An Improved Numerical Model of Shield Tunnel with Double Lining and Its Applications

Table 1

Comparison of elements between improved model and existing models.

Items	Segment lining and secondary lining	Segment lining joint	Junction surface	Contact surface
Model I	Beam element	Spring elements with functions of tension and compression, shear, and bending resistance	Fixed radial beam element	Radial and tangential spring elements with functions of tension and compression resistance
Model II	Beam element	Spring elements with functions of tension and compression, shear, and bending resistance	Radial and tangential spring elements with function of tension and compression resistance	Radial and tangential spring elements with functions of tension and compression resistance
Model III	Beam element	Spring elements with functions of tension and compression, shear, and bending resistance	Friction elements	Radial and tangential spring elements with functions of tension and compression resistance
Improved model	Beam element	Spring elements of node displacement coupling with functions of tension and compression, shear, and bending resistance	Radial compression bar with functions of compression resistance and tangential spring with coupling functions of elements node displacement	Radial compression bar with functions of compression resistance and tangential spring element