Preserva on Assessment

Transcription

1 Preserva on Assessment For Upham Road Bridge over Gaylord Creek BMS # Susquehanna County PennDOT Engineering District 4 0 Final Report Dec 2017 Prepared by TranSystems for the Pennsylvania Department of Transporta on Environmental Policy and Development Sec on

2 BRIDGE LOCATION LOCATION VICINITY N BRIDGE LOCATION MAP Upham Road (T-498) over Gaylord Creek Middletown Township, PA Source: PA Type 10 Map Susquehanna County

3 RESOURCE LOCATION QUADRANGLE LOCATION SCALE SOURCE N 0ft 2000ft USGS 2013 Lawton, PA Upham Road (T-498 ) over Gaylord Creek Middletown Township, Susquehanna County, PA

4 PENNSYLVANIA METAL TRUSS BRIDGE PRESERVATION/REHABILITATION ASSESSMENT EVALUATIONS The purpose of this assessment is to provide a benchmark analysis in which to understand rehabilitation options based on existing conditions of the bridge and adjacent areas at the time of the analysis and the observed usage. This assessment is not a Historic Bridge Rehabilitation Analysis, with purpose and need established, and a more in-depth study may be required if the project is to be further developed. The ability of this analysis to determine whether the bridge can be rehabilitated to meet project need is constrained by the fact that actual need is not established for this analysis and that data utilized is based on a field view, file research, and chance interviews with local parties. When actual project need is established, this information will be updated based on current field data. A final determination of whether rehabilitation can meet the project needs and would be considered feasible and prudent under Section 4(f) of the USDOT Act of 1966 will be determined during the NEPA/Section 4(f) process. BMS #: Bridge Key #: District: 4-0 County: Susquehanna Township: Middletown Owner: County Maintenance: Susquehanna County Location Information: 0.5 mile west of PA 858 Road; 3.1 mile southwest of Middletown Bridge Name: Upham Road over Gaylord Creek Susquehanna County Bridge No. 30 Type: Pony Truss Design: Pratt (Pinned) Truss Materials: Steel Date: 1886 CA Alter/Rehab: Yes; Dates Unknown Source: Style Length: 79' Number Spans: 1 Deck Width: 15-8 Bridge Description The one span, 79' long, five-panel, pin connected Pratt pony through truss bridge is supported on stone masonry abutments. The truss tension members are rods and eyebars, and the compression members are built-up sections consisting of a pair of channels with a riveted top plate and bottom battens. The verticals are angle pairs connected by lacing. The built-up floorbeams and rolled I-beam stringers support the Upham Road Bridge Assessment Page 1

5 timber deck. Bridge deck consists of 2"x6" timbers placed on edge. The travel way width is 13' on the bridge and the approaches are 15' wide earth and gravel. NR Eligibility Status: Eligible under Criterion C for technological significance. Historic Preservation Priority: Moderate (see Protocols for Levels of Priority located at Historic Preservation Priority Justification: Inspection records document the date of construction to 1886, but the bridge plaques have since been lost and no information is readily available on the builder. This likely wrought iron bridge is an early and complete representative example of its type and design making it historically and technologically significant. The character-defining features include the truss form and method of truss member end connection (pinned Pratt Pony truss). Roadway & Site Information Setting Description: The bridge is located on a one lane unimproved road north of the T intersection with SR 858 in a rural setting with woodlands, active agriculture and scattered houses. The bridge and road have a very low reported traffic volume. Type of Bridge Service: One lane (less than 18'-wide travelway) serving twodirectional traffic. Bridge Roadway Width: 13'-0" curb-to-curb Approach Travelway Width: 15' Vertical Clearance: N/A. Functional Classification: Rural Local ADT(Date): The BMS2 lists the ADT on the bridge as 25 vpd (2016). The source of the BMS traffic count on the bridge is not known. This is an estimate and represents a conventional entry for low volume local roads in Susquehanna County. Since AASHTO guidance on bridge width is founded on the number and types of vehicles that use a bridge, starting with an accurate assessment is critical, especially when the ADT on a rural local road is less than 400 and is projected to remain under Upham Road Bridge Assessment Page 2

