ABSTRACT
This paper discusses the construction of the L2 subway station of Esfahan subway line 2 using combined tunnelling methods in the historical part of city of Esfahan, which is one of the oldest cities in Iran with many historical landmarks. The challenges, potential risks, and proposed solutions for determining an appropriate tunneling method are presented, along with introduction to an innovative three-story station design to accommodate an interchange station with metro line 1 and addressing high groundwater levels due to close proximity to Zayandeh-Rood river. Construction processes had to be conducted underground due to compliance with cultural heritage regulations, requiring creative solutions, which was accomplished by introducing an innovative geometric design and construction sequence. The successful implementation of the project was achieved through a combination of tunnelling methods, braced secant piles, diagonal struts, and the top-down technique. This project serves as a successful case study in constructing underground spaces within historical areas and challenging ground conditions.
