This item consists of the construction,
maintenance, and subsequent removal of a temporary bridge or culvert for
maintaining traffic.
The waterway opening
generally should be not less than 75 percent of the effective waterway of the
proposed structure based on the 5-year water level. The deck of a bridge must have at least a
23-foot (7.0 m) clear roadway, and if pedestrian facilities existed, at least a
4-foot (1.2 m) wide sidewalk must be provided.
The proposed working drawing
should be reviewed in the District for accuracy of existing features not shown
on the project plans. If the proposed
waterway is less than 75 percent, comments regarding local knowledge of stream
fluctuations will be helpful. In lieu of
a bridge, a pipe culvert or multiple pipe culverts with required waterway, may
meet the requirements for a bridge and will be considered when submitted.
Submit construction working
drawings in accordance with 501.05.
All stress-carrying materials
to be used in any temporary structure must be carefully examined since used
materials generally are employed and may not possess the physical properties
considered in the design. Timber
elements must be examined for specified size and soundness. Steel members must be examined for holes and
alterations that would reduce their section modules. Welded splices in members are not cause for
rejection providing the welds have been made properly and are free from
defects. Existing welded butt splices
must be subject to radiographic inspection.
Approved welders using approved welding consumables should perform
welding. Hardware and miscellaneous materials must be as specified on the
submitted plan.
Piles must be driven in
accordance with 507. The bearing capacity of each pile must be as
specified on the submitted plan, but in no case, less than 12 tons (107 kn). If piles are not driven to bedrock, the
Contractor is responsible for performing the dynamic load necessary to
determine the required blow count.
Construction of the temporary
structure must be according to details and notes shown on the submitted working
drawing. Proposed substitution of
elements of equal or greater strength may be made. All other proposed substitutions or changes
in design must be submitted in an amended working drawing meeting the
requirements of 501.05.
When the plans permit the use
of an existing superstructure as part of a temporary run-around, the bridge
shall be relocated so there will be no reduction in load carrying
capacity. The working drawings for
temporary substructure units must be submitted in accordance with 501.05.
The Contractor is required to
maintain the temporary structure in good condition with respect to safety, ride
quality, and waterway opening for the duration of the run-around. Periodic inspection of the structure must be
made and any questionable members or connections that are damaged or
over-stressed must be corrected immediately.
1. Document structure and its conformance to the plans.
2. Document date installation starts and when the
structure is removed.