Microsoft Word - Draft Report_Dec2014.docxAdams Street Bridge Bridge No. 00004 KAS Project#: 806140128 Artisan Project#: 14240 Prepared for: Town of Fair Haven 3 North Park Place Fair Haven, VT 05743-1066
DRAFT ENGINEERING STUDY
January 19, 2015 Prepared By:
Adams Street Bridge Town of Fair Haven, VT Engineering Study i January, 2015
Table of Contents
1.0  INTRODUCTION/BACKGROUND ............................................................................................. 1 
2.0  EXISTING CONDITIONS ........................................................................................................... 1 
2.1 VTrans 2012 Inspection Summary ...................................................................................................... 2  2.2 Project Team 2014 Investigation Summary ....................................................................................... 3  2.3 Traffic Data and Design Speed .......................................................................................................... 4  2.4 Bridge Approches .............................................................................................................................. 4  2.5 Clear Zone .......................................................................................................................................... 5  2.6 Crash Data, Nearby Intersection, and Emergency Response ............................................................ 5  2.7 Right of Way ....................................................................................................................................... 6  2.8 Utilities ................................................................................................................................................. 7  2.9 Hydraulic Analysis ............................................................................................................................... 7  2.10 Natural Resources ............................................................................................................................. 7  2.11 Cultural Resources ............................................................................................................................ 8  2.12 Geotechnical Conditions ................................................................................................................... 8 
3.0  ALTENATIVES ANALYSIS ......................................................................................................... 8 
3.1 Alternative 1: Do Nothing and Permanently Close the Bridge .......................................................... 9  3.2 Alternative 2: Rehabilitate the Existing Structure as a Vehicle Bridge ............................................... 9  3.3 Alternative 3: Rehabilitate the Existing Structure as a Pedestrian Bridge ....................................... 12  3.4 Alternative 4: Remove and Replace the Existing Bridge with a New Structure ............................... 13  3.5 Alternative 5: Removal of Existing Bridge and Construction of Utility/Pedestrian Bridge .............. 14 
4.0  PERMITTING ........................................................................................................................... 15 
5.0  RECOMMENDATIONS ........................................................................................................... 16 
Appendices Appendix A Site Plan Figures Appendix B Memo and Bridge Figures from Artisan Engineering Appendix C Project Photo Documentation Appendix D VTrans Inspection Reports Appendix E Hydrologic and Hydraulic Analysis Backup Data Appendix F Geotechnical Analysis Backup Information Appendix G VT ANR Environmental Interest Map Appendix H Alternatives Presentation Meeting Minutes
Adams Street Bridge Town of Fair Haven, VT Engineering Study 1 January, 2015
1.0 INTRODUCTION/BACKGROUND This report has been prepared for the Town of Fair Haven, Vermont (Town) and provides documentation for the development of this engineering study for the Adams Street Bridge. The project area for this engineering study includes the approaches to the bridge, the bridge, and nearby intersections. This study evaluates the project site’s existing conditions and proposed conceptual alternatives for correcting deficiencies associated with the bridge.
The Project Team for this project included experienced engineers and bridge contractors from KAS Inc, Artisan Engineering, and S.D. Ireland. Mr. Stephen Diglio, P.E., of KAS was designated as project manager and is a Vermont Licensed civil engineer with over 10 years of design experience. Mr. John Higgins, P.E. and Josh Golek of Artisan Engineering provided structural engineering services including a limited investigation of the existing bridge conditions, and structural design of proposed replacement alternatives. Mr. Ron Bushnell of S.D. Ireland, project manager for bridge construction projects, provided budgetary estimates for the various alternatives considered.
The Adams Street Bridge is located approximately 75-feet north of Vermont Route 4A, where Adams Street crosses over the Castleton River (refer to Site Location Map in Appendix A). The one lane bridge is a historic plate riveted through girder bridge with a concrete deck. The bridge is supported on concrete abutments, has a single span length of approximately 50 feet, and a curb to curb width of 12 feet. The Adams Street Bridge was closed in March 2014 by the Town due to safety concerns posed by the severe deterioration of the concrete bridge deck, including full depth holes. Elements of this engineering study include an evaluation of the existing conditions, an alternatives investigation, budgetary cost estimates, permitting, and a proposed recommendation.
