6.0 BRIDGE TYPE, SIZE, & LOCATION
The proposed bridge #42 superstructure will use
inch deep deck bulb tee girders for
foot long single span.
inch decked bulb tee is a WSDOT standard precast prestressed concrete beam.
ete deck for the bridge is cast integrally into the girder reducing construction
time in the field. The girders are held together using weld ties, grouted keyways, and
8 lines of 53 inch girders are required for the 42.40
foot wide br
idge (see Figure 3).
The proposed substructure will have a foundation supported by driven piles or spread
footings. The final foundation type will be determined from a complete geotechnical
study that includes soil borings. The pile driving or drilli
ng will occur outside of the
ordinary high water of Jim Creek.
Jordan Road will not be relocated so the new bridge will be located in nearly the same
location as the existing bridge (refer to Appendix A Exhibits 2 & 3). The new bridge will
be moved about
feet southerly along the alignment to offset each abutment the same
distance from the creek.
The approaches to the new bridge will be raised up to 5 feet over the existing road profile.
Approach at pier 1 will be 34 feet wide adjacent to t
he bridge for a length of 200 feet to
the southwest tapering from the full bridge width to existing road width over a length of
approximately 36 feet (6:1 taper). The southwest approach will be built up with 3:1 fill
slopes to allow for amended storm wate
r treatment. The approach at pier 2 will be 34 feet
wide adjacent to the bridge through the project limits tapering to existing pavement at
approximately sta. 12+20.
It is proposed to build bridge #42 with staged construction since
it is not feasible to close
Jordan Road for the duration of the project. Exhibit 3 graphically depicts the staging for
Temporary / Permanent Approaches
Mobilize; install Erosion Control devices, Land clearing for approaches. Install
temporary channelization and traffic safety devices.
stream portion; Excavate for abutments. Drive piles or spread footings.
Build abutments. Install precast girders. Build wingwalls. Shore and build up
approaches. Pave new
road, reroute traffic to new upstream portion of bridge.
Excavate stormwater facilities.
Demolish / remove old bridge.
New Bridge / Mitigation
stream portion. Build driveway realignments. Construct stormwater swales
and infiltration systems. Complete mitigation for impacts.