DESIGN SPECIFICATIONS FOR HIGHWAY BRIDGES - IISEE

16.5 Excessive Displacement Stopper
(1) For the following bridges excessive displacement stoppers working in the
perpendicular direction to the bridge axis, shall be installed in the girder-end
supports, in addition to the unseating prevention system working in the longitudinal
direction to the bridge axis.
1) Skew bridges with a small skew angle meeting Equation (16.5.1)
sin 2θ/2 > b / L ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ (16.5.1)
where
L: Length of a continuous superstructure (m)
B: Whole width of the superstructure (m)
θ: Skew angle (degree)
2) Curved bridges satisfying Equation (16.5.2)
115 1
cos
> b / L ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ (16.5.2)
1 cos
where
L: Length of a continuous superstructure (m)
B: Whole width of the superstructure (m)
φ: Fan-shaped angle (degree)
3) Bridges with narrow substructure crown in the bridge axis direction
4) Bridges with a small number of bearing supports on a substructure
5) Bridges with piers likely to move in the perpendicular direction to the bridge axis as
a result of liquefaction-induced ground flow specified in Section 8.3.
(2) Bridges specified in 3), 4) and 5) of the above (1) shall have excessive displacement
stoppers installed at intermediate supports.
(3) Excessive displacement stoppers in the perpendicular direction to the bridge axis
shall be designed in accordance with the provisions in Section 15.5.
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