Simulation of NATM Tunneling Construction in Gravel Formation — Lessons Learned from Pakuashan Highway Tunnel Project in Taiwan

Construction processes are complex operations that include the use of equipment, materials, crews and geological conditions. Simulation can be used to study these processes in order to make competent decisions that will lower costs and shorten the duration of the project before it has started. Tunneling is a highly repetitive construction operation and simulation can be used to analyze the process. A model used to simulate the NATM tunneling construction operations for Pakuashan highway tunnel project is developed in this paper. This project is unique because of the soil conditions. A discrete event simulation methodology, CYCLONE, is used to build the operation model and simulate the tunneling processes. Statistical analysis indicates that duration of most tunneling operations can be modeled by Beta probability distribution. Results also show the model predicting the advancement rate of such tunneling project is accurate.