Dynamic modeling and sensitivity analysis of tunnel boring of the whole section system to manage tunnel projects

Today, the use of tunnel boring machines to drill long tunnels under different geological conditions has become widespread. On the other hand, in tunnel projects, especially subway projects, the situation of tunnel boring due to time consuming and high cost, determines the main strategy of the project. In this research, using a systemic approach, the dynamic relationship of the factor affected by tunnel boring machines in tunnel projects has been investigated and analyzed.The system in this model includes three subsystems for the production of precast concrete parts, tunnel boring machine and the process of discharging drilling materials, in this model, the data obtained from two TBM machines in a period of 3 years have been used.The simulation results show the effect of tunnel boring character from factors such as drilling diameter, production rate of precast concrete parts, discharge rate of drilling pool and various problems. Finally, the model is validated and sensitivity analysis is performed on the model.According to the initial input numbers of the model, the quantitative results of the model indicate that if the production rate of precast concrete parts is reduced from 12 to 7 per day, tunnel boring will be completed 40 days later and If the number of shifts of tunnel boring machines changes from 2 shifts to one shift per day, the drilling time will increase from 397 days to 823 days.By changing the number of shifts from 2 to 3 tunnel boring shifts per day and increasing the number of mud trucks serviced from 55 to 75 services, the time required for tunnel boring will be reduced from 397 days to 277 days.Considering the general inclusion of the model for all tunnel boring systems, by changing each of the independent variables of the model and defining different scenarios, the best possible result can be achieved for project management and project strategies can be developed based on it.