2.0 EXISTING CONDITIONS Per State of Vermont Department of Highway plans dated 1960 (refer to Appendix B), the current Adams Street Bridge is a salvaged structure. It is believed that the bridge was originally built in 1919 as one of two single lane bridges that conveyed local River Street traffic over the Castleton River. When the River Street Bridges were replaced, the “better” half was moved to its current location in 1961, and reconstructed as the Adams Street Bridge. Based on interviews with Town personnel (past and present), this appears to be the last record of any significant maintenance work being conducted on the bridge.
At the time of the 1961 bridge placement, older concrete abutments were already on site. The existing abutments were rehabilitated and updated as part of the “new” bridge placement. On the Route 4A side a cast-in-place bridge seat was doweled into the older structure. On the Adams Street side a new stem and seat was
Figure 1: Project Site Area
Figure 2: Adams Street Bridge looking north
Adams Street Bridge Town of Fair Haven, VT Engineering Study 2 January, 2015
poured. Original wingwalls on both abutments were resurfaced and extended where required to retain grade. Both sets of abutments are founded on ledge and the pre-1960’s abutments appear to have at least some stone rubble backfill.
There are several stacked slate retaining walls near the bridge in varying states of disrepair. In some cases these walls are held in place by steel rod anchors doweled into ledge. The 1960 plans show a penstock for the nearby dam on the Route 4A side of the crossing. Most of the penstock slate was removed in 1961. Retaining walls closest to the abutments appear to have been reworked; walls further up and downstream seem to have been in place longer and are typically kept from collapse by steel rods doweled into ledge.
The bridge was last inspected by the Vermont Agency of Transportation (VTrans) in April, 2012. As part of the development of this study, representatives from project team visited the Adams Street Bridge in June, 2014 to take field measurements and conduct a limited investigation of the existing conditions and structural systems. The findings of these inspections are summarized in the sections 2.1 and 2.2.
2.1 VTrans 2012 Inspection Summary
Prior to its closure, the Adams Street Bridge was inspected every two years by VTrans. The bridge was last inspected by VTrans in April, 2012 and received a design load rating of H-15, which corresponds to a 30,000 lb box truck. Please reference Appendix C for a copy of the VTrans inspection report. As part of the inspection, VTrans provides the Federal Highway Administration (FHWA) with inspection findings. FHWA utilizes the inspection findings to determine a Federal Sufficiency Rating (FSR) for the bridge. The FSR is derived from a formula that considers aspects such as the condition of bridge components, average daily traffic, and the alignment of the approach roadway. Please note that the FSR is not an indication of the bridge’s ability to adequately carry traffic loads. The result of the FSR is a percentage where 100 percent is indicative of a completely sufficient bridge, and 0 percent would be considered a completely insufficient bridge. Structures that receive a FSR of 50 percent or less are eligible for federal replacement funds, and structures with a FSR of 80 percent or less are eligible for federal rehabilitation funds. The 2012 inspection results determined a FSR of 74.2 percent, which means the bridge was eligible for rehabilitation funds.
The bridge safety inspection information is also utilized to determine if a bridge is considered to be “structurally deficient” or “functionally obsolete”. A bridge is considered “structurally deficient” if the primary load bearing components are found to be in poor condition due to damage and/or deterioration. A bridge is considered to be “functionally obsolete” if the bridge geometry such as lane width, shoulder width, and guard rails do not meet current criteria. A bridge given these classifications does not necessarily imply an inherently unsafe structure. However, in some cases, load limits or vehicle restrictions may be imposed while the bridge remains in service.
The 2012 inspection determined that the Bridge was “functionally obsolete”. The bridge is considered to be “functionally obsolete” because the bridge railings, transitions, approach guardrails, approach guardrail end, and deck geometry all do not meet current standards. The bridge deck had a rating of intolerable with replacement needed. The VTrans evaluation for this bridge provided a superstructure rating of satisfactory (6) and a substructure rating of satisfactory (6). In addition, there was no
Figure 3: H-15 Design Vehicle
Adams Street Bridge Town of Fair Haven, VT Engineering Study 3 January, 2015
recommendation to post or close the bridge. Consequently, the bridge was not deemed to be structurally deficient during the 2012 inspection.
The inspection summary and needs section recommended that the concrete deck be rehabilitated with a reinforced concrete overlay, the steel superstructure needed extensive cleaning and painting to slow corrosion which was progressing, and to reface the southern abutment due to heavy scaling and sectional loss. In addition, the laid up marble retaining walls (stacked slate) were called out as being unstable and likely to collapse in a few years; though their eventual failure was determined to have no impact on the bridge itself. The inspection also mentioned that the locals had expressed concern regarding the steep drop offs at the upstream side of the bridge where there is no type of pedestrian barrier.
