August 19, 2005:
A closer look at the removal process
(from Sparky Witte's photos)
The construction of the Pearman Bridge involved both prestressed concrete
girders as well as steel girders. Here are some learning links to
chase your curiosity about what prestressed concrete is all about. In the
photos below - you can see reinforcing bars (rebar) dangling in all directions -
the result of unbuilding a girder.
The Learning Links
With grapples, the girder and the near support cap are more or less
uprooted.
The rebar at the base of the supporting pier is cut
Working on the next girder, a grapple stabilizes the pier while the
shear cleans the girder along its length
The girder is pushed off the supporting cap
and the shear cuts through the residual rebar
leaving only the supporting pier and cap
and another clash of the titans to uproot the pier and cap
