ABSTRACT
Design and construction of shallow tunnels is a challenging aspect of urban tunnel construction. Current study details the design and construction of a large diameter tunnel underneath a very low overburden of underneath existing major utilities, including water/gas pipelines and operational road, for India’s first High Speed Rail Project. The study details the aspects of design and construction undertaken using the New Austrian Tunneling Method (NATM) along with the pre-support measures considered. The study details the design aspects associated with the tunnel stability, without and with the pre-support measures, using the project case study of Mumbai Ahmedabad High Speed Rail Project. Study further validates the findings and compares it with field observations. Based on the undertaken analysis, study confirms and apprises the application of NATM with umbrella arch method for large diameter tunneling in shallow ground conditions.
