DESIGN SPECIFICATIONS FOR HIGHWAY BRIDGES - IISEE

height from the bottom of the pier to the height of inertia force of the
superstructure.
Table 6.4.3 Equivalent Weight Calculation Coefficient, cp
Bending Failure, or Shear
Failure after Flexural Yielding
Shear Failure
0.5 1.0
(2) Verification of Seismic Performance Level 3
Reinforced Concrete single column piers and Reinforced Concrete single-story
rigid-frame piers, shall be verified in according with Equation (6.4.6)
6.4.7 Performance Verification for Pier Foundations
(1) Pier foundations shall be verified according to their structural types. Responses of
foundations subjected to loads described in (2) shall satisfy the conditions specified
in (3).
(2) When responses of the piers reach the plastic ranges, the dead loads plus the
inertia forces obtained by the design horizontal seismic coefficient in Equation
(6.4.11), shall be considered as design loads. When responses of the piers remain
within the elastic ranges, the sectional force at the pier bases shall be considered as
design loads.
k hp = c dF Pu /W ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ (6.4.11)
where
k hp : Design horizontal seismic coefficient used in the verification of pier
foundations based on the ductility design method (rounded to two decimals)
c dF : Modification factor used in calculation of the design lateral coefficient for pier
foundations based on the ductility design method (rounded to two decimals)
Pu : Lateral strength (kN) of the pier supported by the foundation. For Reinforced
Concrete Columns, Pu shall be calculated by referring to Section 10.3.
However, in case of shear failure according to the provisions of Section 10.2,
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