ABSTRACT
Mumbai Metro Line 3 (Line 3) is one of the unique and most challenging ongoing underground metro works in India. The project covers the approximately 33.5km long underground metro rail system running from Cuffe Parade Station in the south of Mumbai to the Seepz station at the northern end with 26 underground stations and associated tunnels. The construction of Line 3 is divided in 7 contract packages. The fully underground MML3 project comprises mixed ground condition of various weathering grade of rock throughout the tunneling stretch. Out of 26 underground stations 7 stations are constructed with combination of cut & cover boxes and conventional tunneling. In this project there are 3 crossovers, stabling tunnels at two stations and 88 cross passages connecting the bored tunnels which are constructed conventionally. In this paper, few very crucial challenges faced during design and construction of conventional tunneling are discussed. At present, 90-95% of conventional tunneling is successfully completed and remaining to be accomplished soon.
