Maclay Bridge Rehabilitation Jai B. Kim, PE, PhD Robert H. Kim, PE, MSCE Phone: (570) 490-7811 Email: jaikim@bucknell.edu
Maclay Bridge Components
Maclay Bridge Components
Arch Rehabilitation Concept
Maclay Bridge Background •Built 1935, rehabilitated 1964. •Pin-connected Parker truss main span = 180.1 ft and Warren pony truss span = 39 ft, Roadway 16 ft; Traffic = 1,890 (2014). •Present weight limit: 11 tons. •Listing in the National Register of Historic Places (NRHP) is pending. •Abstract: The economic situation requires that the bridge should usefully serve its purpose for as long as possible. Various methods of strengthening would help to prolong its useful life.
Maclay Bridge Conceptual Alternatives Five Possible Alternatives: 1. Rehabilitate with arches for 36 tons - Parker truss main span with pedestrian/bikeway. A. Replace the Pony and concrete spans with new single span to allow for removal of the piers. 2. Widen the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes (one lane each direction) plus 2-ft shoulders and 4’ 6” pedestrian/bikeway, and increase the live load capacity. Replace the Pony and concrete spans with new single span to allow for removal of the piers. 3. A new one-lane Parker truss bridge parallel to the rehabilitated existing Parker truss bridge. Have the rehabilitated Parker truss bridge listed in the NRHP.
Maclay Bridge Conceptual Alternatives Five Possible Alternatives (cont’d): 4.Construct a new two-lane bridge (one lane each direction) concrete or steel beam parallel to the rehabilitated existing Parker truss bridge which will be used for pedestrians/bikeway only. 5.Replace the existing Parker through truss bridge with a new similar, wider two-lane Parker through truss bridge.
Maclay Bridge Conceptual Alternatives Alternative 1: Rehabilitate with arches for 36 tons - Parker truss main span with pedestrian/bikeway. • The MDT Bridge Design Standards, SURFACE TRANSPORTATION PROGRAM (STP) Secs A) 1) and D) 3) f) Truss Rehabilitation requirements may be met . • Design for HS-20 (36 tons). • List in the NRHP after the rehabilitation as done in Maryland, New York, and Pennsylvania after the arch rehabilitation.
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway. • Rehabilitate the bridge as quickly as possible for the safety of traveling public. • Keep the cost of rehabilitation as low as possible. • Protect the surrounding environment from the impact of the construction (no impact on the river). • Rehabilitated bridge will have least amount of changes to the historic site and aesthetics.
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway. • Add structural redundancy and remove the fracture - critical characteristics of the bridge. • No need for new foundations and new piers. • Costs will be lower: estimated to be $4,000 to $7,000 per lineal ft of bridge. For 180’ main Parker truss, the costs could range from $720,000 to $1,260,000 for short construction time period, with intermittent traffic on the bridge. • Costs for approach spans would depend on option chosen (rehab existing spans with sidewalk on down stream side ~$280K or remove two piers and replace with single span Parker truss with sidewalk on one side ~$800K).
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway. • No waterway disturbance with new piers. • No need for acquiring new right-of-way properties. • During some phases of the rehabilitation, traffic will be allowed on the bridge.
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway.
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway. Pedestrian/Bike Way can be on either side of bridge (upstream or downstream)
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway.
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway. Lycoming County, Pennsylvania, 62 ft Pony Truss from 5 tons to 36 tons
Maclay Bridge Conceptual Alternatives Alternative 1 (cont’d): Rehab with arches for 36 tons - Parker truss main span with pedestrian/bikeway. Lycoming County, Pennsylvania, 62 ft Pony Truss from 5 tons to 36 tons
Maclay Bridge Conceptual Alternatives Alternative 2: Widen the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes (one lane each direction) plus 2-ft shoulders and 4’ 6” pedestrian/bikeway, and also increase the live load capacity. Replace the Pony and concrete spans with new single span to allow removal of the piers. References: Checkered House Bridge, Vermont; and the Huey P. Long Bridge, New Orleans, Louisiana.
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes… • Increased bridge live load capacity to an HS-20 (36 tons) with the least changes to the bridge in its original material and aesthetics so that the bridge may be listed in the NRHP. • The MDT Bridge Design Standards, SURFACE TRANSPORTATION PROGRAM (STP) A) 1) & D) 3) f) requirements may be met.
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes… • The rehabilitated Parker truss bridge will carry two lanes, one lane each direction. • No new foundations and piers in the water ways will be needed, since the new W frame pier caps anchored to the existing piers will support the widened bridge.
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes… • Costs will be lower: estimated to be maximum $7,000 per ft of Parker truss bridge. The Pony truss and concrete approach spans would be widened to maintain compatibility with the main Parker truss span or replaced with single span to allow removal of the piers. Cost of approach spans would depend on option chosen. • Short construction time period. • No waterway disturbance.
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes… Pedestrian/Bike Way can be on either side of bridge (upstream or downstream)
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes…
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes… Historic Preservation – Truss Separation Widens Historic Vermont Bridge The Checkered House Bridge (built 1929) moved 12 - ½ ft (September 2012, Civil Engineering )
Maclay Bridge Conceptual Alternatives Alternative 2 (cont’d): Widening the trusses to 26’ 0’’ from existing 17’ 2” for two 10-ft traffic lanes…
Maclay Bridge Conceptual Alternatives Alternative 3: A new one-lane Parker truss bridge parallel to the rehabilitated existing Parker truss bridge. Have the rehabilitated Parker truss bridge listed in the NRHP. Great River Bridge Westfield, MA
Maclay Bridge Conceptual Alternatives Alternative 3 (cont’d): A new one-lane Parker truss bridge parallel to the rehabilitated existing Parker truss bridge… • Save the existing landmark Parker truss bridge. • The rehabilitated Parker truss bridge will remain as it is with one-way traffic lane and rehabilitated for HS-20 live loading (36 tons). • The new parallel Parker truss will be for one-way traffic lane and is designed for HL-93 loading. • Costs and construction time: To be determined. • Have the rehabilitated bridge listed in the NRHP.
Maclay Bridge Conceptual Alternatives Alternative 4: Construct a new two-lane bridge (one lane each direction) concrete or steel beam parallel to the rehabilitated existing Parker truss bridge for pedestrians/bikeway only. • The new bridge will carry two lanes, one lane each direction and will be designed for HL–93 loading. • Retain the rehabilitated Parker truss bridge as-is to carry only pedestrian/ bicycle traffic. • The new bridge will need new foundations and piers.
Maclay Bridge Conceptual Alternatives Alternative 4 (cont’d): Construct a new two-lane bridge (one lane each direction) concrete or steel beam parallel to the rehabilitated... • Have the existing rehabilitated Parker truss bridge listed in the NRHP. • Estimated Cost: To be determined.
Maclay Bridge Conceptual Alternatives Alternative 4 (cont’d): Construct a new two-lane bridge (one lane each direction) concrete or steel beam parallel to the rehabilitated...
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