Construction schedule simulation of a diversion tunnel based on the optimized ventilation time.

Area of Science:

• Civil Engineering
• Computational Fluid Dynamics
• Environmental Engineering

Background:

• Traditional construction schedule simulations rely on empirical methods for estimating ventilation time.
• Real-world construction schedules are influenced by numerous factors affecting ventilation duration.
• Accurate ventilation time estimation is crucial for efficient underground construction planning.

Purpose of the Study:

• To develop and validate 3D unsteady quasi-single phase models for optimizing ventilation time in tunnels.
• To investigate the impact of various physical phenomena (buoyancy, drag, lift, virtual mass) on contaminant transport.
• To integrate optimized ventilation time into a GIS-based dynamic visual simulation for construction processes.

Main Methods:

• Development of 3D unsteady quasi-single phase models incorporating buoyancy for CO transport and inter-phase forces for dust transport.
• Validation of the airflow model using experimental data from a diversion tunnel.
• Application of the models to a case study of the XinTangfang power station diversion tunnel in China.
• Presentation of a GIS-based dynamic visual simulation method combining network simulation, system simulation, and optimization.

Main Results:

• The proposed model accurately predicts airflow, validated against experimental data.
• Analysis of airflow, carbon monoxide (CO), and dust distributions within the diversion tunnel.
• Demonstration of the integration of optimized ventilation time into a comprehensive construction schedule simulation.
• Successful application to a real-world underground construction project.

Conclusions:

• The 3D unsteady quasi-single phase models provide a more accurate approach to optimizing ventilation time compared to empirical methods.
• The study highlights the importance of considering multiple physical factors in ventilation and contaminant transport modeling.
• The integrated GIS-based simulation method offers a powerful tool for dynamic visualization and optimization of underground construction schedules.