Comparative Study on Grouting Protection Schemes for Shield Tunneling to Adjacent Viaduct Piles

Shield tunnels will inevitably pass through viaduct piles at a close distance due to the extensive construction of subways and viaducts in city. In order understand influence shield tunneling on deformation existing pile foundation grouting protection measures, based an engineering case, Changsha Metro Line 5 (from South Gaoqiao station Guitang station), three-dimensional finite element model was established analyze bridge using wall with different depths shapes when tunnel is under construction. The analytical results indicate that can effectively reduce displacement; especially depth 3 m below bottom tunnel. Moreover, L-shaped longitudinal displacement piles. present findings may provide reference for design passing