Requirements to Enhance the Decision-Making Process for Tunnel Construction by Virtual Design and Construction (VDC)

This paper discusses requirements to enhance the current decision-making process for tunnel construction, which involves significant uncertainties in ground conditions. In current practice, project managers determine resource-loaded construction schedules based on one specific set of ground conditions. In addition, they do not update ground conditions for unexcavated sections with information from excavated sections. This decision-making process often causes cost overruns, schedule delays, and disputes. To mitigate these problems, managers must make timely and robust decisions about construction schedules, during both the preconstruction and construction phases, in a transparent and integrated manner. To this end, we applied a 4D model-based decision-support system, the Development Strategy Simulator (DSS), to a U.S. tunnel project. Our analysis showed that the DSS was able to simultaneously analyze and represent the construction schedule and the resulting resources. However, we argue that it is still necessary to develop a progress-adaptive stochastic earth model, as well as a formal process for the automatic formulation and evaluation of multiple alternative schedules.