3107F.2.2 Component Stiffness
Stiffness that takes into account the stress and deformation levels experienced by the component shall be used. Nonlinear load-deformation relations shall be used to represent the component load-deformation response. However, in lieu of using nonlinear methods to establish the stiffness and moment curvature relation of structural components, the equations of Table 31F-7-3 may be used to approximate the effective elastic stiffness, EIe, for lateral analyses (see Section 3107F.5 for definition of symbols).
|Reinforced Pile||0.3 + N/(f'cAg)|
|Pile/Deck Dowel Connection1||0.3 + N/(f'cAg)|
|Prestressed Pile1||0.6 < EIe/EIg < 0.75|
|Concrete w/Steel Casing|
- The pile/deck connection and prestressed pile may also be approximated as one member with an average stiffness of 0.42 EIe/EIg (Ferritto et al, 1999 [7.2])
N = is the axial load level.
Es = Young's modulus for steel
Is = Moment of inertia for steel section
Ec = Young's modulus for concrete
Ic = Moment of inertia for uncracked concrete section