A Multi-Layer Blowout Model for the Tunneling Face Stability Analysis

The stability of the tunnel face during tunneling is one major criteria for design and construction tunnel. Collapse blowout are two modes failure excavation. cover-to-diameter ratio main parameters controlling these modes. Several analytical solutions have been proposed to estimate range support pressure applied on avoid both collapse blowout. However, most those models deal with homogeneous soils. This paper aims at proposing an model predict a in multi-layered derivation based limit equilibrium analysis, which considers water tCiable. validated against real data reported from Second Heinenoord Tunnel project Netherlands. Then, maximum exerted predicted as function ratio, diameter, table level five representative Finally, underground segment Hanoi Metro Line 3 (in Vietnam) show role multi-layer aspect.