3-D finite element analysis of post-prestressed concrete lining

Post-prestressed concrete lining is a new type of pressure tunnel lining. The key for its finite element method (FEM) analysis is how to simulate the friction loss and the nonuniform distribution of prestress force in the circle tendons. An equivalent stress method based on the ANSYS is proposed, and it simulates the nonuniform prestress of curved tendon by normal equivalent stress and tangent equivalent stress, which were exerted on the SURF154 elements. FEM analysis was made of a concrete tunnel lining post-prestressed with double-looped unbonded tendons. The calculated results agree well with the in situ measured results. The proposed method is also applicable to the FEM analysis of concrete structures such as bridges post-prestressed with uncoated curve tendons.