Abstract: Construction schedule rectification is an effective method to ensure the orderly construction of underground hydropower stations against the interference of emergencies, and its process can be effectively simulated using a system dynamics (SD) model. Previous studies lack consideration of rectification strategies adopted in the construction, and the reported SD models failed to consider rectification parameters. This study constructs a SD-DES model by coupling a SD model and a discrete event simulation (DES) model for construction schedule rectification, considering rectification parameters and integrating four sub-models into the SD: overtime, increase in mechanical equipment, increase in construction personnel, and rescheduling. Taking the advantages of the SD and DES models, we simulate and analyze the full procedure of schedule estimation - rectification strategy formulation - strategy implementation effect. Application to a real underground hydropower station project shows that our new model improves significantly the schedule rectification strategy, more superior to the traditional SD model.

Key words: underground hydropower station, schedule rectification, SD model, SD-DES coupling model, rectification parameters