6 400 for 20 years. When bridges that do not meet current design criteria (functionally obsolete) are located on very low volume local roads and are performing satisfactorily (absence of documented crash history), AASHTO policy affords the opportunities to keep functionally those bridges in service. Shoulders/Sidewalks: Earth approach shoulders are heavily vegetated and low in areas. Also, vegetation is encroaching roadway throughout. Observed Crash History: None observed. Specific crash history data (from local police) was not available for this site, so observed conditions of impact were used to make a determination. Safety Features: A single piece of angle iron is welded to the truss members. The angle iron piece is flexible, rusted, and slightly loose. Hazard clearance signs are missing and need to be provided at all four corners since there is no approach guiderail. Proximity of Alternate Routes: To reach the south side of the bridge on Upham Road, there are two alternate routes available. To the east, the alternate route is 3.3 miles long, using Beaumont Road (SR 0468), SR 4017 and Bomont Road to bypass 2.3 miles on Upham Road. To the west, the alternate route is 4.7 miles long, using Prattville Road (SR 1011), and East Road SR 1026 would be traveled to bypass 3.3 miles on Upham Road. There are no height restrictions on either route. It is unknown whether there are any weight restrictions on either route. The actual alternate route length traveled would be dependent on the ultimate origin and destination of the individual traveler. Summary Geometric Deficiencies: With a bridge roadway width of 13'-0", the bridge is classified as functionally obsolete because it does not meet the 18' definition of a two lane facility. The road is also a one lane facility. The horizontal curve at south abutment and a hill at north abutment create potential sight distance problems. Speed reduction is required. The vegetation surrounding the structure and both approach roadways also create potential site distance problems. Performance Summary: While the bridge did not meet current design requirements, there is no evidence of a crash history and therefore it appears that the bridge is operating in a safe manner for those vehicles permitted to use the bridge. Hydraulics: Huntington Creek flows east to west. There is minor scour in the center of the channel under the structure. Both abutments are well protected with placed rock protection. The banks are generally stable with several areas of erosion upstream and downstream. The waterway opening is satisfactory with a slight chance of overtopping, as per BMS2. Upham Road Bridge Assessment Page 3

7 BMS Condition & Load Sufficiency Condition Code Ratings (2016) Superstructure: 3 Serious Substructure: 4 Poor Deck: 7 Satisfactory Load Ratings Inventory: 6T Operating: 11 T Method: Load factor (floorbeams & stringers) Allowable stress (truss) Posted? Yes (10 tons) LOAD FACTOR METHOD (unless noted otherwise) STRUCTURAL MEMBERS H20 HS20 ML80 TK527 (20 Tons) (36 Tons) (37.74 Tons) (45 Tons) STRINGERS (inv.) 8* 14* 15* 17* STRINGERS (opr.) 13* 23* 25* 29* (1) FLOORBEAM (inv.) 6* 12* 8* 10* (1) FLOORBEAM (opr.) 11* 19* 13* 16* (2) TRUSSES U2L3 (inv.) 11* 16* 14* 16* (2) TRUSSES U2L3 (opr.) 18* 25* 22* 25* (2) TRUSSES U4L3 (inv.) 11* 16* 14* 16* (2) TRUSSES U4L3 (opr.) 18* 25* 22* 25* (1) Controlling Members (in red) (2) Allowable Stress Method (*) indicates insufficient capacity for given truck The latest analysis is from The bridge has been posted for a weight restriction of 10 tons except combination vehicles of 18 tons since August 20, The floorbeams control the rating of the superstructure with a H20 capacity of 6 tons at inventory rating level and 11 tons at operating rating level. The controlling truss members are U2L3 and U4L3 with a posting of 11 tons at inventory stress levels. For truck loading schematics showing the axle loads, see Appendix. The inventory rating level results in a live load which can safely utilize an existing structure for an indefinite period of time. The operating rating level generally describes the maximum permissible live load to which the structure may be subjected. Allowing unlimited numbers of vehicles to use the bridge at operating level may shorten the life of the bridge. Summary Structural Deficiencies The bridge is rated in overall serious (3) condition due to the condition of the superstructure. Based on BMS2 data, confirmed by a cursory field view, the following specific deficiencies were observed. Refer to photographs for additional details. Upham Road Bridge Assessment Page 4

