2013 TRB WORKSHOP ADVANCING THE USE OF CULVERTS FOR HIGHWAY BRIDGES
SR 60 OVER HOGGATT BRANCH 30’ SPAN CULVERT EXTENSION
SALEM, INDIANA
JEFF VON HANDORF, PE
PRETEK GROUP LLC
JANUARY 13, 2013
PROJECT TEAM OWNER: INDIANA DEPARTMENT OF TRANSPORTATION (INDOT) ENGINEER: CROSSROAD ENGINEERS CONTRACTOR: GOHMANN ASPHALT PRECAST PRODUCER: INDEPENDENT CONCRETE PIPE, LOUISVILLE, KY PRECAST STRUCTURAL ENGINEER: PRETEK GROUP LLC STRUCTURE TYPE: ECO-SPAN™ SINGLE-RADIUS ARCH
PROJECT LAYOUT
Presenter
Presentation Notes
As part of a new bypass around the city of Salem, Indiana, it was necessary for INDOT to widen the existing State Route 60 near the intersection with the new road. Since SR 60 was the main road to nearby Louisville, Kentucky and there was no quick detour, closing the road during construction was not an option.
Presentation Outline:
• EXISTING STRUCTURE
• TSL OPTIONS
• BID PLANS
• SHOP DRAWINGS
• PRODUCTION
• INSTALLATION
• FINISHED STRUCTURE
EXISTING ARCH BRIDGE
Presenter
Presentation Notes
The existing bridge was a 30’ span x 17’ clear rise x 78’ long cast-in-place arch carrying two lanes of traffic with about 13’ of earth cover. It was built in 1948.
EXISTING ARCH BRIDGE
Presenter
Presentation Notes
This structure was in good condition in spite of the 60-plus year age. It was well sized for the stream, spanning the base flow channel with room to spare and provided about 9 feet of freeboard according to INDOT’s hydrualic analysis at the 100-year storm event.
EXISTING STRUCTURE PLANS (1947)
Presenter
Presentation Notes
Plans showed that the arch was 9” thick at the top and changed radius as it approached the foundation. Thickness also increased near the base.
EXISTING STRUCTURE PLANS (1947)
Presenter
Presentation Notes
The existing structure looks very similar to the precast structures built today.
TYPE/SIZE/LOCATION SELECTION
The culvert-sizing process is performed in accordance with a priority system. The design priority system is as follows: 1. Single Circular-Pipe Installation. 2. Single Deformed-Pipe Installation. 3. Single Specialty-Structure Installation. 4. Multiple Circular-Pipes Installation. 5. Multiple Deformed-Pipes Installation. 6. Multiple Specialty-Structures Installation. SOURCE: INDIANA DESIGN MANUAL CHAPTER 203
Presenter
Presentation Notes
Given the age of the bridge, INDOT’s first thought was to replace the structure. The consultant followed the Indiana Design Manual’s culvert-sizing process which gives strong preference to single-span openings over multiple-span openings. In this case options 1 and 2 were too small, so a specialty structure was chosen.
TYPE/SIZE/LOCATION SELECTION
1. A pipe structure is preferred to a specialty structure, e.g., precast reinforced-concrete box section, precast reinforced-concrete three-sided culvert, structural plate arch. 2. A circular pipe is preferred to a deformed pipe. 3. A single-cell installation is preferred to a multiple-cell installation. 4. Multiple-cell installation should be considered as a last resort. If a multiple-cell installation is being considered, the Office of Hydraulics should be contacted. SOURCE: INDIANA DESIGN MANUAL CHAPTER 203
Presenter
Presentation Notes
Specialty structure options include precast box culverts, precast three-sided culverts, and structural plate arches. It should be noted that if the specialty structure span exceeds 30 feet, a conventional style bridge is also considered.
TYPE/SIZE/LOCATION SELECTION
PROPOSED REPLACEMENT STRUCTURE: 198 LF 32’ SPAN X 9’ RISE THREE-SIDED PRECAST ARCH-BOX TOTAL ESTIMATED COST: $740,000 (DEMOLITION, EXCAVATION, FOUNDATIONS, INSTALLATION, BACKFILL, ROADWAY) MAINTENANCE OF TRAFFIC (MOT): $544,000 TOTAL PROJECT COST: $1.284 MILLION
Presenter
Presentation Notes
In this case, the consultant recommended a 32’ span x 9’ rise precast arch-box structure with a length of 198 feet. Estimated cost including demolition, excavation, foundations, the precast structure itself, installation, backfill, and roadway was $740,000. An additional $544,000 was estimated for maintenance of traffic for a temporary run-around since traffic needed to be maintained at all times. The total estimated cost was $1.284 million.
