Segment Damage and Deformation Pattern Analysis of the Shield Tunnel Squeezed by the Shield Tail

During construction of shield tunnel, there are inevitable tolerances between driving route of shield machine and theoretical design axis of tunnel. Therefore, the segments cannot avoid being squeezed by the shield tail brush even shield shell, which causes damage, cracks, dislocation and leakage in segments. Based on the plastic damage constitutive model of concrete, three-dimension finite element model of shield tunnel which considers squeezing action of shield tail, soil pressure, jacking force and grouting pressure, was established. Segment damage and deformation pattern of shield tunnel under different squeezing position and deflection angle of the shield shell were analyzed. The analysis results indicate that the area squeezed by the shield shell is the most damaged area which deviates from the top of the segment because of stress concentration. The tensile damage mainly occurs in the interior surface. The tensile damage of segments reduces gradually as the squeezing position is closer to the circumferential seam. The damage range gradually increases, but the trend slows down with the deflection angle increasing. The squeezing action of shield shell causes apparently irregular deformation of damaged segmental ring. With the deflection angle becoming larger, the tensile damage of segments is larger, therefore, the convergence deformation is larger. Considering the significant effect of tensile segment damage on the bearing capacity of the tunnel, it is suggested that the effect of shield tail extrusion on the segments should be taken account into the structural design of the shield tunnel.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFF60 Standing Committee on Tunnels and Underground Structures.
• Authors:
  • Yu, Kaiwen
  • Jin, Hao
  • Gong, Quanmei
  • Zhou, Shunhua
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 14p

Subject/Index Terms

• TRT Terms: Analysis; Construction; Deformation; Finite element method; Shields (Tunnels); Tunnels
• Subject Areas: Bridges and other structures; Construction; Transportation (General);

Filing Info

• Accession Number: 01657915
• Record Type: Publication
• Report/Paper Numbers: 18-04300
• Files: TRIS, TRB, ATRI
• Created Date: Jan 25 2018 9:34AM