A Novel Excavation and Construction Method for an Extra-Long Underwater Tunnel in Soft Soils

Table 3

Constitutive parameters of retaining structures.

Structure type	EA (kN/m)	EI (kN m^2/m)		W (kN/m^2)
Steel sheet piles	4.8 × 10^7	2.5 × 10^5	0.25	20
Bored piles	7.5 × 10^6	4.0 × 10^5	0.2	24
Cut-off walls	6.5 × 10^6	5.5 × 10^5	0.2	24
Cement mixed piles	7.0 × 10^6	—	—	24
Steel strut	2.0 × 10^7	—	—	—
Reinforced concrete	3.5 × 10^7	—	—	—
Floor slab	6.0 × 10^6	4.0 × 10^4	0.2	24

Note: EA = axial stiffness; EI = bending stiffness; W = weight;  = Poisson’s ratio.