The bridge has continued to deteriorate since the VTrans inspection in 2012 leading to the failure of the bridge deck. VTrans inspectors were dispatched to the bridge in the spring of 2014, but an inspection was not conducted since the bridge has been closed to traffic. It is the project team’s opinion that the recent failure of the concrete bridge deck would have resulted in a structurally deficient determination had VTrans conducted the 2014 inspection.
2.2 Project Team 2014 Investigation Summary
Representatives of the project team (Mr. Stephen Diglio and Mr. John Higgins) visited the Adams Street Bridge in June 2014 to take field measurements and conduct a limited investigation of the existing conditions and structural systems. The investigation found that the existing bridge is suffering from long term deferred maintenance and deterioration consistent with a structure of this type and age. Annotated photos taken during the investigation are provided in Appendix C, and help to illustrate the findings of the investigation. The findings and major areas of concern noted are as follows:
• Severe deteriorating of the concrete deck including a number of large holes. In several locations, reinforcing steel is exposed (see photo 1);
• Significant section loss at girder ends. There is also notable section loss and rusting of the girder web at deck level, with comparable loss on the bottom flanges (see photos 2 and 3);
• Severe deterioration of the rivet heads also called “pinning”. Pining is most common at girder ends and where vertical stiffeners allow debris to accumulate on the bottom flange of the main girders (see photo 4);
• Severe cracking of the curtain walls at the beam ends (see photo 5);
• Bridge bearings were buried in concrete during the 1961 bridge replacement and could not be observed. However, it is likely that they have seized and need replacement based on prior experience with similar structures;
• Heavy spauling of concrete off the original (pre-1960’s) abutments is noticeable on both sides of the crossing. Large amounts of concrete efflorescence on the pre -1960’s abutments and some on the newer abutments was also noted (see photo 6);
• Map cracking on the 1961 abutment faces and vertical stress cracks under the bridge bearings on the Route 4A side (see photo7);
• General loss of the bridge’s protective paint;
• Slate retaining walls nearest the abutments are near collapse (see photo 8); and
• A cursory review of the existing pipe hangers supporting the water and sewer mains indicated that they are in good condition. Pipe hangers should be examined carefully during a full inspection to determine their adequacy.
Please note that the project team did not conduct a full inspection or structural analysis of the existing bridge. However, based on the limited investigation and experience with similar projects, the project team was able to draw a number of conclusions and recommendations for various bridge elements that are deficient, which are provided in Section 3.0.
Adams Street Bridge Town of Fair Haven, VT Engineering Study 4 January, 2015
2.3 Traffic Data and Design Speed
Per the 2012 annual inspection report, the Average Daily Traffic (ADT) estimate in 2008 was approximately 640 vehicles per day with approximately 2 percent as truck traffic. Since the bridge is closed, an updated traffic count is not possible. Consequently, the ADT data from 2008 is considered to be the best and only traffic data available for the bridge and was utilized for the development of this study. However, per interviews with Town residents and personnel, the consensus opinion was that the Adams Street Bridge was mainly utilized by local residents as a convenient shortcut to the post office and to cut around the village square, and that most through traffic on Route 4A would continue to the intersection with Route 22A.
The village speed limit in Fair Haven is 30 miles per hour (MPH) unless otherwise posted. Since Adams Street does not have a posted speed limit, 30 MPH was utilized as the design speed for evaluating the project area.
2.4 Bridge Approches
The southern end of Adams Street terminates at a “T” intersection with Route 4A. The bridge is located approximately 70-feet north of this intersection. The southern road approach tapers from two lanes at the intersection to one lane at the bridge over the 70-feet length. A metal guardrail is located on the west side of the road from the bridge to the intersection, and a small section of guardrail is located near the bridge on the east side of the road. The southern approach has an estimated sight distance of 200-feet, which is adequate for stopping sight distance on a low traffic road at 30 MPH. There is minimal room for north bound vehicles to stack to allow for south bound vehicles to cross the bridge. It is estimated that at most two vehicles could stack on the southern bridge approach before backing up traffic onto Route 4A. However, given the low traffic use, this appears to have been adequate.
