DAL Bridge 90 Percent SOW.pdf

Scope of Work

Contract Name: Dale Hollow Dam Bridge Repair Project

This project is performed at the Dale Hollow Dam located in Clay County TN. The scope of work is to remove and replace the deteriorated concrete that meets Condition State 3 or worse (as defined by AASHTO) from the concrete overhanging sections along the concrete bridge deck. There are 6 bridge deck spans @ 60’ clear distance (Figure 1). Each concrete overhang extends approximately 3 ft from the center line of the girder at a height of 20” (Figure 4 & Figure 5). There are two overhanging sections per span:

upstream side and downstream side.

The plan will include concrete removal to sound substrate, corroded rebar removal, reinforcing/dowel placement as needed and concrete placement. The use of dowels/anchors and reinforcement may be necessary to secure the new concrete to the existing surface.

Environmental and cultural compliance as required by the National Environmental Policy Act (NEPA), Endangered Species Act (ESA), Clean Water Act (CWA), and National Historic Preservation Act. USACE will undertake coordination with state and federal regulatory agencies for legal compliance and will take an estimated 45 – 60 days. Dale Hollow Dam is a property eligible for inclusion in the National Register of Historic Places. Care must be taken to avoid damaging character defining features such as the railings.

The repair plan will be coordinated with the State Historic Preservation Office prior to approval to ensure the Corps meets their obligations under the NHPA. The plan should be developed with consideration of affects to the human environment for NEPA compliance. Methods requiring lengthy road closures of several months may require a higher level NEPA review. Upon award USACE will schedule a kick-off meeting among the contractor and USACE Environmental and Cultural Staff to discuss compliance procedures.

Table of Figures:

FIGURE 1: ELEVATION OF ALL SPANS

FIGURE 2: CLOSE UP ELEVATION VIEW

FIGURE 3: SECTION THRU ROADWAY

FIGURE 4: CLOSE UP OF REINFORCEMENT IN BRIDGE DECK

FIGURE 5: HANDRAIL AND POST ANCHORAGE

FIGURE 6: CONCRETE SPALLING AND EXPOSED REBAR

FIGURE 7: CONCRETE SPALL

FIGURE 8: EFFLORESCENCE BUILD UP

FIGURE 9: WEARING AND MIN. CLEAR COVER

DRAFT

Figure 1: Elevation of All Spans

Figure 2: Close Up Elevation View

REFER TO FIGURE 2

REFER TO FIGURE 2

REFER TO FIGURE 3 & 4

Figure 3: Section Thru Roadway

Figure 4: Close Up of Reinforcement in Bridge Deck

Extent of damage is limited to this area for both Upstream and Downstream overhangs. Depth and height will vary.

REFER TO FIGURE 4

Figure 5: Handrail and Post Anchorage

Figure 6: Concrete Spalling and Exposed Rebar

Figure 7: Concrete Spall

Figure 8: Efflorescence

Figure 9: Previous Patch Exhibits Weathering and Min. Clear Cover DRAFT