8 Truss Lines All truss elements are severely rusted. The lower chord is bent and overstressed at the first panel from the southwest corner. The diagonal member at the center of the upstream truss is loose at the top. There is section loss at the pins. Floorbeams The top and bottom flanges, and lower web areas of all the floorbeams exhibit moderate rust causing moderate section losses. The first beam from the south abutment is the worst with heavy built up angle pieces riveted to top and bottom of flanges. Also this beam appears to be overstressed showing signs of twisting/bending. Stringers All stringer bearing areas have moderate section loss on the flanges and minor section loss in web. Section loss has created small holes in the web of the third beam from the upstream side at the north abutment bearing area. Substructure The dry laid stone abutments exhibit displaced stones, voids, loose stones, missing or cracked stones and large gaps. There is settlement evident at the right side of south abutment and all the wings. The substructure units are not distinguished features of the bridge. Their design and material does not affect its historic significance. Deck The timber deck has moderate to heavy mud accumulation on the deck. Some splintering is present and there is some unevenness to the timber members throughout with some areas warped at the ends. The underside exhibits some moisture retention. Paint Condition Pitting, peeling, and flaking paint is present throughout at the stringers and floorbeams. The truss members exhibit areas of light to moderate rust. The bearings are heavily rusted. Rehabilitation & Preservation Considerations Benchmark for Assessing Rehabilitation The existing bridge has a moderate historic preservation priority and is located on a very low volume local road with an extremely low reported volume of traffic. There are nearby alternate routes as detailed on Page 3 that provide access to the adjacent areas of the bridge. It needs to be determined if a bridge is necessary at this crossing and if making the needed structural repairs to make it satisfactory could be undertaken. The bridge has structural deficiencies related to deterioration of the trusses, floorbeams, stringers, coating system and abutments. There are conventional treatments to correct the deficiencies. Upham Road Bridge Assessment Page 5

9 Specific Options to Address Existing Conditions and AASHTO Criteria The options considered strive to address the well-supported structural deficiencies associated with the physical condition of the bridge, like failing paint and related corrosion of the steel, and the low load carrying capacity as a result of deteriorated components of the floor system. Traditional treatments for improving load carrying capacity based on the capacity of the trusses are considered. This analysis is based on considering options that make the bridge structurally satisfactory while preserving what makes it historic. Options for addressing the deficiencies are divided into four categories (1) maintenance; (2) rehabilitation without adverse effect; (3) the option of building on a new location without using the old bridge and (4) other reasonable options. Maintenance The bridge has deteriorated beyond the point where the structural deficiencies can be addressed by routine maintenance. However, if the bridge were to be repaired and repainted, there are conventional and cost effective treatments that should be performed on a routine basis in order to significantly reduce life cycle costs, like cleaning the bridge to maximize the life of the coating system. Rehabilitation without Adverse Effect Section 106 of the National Historic Preservation Act of 1966 (NHPA) requires federal agencies to take into account the effects of their proposed improvement on historic properties. An adverse effect on an historic resource occurs when the proposed improvement alters the character defining features that qualify the property for inclusion in the National Register. Adverse effects can be avoided by rehabilitating the structure to the Secretary of Interior s Standards for Rehabilitation. This could be accomplished by implementing the following rehabilitation program. Rehabilitation of the bridge would include conventional treatments that would not alter the characteristics that make the bridge historically significant. Structural deficiencies could be addressed by replacing deteriorated sections or the entire members of the truss and floor system with an in-kind repair or total replacement. A No Adverse Effect is likely as long as the existing end connection details are utilized (pinned truss members and the floorbeam connection detail). Truss strengthening to achieve a higher load capacity can also be achieved without adverse effects by in-kind replacement with a higher strength material or providing a secondary support system (i.e. post-tensioning or adding supplemental members). Truss expansion bearings could be replaced with neoprene or polytetrafluoroethylene (PTFE, better known as Teflon ) bearings while the fixed bearings could be cleaned and repainted. Repair to the substructure units or replacement of the existing substructure unit with concrete abutments would not adversely affect the historic significance and cultural value of the bridge, as it is not considered a character defining feature of the bridge. The appropriate placement of safety features to protect motorists and the truss lines is also permissible. The original bridge railings should be retained and the new railings should not be attached to the Upham Road Bridge Assessment Page 6

