating underground cavern construction with complex networks. This paper discusses the applicability of the modified DAT technique to real construction situation by considering a large scale underground cavern construction. The results show that the overall construction time obtained from the DAT analysis is comparable with the scheduled construction time proposed by the contractor. Time-cost scattergrams for the three partial face excavation scenarios are plotted and a final prediction on the construction time/cost is made. Finally, a parametric study is conducted by increasing the number of simultaneous cavern excavations in order to optimize the resource allocation on the construction site. The overall construction time was found to decrease exponentially with increase in number of simultaneous cavern excavations. The results show that the DAT is a valuable tool in predicting construction parameters and managing resources for underground cavern projects. (C) 2015 Elsevier Ltd. All rights reserved.