TYPE/SIZE/LOCATION SELECTION
ADDITIONAL ALTERNATES: MSE WALL ON EXISTING ARCH: $424,000 + $544,000 MOT = $968,000 WIDEN WITH THREE-SIDED ARCH (RECOMMENDED) $400,000 + $144,000 MOT = $544,000 (REHABILITATION COST = 544/1,284 = 42% OF RECONSTRUCTION COST) NOTE: ESTIMATED LIFE EXPECTANCY OF EXISTING ARCH = 18 YRS. +
Presenter
Presentation Notes
After further inspection of the existing 1940’s era arch, INDOT found that it had no deficiencies and estimated the remaining life of the structure to be at least 18 years. With that in mind, additional options for rehabilitation of the structure were available. The first was using MSE walls to extend the existing headwalls and wingwalls up to road grade so that the road could be widened. However, with this option, each shoulder width would have needed to be decreased by 2’. In addition, a temporary run-around would still be required since installation of MSE straps would require demolition of the existing road. Total estimated cost for this option was $968,000. The second option was to use available precast shapes which nearly matched the existing arch to extend the structure. MOT costs were reduced significantly with this option since the road could remain in service with only partial lane closures. MOT was reduced to a simple widening project, saving approximately $400,000. With the reduced MOT cost and construction costs, the total for this option was $544,000, for a 42% savings compared to replacement cost. The consultant recommended this option to INDOT.
TYPE/SIZE/LOCATION SELECTION
SOURCE: INDIANA DESIGN MANUAL FIGURE 72-2C
Presenter
Presentation Notes
The Indiana design manual includes a helpful curve for determining if rehabilitation or replacement is more cost-effective. In this case, the 42% savings combined with the 18 year extended service life landed comfortably on the “Rehabilitate” side of the curve. INDOT moved forward with the consultant’s recommendation.
BID PLANS
Presenter
Presentation Notes
Bid plans showed a 40 foot extension on the upstream side and 32 foot extension on the downstream side.
BID PLANS
Presenter
Presentation Notes
A twin-leaf arch was shown on the plans, but INDOT specifications also allowed for a one-piece design.
BID PLANS
Presenter
Presentation Notes
Basic performance requirements were provided, and final design was left up to the contractor and supplier at shop drawing stage. This approach allows the contractor flexibility to find the best solution and saves the owner some of the up-front engineering cost.
SHOP DRAWINGS
Presenter
Presentation Notes
The contractor chose the 30’ span x 11’ rise ECO-SPAN single-radius arch with a 5’-2” tall cast-in-place stem wall. This configuration was a close match with the existing structure.
SHOP DRAWINGS
ARCH UNIT PRODUCTION
Presenter
Presentation Notes
Seven arch segments and four headwall pieces were produced at Independent Concrete Pipe in Louisville, KY.
INSTALLATION – DELIVERY
Presenter
Presentation Notes
They were shipped to the site in the casting position.
INSTALLATION – DELIVERY
Presenter
Presentation Notes
At the site they were unloaded and rotated upright.
INSTALLATION
Presenter
Presentation Notes
Once upright, they were moved to the cast-in-place foundation.
INSTALLATION
INSTALLATION
Presenter
Presentation Notes
The existing headwalls and wingwalls were left in place. A small area was demolished at each corner where a cast-in-place closure pour would connect the existing arch to the new precast structure.
INSTALLATION – ARCH UNITS
Presenter
Presentation Notes
One lane of the road was closed during installation with flaggers directing traffic. Installation was one short day for each end. Otherwise, traffic continued without interruption.
INSTALLATION - HEADWALL
Presenter
Presentation Notes
Precast headwalls were installed after the arches. Steel ties kept the arches from spreading until they were backfilled.
CASTING CLOSURE POUR
Presenter
Presentation Notes
Forming the cast-in-place transition was relatively easy with the two arches in place.
FINISHED STRUCTURE
Presenter
Presentation Notes
The finished structure maintains the character of the original.
FINISHED STRUCTURE
Presenter
Presentation Notes
In addition to the maintenance of traffic advantages offered by this solution, stream disturbance was minimized by extending the structure instead of replacing it.
SUMMARY
ESTIMATED SAVINGS RESULTING FROM 1947 USE OF BURIED BRIDGE: • $740,000 – 2011 EXTENSION IN LEIU OF REPLACEMENT • ESTIMATED 2 DECK REPLACEMENTS (25-30 YEAR LIFE OF EACH)
• POSSIBLE BRIDGE REPLACEMENT PRIOR TO WIDENING
Presenter
Presentation Notes
INDOT’s decision in 1947 to use a buried bridge instead of a traditional bridge with a deck has paid huge dividends over the life of the structure. This project demonstrates how buried bridges can be a great long-term investment for transportation agencies.