Scheduling is of great importance in the planning and management of construction projects. The complex interdependence between construction activities in tunnels affects the construction time and costs to some extent. Ground conditions, construction time and costs are fundamental considerations in decision-making for the planning and design phase of a project. In this paper, the innovative DAT method is applied to probabilistically assess ground conditions, construction time and costs. During construction, real geological data for the excavated sections of the tunnel become available, and geological uncertainties for these sections are completely eliminated. These new data can be used to update the expected geological conditions of the tunnel route in order to achieve more accurate predictions for the unexcavated section. Schedules are major concerns in construction planning and management. The mutual interferences among construction activities of tunnels are complicated, which will affect scheduling to some degree. Ground condition and construction (excavation & support system) time and costs are key factors in decision making during the planning and design phase of a tunnel project.
In this work the DAT innovative methodology for the probabilistic estimation of ground condition and construction time and costs is used. As construction progresses, geologic information is checked based on the excavated part of the tunnel and, therefore, the uncertainty about this part of the tunnel will disappears. This new information can be used to update the geology condition of the tunnel in order to obtain more precise prediction for unexcavated part.
In this paper, an engineering application to Garan road tunnel is well presented to demonstrate how the ground conditions and the construction time and costs are updated during construction. Finally, the results of simulations for the initial prediction and the updated prediction will be compared in order to see how the construction time and costs distributions of the given tunnel are changed after the geologic updating.Finally, reducing of uncertainty about the construction time and costs is resulted. It facilitates both the owners and the contractors to be aware of the risk they should carry before construction of unexcavated part, and it is useful for both tendering and bidding.