This section will gather the boundary conditions of the superstructure that are controlled by bearings.
Bearings play a critical role in transferring forces from the superstructure to the substructure while accommodating relative movement. Various actions cause displacements and rotations at supports, including temperature changes (uniform and temperature difference), shrinkage of concrete deck slab, permanent actions (dead loads and superimposed dead loads), variable actions (primarily traffic loads), vertical loads, settlement of supports, and accidental actions such as vehicular collision. Movements can be either permanent (irreversible) or transient (reversible).
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