10 truss. It may be efficient to lift the truss from its seats in order to repair or reconstruct the abutment(s) in order to allow easier access to the work and avoid costly stream regulations and restrictions. The cost of structural repairs to the trusses and cleaning and painting should be estimated with the bridge on the ground rather than over the stream. The following budgetary cost estimate has been developed (utilizing unit costs generated from previous truss rehabilitation projects and modified to reflect specific site constrains/conditions) to provide a rehabilitated structure that makes the bridge satisfactory for this site and meets a 15 ton minimum capacity. This value is the generally accepted minimum load carrying capacity for rehabilitated structures and represents the anticipated weights for a school bus, oil deliver truck, and small emergency service vehicle. Based on a review of the available structural analysis, it appears that a rehabilitation that results in a 20 ton weight limit would be possible without adverse effect; however, 4 additional truss members would require strengthening. If additional carrying capacity is determined to be required when a purpose and need is developed for the project, additional analysis would be needed. This would be addressed by means of additional analysis during the NEPA process. Cost Model - Rehabilitation Program for 15 Ton Capacity Remove Portion of Existing Bridge L.S. $8,000 Temporarily Remove & Reset Truss L.S. $35,000 Construct New Substructure Units 90 $1,500 $135,000 Truss Repairs $7,500 $52,500 Truss Bearings $5,000 $20,000 Floorbeam Repairs $5,000 $15,000 Clean & Paint Superstructure L.S. $100,000 New Stringers 5 x 80 x 30# = 12,000 LB x $3.50 $42,000 New Timber Deck 1,280 SF x $20 $25,600 Bridge Railing 160 x $100 $16,000 Approach Guiderail 300 x $50 $15,000 Subtotal: $464,100 20% $92,820 TOTAL: $556,920 Considering a 25 year life-cycle analysis that includes a 3% inflation rate and yearly flushing of the truss and bridge seats and spot cleaning and painting, the following costs should be added to this estimate. The cost does not include engineering, mobilization, maintenance and protection of traffic, erosion control measures, etc. Upham Road Bridge Assessment Page 7

