TBM tunneling challenges in Kanpur Metro: Old brick sewer at <0.5D cover

The Kanpur Underground Metro project faces challenges in a densely populated area with old buildings and aging brick sewer lines at shallow depths. Relocating these sewer lines was impractical, so the Tunnel Boring Machine (TBM) must pass beneath them. The area’s alluvial soil includes clay, silt, gravel, and sand, with a groundwater table 27m deep. To assess the impact of TBM tunneling, particularly where the TBM cover is under 3m, a two-dimensional Finite Element Analysis (FEM) was performed using PLAXIS 2D software. This paper presents a thorough analysis and proposes safe construction methods for TBM tunneling in these challenging conditions. The FEM results are validated through real-time data from on-site monitoring instrument.