Integral bridges - Computational Analysis and Design of Bridge Structures - page 492

Figure 16.1 Integral pier on ramp FR - A over SR6060, Pittsburgh, Pennsylvania.

E FF EE F F E

F EE F EE F

E E F E E

F F F F F

Figure 16.2 Possible configurations for a typical four - span highway bridges.

bridge. However, unlike traditional bridges that sit on bearings with heavy
abutments, integral bridges can be formed by casting the deck integrally
with short abutments supported on a single row of flexible piles (Figure 16.3)
to take care of the longitudinal thermal movement of the bridge.
IABs are designed without any expansion joints in the bridge deck.
These bridges are generally designed with stiffness and flexibility spread
throughout the structure-soil system so that all supports accommodate the
thermal and braking loads. They are single- or multiple-span bridges that
have their superstructure cast integrally with their substructure. Generally,
these bridges include capped pile stub abutments. Piers for IABs may be
constructed either integrally with or independently of the superstructure.
Integral or semi-integral bridges are defined as single- or multiple-span con-
tinuous bridges with rigid, nonintegral foundations and movement systems
primarily composed of integral-end diaphragms, compressible backfill,
and movable bearings in a horizontal joint at the superstructure-abutment
interface (Wasserman and Walker 1996).