Analysis of NATM tunneling method using CYCLONE modeling and simulation tools

The NATM or New Austrian Tunneling Method became a popular method for tunneling in Indonesia recently, since at least two strategic and huge construction projects utilized it. It is considered as a new method introduced to the Indonesian construction industry and therefore it is interesting to be studied and anticipated for the implementation. This paper discusses modeling the operation of the NATM and then simulation of the model for finding the productivity, effectiveness, and problems that may come in the implementation. The CYCLONE modeling and three simulation tools, i.e., WebCYCLONE, COST, and Symphony.Net, were utilized for this purpose. Data used for durations of tasks associated with the method were gathered from previous work in the field of different projects and literature. The results of this analysis then compared to other similar analyses but for a different project. A comparison of those two analyses was used to identify the most important tasks that will determine the performance of the method with a safety-first requirement in mind. The sensitivity analysis identified secondary resources such as a concrete wet sprayer; the shotcrete team and the formwork team are considered sensitive to improve the performance of the NATM.