The possibility of partial failure of large slurry shield-driven tunnels is investigated by an upperbound approach in limit analysis and a three dimensional numerical modeling for the Shanghai Yangtze River Tunnel. The results of the upper-bound limit analysis failure mechanisms and the 3D numerical modeling have shown that the partial blow-out of the upper part of the tunnel face occurs when the slurry pressure is too large while the global collapse of the whole tunnel face occurs when the slurry pressure is too small. The failure mechanisms and critical slurry pressures obtained from both approaches are presented and discussed.