An analysis is made of seepage forces around shield under river by finite differential method and the stability factor of workface with regard to seepage effects is deduced. The computation results show that the pore water pressure will redistribute in sandy soils around the shield tunnel after excavation and the contour lines of the pore water pressure exhibit sphenoid shape. The pore water pressure changes severely at the excavation face. The contour lines of the total water head display circularly around the excavation face of the tunnel and the maximum value of the .seepage forces exists on the excavation face and shield tail. The stability factor of tunnel face decreases due to the existence ofseepage forces, but the slurry pressure in the shield cabinet benefits the face stability. The results also show that the whole shield head will be trapped in the sharply changing zone of pore water pressure and severe consequences will arise if leakage occurs at the shield tail.
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LIAO Shaoming, YU Yan, CHENG Zhigao. Effect of Shield Sealing on Stability of Workface and Seepage Field Around Shield[J].同济大学学报(自然科学版),2008,36(2):172~177192