The road approach from the north contains a sharp curve just prior to the bridge. The curve radius is estimated at approximately 80-feet, which is less than the recommended minimum design radius for a 30 MPH road. Guardrails extend approximately 40-feet from the bridge on both the east and west side of the road. The northern approach has an estimated sight distance of approximately 220-feet to the intersection with Route 4A. The northern approach has better capacity for vehicles to stack to allow for north bound vehicles to cross the bridge.
When considering the low vehicle traffic and physical constraints along Adams Street, the bridge approaches, while not ideal, are considered to meet minimal tolerable criteria. However, if the bridge is to be reopened to vehicle traffic in the future, it is recommended that the Town consider the following improvements to bridge approaches:
Figure 4: Southern Approach (from Google Maps)
Figure 5: North Approach (from Google Maps)
Adams Street Bridge Town of Fair Haven, VT Engineering Study 5 January, 2015
• Providing one lane bridge signage in accordance with Section 2c.17 of the Manual on Uniform Traffic Control Devices (MUTCD),
• Providing signage that makes south bound traffic yield to north bound traffic, and
• Providing new and extended guardrails that meet current standards.
In addition, it may be possible to extend road shoulders to allow vehicles to more easily pass each other after crossing the bridge. There are steep drop offs along both bridge approaches and no pedestrian barriers. It is recommend that pedestrian rails be added along the approaches on the upstream side of the bridge, on the bridge wingwalls, and along the existing bridge to prevent falls.
2.5 Clear Zone
The clear zone is a horizontal offset distance from the edge of the travel lane to a hazard such as a tree, utility pole, structure, steep slope, etc. VTrans design standards recommend a clear zone of 5 to 7-feet for the project area. Possible clear zone deficiencies within the vicinity of the bridge may include steep slopes, utility pole guy wire, and a hydrant.
2.6 Crash Data, Nearby Intersection, and Emergency Response
The Fair Haven police department was contacted regarding crash data for the Adams Street Bridge. Per discussions with Town police personnel, the Adams Street Bridge was not considered to be a crash prone area. In addition, there was no recollection of police responding to an accident related to the bridge.
Now that the Adams Street Bridge is closed, former bridge traffic is likely to utilize the intersection of Route 4A and Route 22A, which are both roads under the jurisdiction of VTrans. The road intersection essentially forms a “Y” shape, and also has commercial driveway access located on the east side of Route 22A. When approaching the intersection from the south (on Route 22A), traffic descends a hill, which steepens on approach to the intersection after crossing over a railroad grade. North of the intersection on Route 22A, the road is relatively flat while crossing over the Castleton River, and then begins to climb uphill towards the village. Refer to Figure 6 below for an aerial view of the intersection.
Figure 6: Intersection of Vermont Routes 4A and 22A (obtained from Google Maps)
Adams Street Bridge Town of Fair Haven, VT Engineering Study 6 January, 2015
A railroad crossing of Route 22A is located approximately 230 feet south of the intersection. The change in grade between the hill and railroad crossing reduces sight distance to approximately 230 feet to the south for traffic attempting to turn left onto Route 22A from Route 4A. Per VTrans Design Standards, the minimum recommended corner sight distance is 330 feet for a 30 MPH design speed. However, for most drivers, the change in grade caused by the railroad crossing also serves as a traffic calming measure, as most northbound vehicles on Route 22A must slow down or risk bottoming out. Based on interviews with Town personnel, a stop sign used to be located on Route 22A near the railroad tracks for northbound traffic, which appeared to be effective in further calming traffic per the opinion of the people interviewed. This stop sign was removed by VTrans to make the intersection approach more consistent with their overall policies for traffic. The sight distance is adequate when looking north on Route 22A from the intersection. The horizontal alignment of the intersection is less than ideal. Route 4A enters the intersection at a somewhat skewed angle, but it is preferred to have roads approach an intersection at a perpendicular angle (squared off).
Figure 7: View of Intersection looking south Figure 8: Looking North from Intersection
A review of the 2012 State Crash Database indicates that there were no accidents reported at this intersection in 2012. Per discussions with Town police personnel, this intersection is not considered to be accident prone, but police personnel do recall having responded to accidents at this location in the past. As previously stated, most through traffic on Route 4A would continue to the intersection with Route 22A regardless of the status of the Adams Street Bridge. It should be noted that alternate routes are available to avoid turning at this intersection, if so desired by local residents or thru traffic travelers.
