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

Table 8

The bending moments extreme values under different thicknesses of secondary lining.

Thickness of secondary lining (cm)	10	20	30	40	50
Thickness of double lining (cm)	60	70	80	90	100
The increase ratio of double lining thickness	100%	117%	133%	150%	167%
The section of maximum bending moment of the double lining
Bending moment of double lining (kN·m)	146.689	147.398	148.896	150.660	151.945
Bending moment of segment lining at the corresponding section (kN·m)	145.480	138.001	120.650	94.474	72.271
The allocation proportion of bending moment of segment lining	99%	94%	81%	62%	48%
The increase ratio of bending moment of double lining	100%	100%	102%	103%	104%
The section of minimum bending moment of the double lining
Bending moment of double lining (kN·m)	−177.101	−177.886	−179.542	−181.469	−182.814
Bending moment of segment lining at the corresponding section (kN·m)	−175.650	−166.640	−145.771	−116.662	−87.462
The allocation proportion of bending moment of segment lining	99%	94%	81%	64%	48%
The increase ratio of bending moment of double lining	100%	100%	101%	102%	103%