11 Flushing Truss/Bearing Area $1,000/YR 25 ($ ave.) $42,837 Timber Deck Repairs 10 & 20 years $7,875 $3,360 + $4,515 Spot Cleaning & Painting 15 years $15,580 TOTAL: $66,292 The cost model yields a total rehabilitation program in present dollars equal to $625,000. The cost for a bridge replacement is estimated to be approximately to $1,100,000 based on similar statewide projects. The cost does not include engineering, mobilization, maintenance and protection of traffic, erosion control measures, etc. Other Reasonable Options For Reuse This is a very low volume local crossing, and there are adequate alternate routes to access properties on either side of the bridge. Although meeting any likely need, the cost for building a new bridge on a new alignment in close proximity to the existing structure, while leaving this historic bridge in place, is essentially the same as replacement. Ownership and maintenance of the existing bridge is left undetermined, which might not be conducive to long-term preservation. If it is determined that the actual need does not require a crossing at this location, then removal, relocation, and rehabilitation of the existing structure to the Secretary of Interior s Standards for Rehabilitation is an option that could also result in a No Adverse Effect. Likewise, if construction of a new bridge is required based on the project needs, then the removal, relocation, and rehabilitation of the existing structure to the Secretary of Interior s Standards for Rehabilitation is also an option that could result in a No Adverse Effect. That work would still require that the truss deficiencies be addressed and the bridge cleaned and painted. Because the bridge is accessible and the span length is relatively short, it is possible to lift the bridge and transport it. Summary of Rehabilitation Options Ultimately, the investment into a rehabilitation of a historic bridge works best when there is a long-term potential for preservation. Because of that goal, there is a hierarchy of rehabilitation options. Highest is the rehabilitation of the existing bridge at the current location that continues to meet transportation need at that crossing. Below that is a relocation and rehabilitation of the bridge to another crossing or rehabilitation of the bridge on existing location for a use other than the transportation need. The least preferred option is dismantling and storage of the historic bridge for a future use. This provides no assurance that the bridge will ever be rehabilitated and re-used, and would result in a finding of adverse effect. Based on the observed conditions and usage prior to closure, the Upham Road Bridge could be rehabilitated to carry 15 tons without altering its character defining features and could still be eligible for the National Register. The cost of the rehabilitation would be less than the cost of a new bridge. There are definite challenges to moving forward with rehabilitation due to the work that must be done to address deterioration of the Upham Road Bridge Assessment Page 8

12 truss members, but rehabilitation appears to be a cost effective option. With conventional treatments for repairing or replacing these elements on the trusses and cleaning and painting the trusses with a properly done coating system, it is likely that the bridge would last a minimum of 25 years with routine maintenance. If construction of a new bridge is required at the crossing based on project needs or if the actual need does not require a crossing at this location, then removal, relocation, and rehabilitation of the bridge would likely result in a No Adverse Effect finding and provide utility of the structure in another use. That use could be in a transportation purpose or in a non-vehicular use. Upham Road Bridge Assessment Page 9

13 UPHAM ROAD 4 3 FLOW GAYLORD CREEK LEGEND X PHOTO NUMBER AND DIRECTION TITLE NTS UPHAM ROAD

14 Photo 1: Deck Looking North Photo 2: South Approach Looking South Upham Road Bridge Assessment Photo Page 1

15 Photo 3: North Approach Looking North Photo 4: North Approach Looking South Upham Road Bridge Assessment Photo Page 2

16 Photo 5: East Truss Line Photo 6: Southeast Truss Bearing Covered with Dirt and Vegetation Upham Road Bridge Assessment Photo Page 3

17 Photo 7: Typical Truss to Floorbeam Connection. Note Kinked Diagonal Photo 8: Top Chord Splice Detail Upham Road Bridge Assessment Photo Page 4

18 Photo 9: Angle Serving as Bridge Railing Welded to Truss Member Photo 10: Underside View of Truss Upper Chord Upham Road Bridge Assessment Photo Page 5

19 Photo 11: Kinked Corner on East Truss Photo 12: Mud Covering North Half of Timber Deck Upham Road Bridge Assessment Photo Page 6

20 Photo 13: Overall view of Deck Underside and Superstructure (NBIS report) Photo 14: South Abutment. Note the Abutment is Well Protected with Placed Rock (NBIS report) Upham Road Bridge Assessment Photo Page 7

21 Appendix Truck Loading Information

22 The figures below show common truck axle loadings used for analysis of bridges in the state of Pennsylvania. Note the following: One KIP = 1,000 pounds 2,000 pounds = 1 Ton One wheel load = Axle load divided by two The following sheets show the approximate weights of common vehicles.

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