When considering the intersection, the overall traffic situation appears to be tolerable and should not be a factor when considering bridge alternatives. However, it is recommended that the Town contact Trans to review this intersection and consider additional traffic clamming or traffic control measures. Given that the Route 22A bridge over the Castleton River is approximately 600-feet from the Adams Street Bridge, emergency response time is not significantly impacted by the status of the Adams Street Bridge.
2.7 Right of Way
The right-of-way is assumed to be 3-rods (49.5-feet) through the project area based on information provided by Town personnel. Consequently, the alternatives analyzed in this study would not result in right-of-way acquisitions or permanent easements. However, temporary easements may be required for staging, the removal of the existing structure, rehabilitation of stacked slate walls, and construction of the roadway slopes though the project area.
Adams Street Bridge Town of Fair Haven, VT Engineering Study 7 January, 2015
2.8 Utilities
There is a water main pipe and a sewer collector pipe supported on steel hangers that are fixed to the girder on the east side of the bridge. The water main is located near the top of the girder and is supported above triangular steel brackets that are fixed to the girder. The sewer collector is hung below the bridge and is supported by steel hangers that are also fixed to the girder. The water and sewer line return underground north and south of the bridge. A perched stormwater outfall was observed on the upstream side of the southern abutment. Evidence of additional underground utilities was not observed. Overhead utilities were observed along the east side of Adams Street.
2.9 Hydraulic Analysis
In total, the Castleton River Basin covers approximately ninety-nine square miles including all of the town of Castleton and portions of the towns of Fair Haven, Hubbardton, Pittsford, Proctor, West Rutland, Ira, and Poultney. It includes Lake Bomoseen, Glen Lake, Pine Pond, and several other smaller ponds. The contributing river basin area at the Adams Street Bridge crossing is estimated to be approximately 98.3 square miles. Per the FEMA Flood Insurance Study (FIS) for Rutland County dated August 28, 2008, the hydraulic modeling results show that the current hydraulic opening has adequate hydraulic capacity to convey the 10, 50, 100, and 500 year recurrence interval flood events below the bottom of the bridge. Since the design recurrence interval for this bridge is the 25-year event, the current hydraulic opening is more than adequate. If needed, there is room to lower the bottom of the bridge should a replacement require deeper support beams. It should be noted that the sewer collector hanging below the bridge may be susceptible to damage from a flood event. However, the sewer collector was not impacted by the flooding from Tropical Storm Irene. FEMA FIS map and profile results are included in Appendix D.
2.10 Natural Resources
The Agency of Natural Resource (ANR) Natural Resources Atlas Map was utilized to preliminary vet environmental resources (refer to Appendix D). A summary of key findings are listed below:
Wetlands: There are no mapped wetland features in the project area.
Rare, Threatened and Endangered Species: There are no mapped rare, threatened or endangered species.
Wildlife Habitats: The project area is located in an area mapped as Indiana Bat Habitat, which would restrict the allowable time period of potential tree removal from November 1st to April 30th. The Castleton River provides aquatic habit for native fish, plants and aquatic organics. Water quality measures typical for bridge work in Vermont will be required. There are also no mapped deer wintering areas in the vicinity of the project.
Surface Waters: The Castleton River runs through the project site.
Floodplain/Floodway: The portions of the project area are located within a mapped FEMA flood plain, and a mapped FEMA Floodway.
Figure 7: Water and Sewer Utilities
Adams Street Bridge Town of Fair Haven, VT Engineering Study 8 January, 2015
2.11 Cultural Resources
Historic, Architectural and Archeological
Per the VTrans Historic Preservation Program, the Adams Street Bridge is considered to be historic, as it was initially constructed in 1919. More specifically, the riveted through plate girder superstructure is considered historic. In addition, there are multiple nearby historic properties and features including, but not limited to, former mill buildings, former mill remnants and foundations, stacked slate retaining walls, and a former mill dam. Consequently, if federal funds are utilized for a proposed bridge replacement or rehabilitation project, a Section 4 (f) resource impact review will be required. Section 4 (f) stipulates that the Federal Highway Administration (FHWA) and other DOT agencies cannot approve the use of land from publicly owned parks, recreational areas, wildlife and waterfowl refuges, or public and private historical sites unless the following conditions apply:
• There is no feasible and prudent alternative to the use of land; and
• The action includes all possible planning to minimize harm to the property resulting from use.
Please note that Section 4 (f) is only applicable if federal funding is utilized. The Town can privately fund a bridge replacement project within triggering a Section 4 (f) impact review.
