Very sophisticated, time consuming, and expensive bridge construction. I give both the precast and cast in place workmanship a high mark. Kokosing has good QA on this job.
A lot of expense is in the falsework - for example the temporary steel shores which are in the left hand bay to accept the "Key" stone center precast section. A temporary bridge had to be built over Big Creek to provide access for the cranes to the westerly sections of the Fulton bridge.
This bridge will mirror the historic cast in place conrete bridge which was removed - and aesthetically this may be important over the Metroparks Zoo - but at a considerable dollar cost.
Photos 4.19.09
There are many high tech field applied critical details in this construction system - the following photo shows the post tensioning cable puller (silver cylinder on deck with multiple cable holes) and hydraulic power pack on a temporary personel platform. After the cable bundles (coming out of the black lipped tubes and wrapped in poly) are tensioned and locked down the next step is to pressure grout the cable tube which runs from tower to tower through the 3 precast arched concrete sections. You can read more about post tensioning on Wikipedia [1]
Links:
[1] http://en.wikipedia.org/wiki/Prestressed_concrete