Agricultural Lands
The project area is completely within the Village of Fair Haven and includes previously disturbed areas. Regardless of the suitability of soils for agricultural purposes, a viable agricultural operation is not possible within the project area and it is not considered likely that there would be impacts to agricultural lands as a result of bridge improvements within the project area.
2.12 Geotechnical Conditions
Based on a review of the 1960 design plans for the bridge and site observations, ledge is shallow in the project area and the existing bridge abutments are founded on slate bedrock (ledge). The shallow ledge appears sound and is assumed to have a very high bearing capacity. Please note that geotechnical boring or test pit investigations were not conducted.
3.0 ALTENATIVES ANALYSIS Based on field investigations and coordination with Town officials, VTrans Historic Preservation personnel, and project team members (including civil engineers, structural engineers and bridge contractors), several possible alternatives for the Adams Street Bridge were developed for evaluation as follows.
• Alternative 1: Do nothing and permanently close the bridge
• Alternative 2: Rehabilitate the existing structure as a vehicle bridge
• Alternative 3: Rehabilitate and convert the bridge into a pedestrian bridge
• Alternative 4: Remove and replace the bridge with a new structure meeting current design codes and safety requirements.
• Alternative 5: Remove and replace the bridge with a pedestrian/utility bridge.
Adams Street is a Town maintained road with an estimated ADT of 640 vehicles per day with approximately 2 percent as truck traffic. It is anticipated that the proposed alternatives would be constructed with the use of State and Federal funding sources, meaning design are subject to adhere to VTrans design criteria as follows:
• Structural Capacity: H-20 (Rehabilitation), HS-25 Loading (new bridge)
• Bridge Span: 50-feet (current span), Bridge Width 12-feet (current width)
Adams Street Bridge Town of Fair Haven, VT Engineering Study 9 January, 2015
• Bridge Minimum Cross Slope: 2%
• Design Speed: 25 to 30 MPH (horizontal alignment constraints)
• AASHTO LRFD Bridge Design Specifications, 5th Edition
• VTrans Structures Design Manual, 5th Edition
Advantages and disadvantages of each alternative are discussed in the subsequent sections. Approximate budgetary costs have also been provided for each alternative. Please note that engineering costs were estimate at 15% of the construction cost, and inspection costs were estimated at 10% of the construction costs, which are typical planning costs for potentially federally funded projects. Conceptual cross sectional drawings have been developed for some of the alternatives investigated and are provided in Appendix E.
3.1 Alternative 1: Do Nothing and Permanently Close the Bridge
This alternative for the project area would be a “Do Nothing” alternative, which is to maintain existing conditions. Any evaluation of transportation improvements should include a “Do Nothing” alternative as a comparison of the costs and benefits of not implementing any improvements. The bridge only services a small number of homes on Adams Street and is readily detoured by using nearby Marble Street, Route 22A, and Route 4A. Per interviews with Town residents and personnel, the consensus opinion was that the Adams Street Bridge was mainly utilized by local residents as a convenient shortcut to the post office and to avoid the village square, but that most through traffic on Route 4A continues to the intersection with Route 22A and avoids Adams Street. In addition, emergency response time will not be significantly impacted by the bridge closure, assuming the bridge on Route 22A remains open. Consequently, the closure of the bridge has negligible traffic impacts. Access to, and support for, the two utility mains hanging off the bridge needs to be maintained even if the bridge is closed. Presumably, this requires some investment even if the crossing is closed to regular traffic and pedestrians.
Advantages:
• Low cost, and
• Cultural resource of historic bridge will remain until continued deterioration results in complete bridge failure.
Disadvantages:
• Loss of a convenient detour around Route 22A,
• Presumed minor increase in traffic on Marble Street, Route 22A, and Route 4A,
• Still requires work to provide access to utility mains,
• Town has continued liabilities associated with a failing structure and potential pedestrian falls, and
• Does not address concerns regarding lack of pedestrian barriers for steep drop-offs near the bridge.
3.2 Alternative 2: Rehabilitate the Existing Structure as a Vehicle Bridge
The project team did not conduct a full inspection or structural analysis of the existing bridge. Consequently, if the Town chooses to move forward with a bridge rehabilitation alternative, additional engineering, structural analysis, planning, and inspection will be required. The anticipated additional scope of work includes the following:
• Complete removal of the concrete deck and curbs to completely expose all steel superstructure elements. Based on prior project experience, steel superstructure elements
Adams Street Bridge Town of Fair Haven, VT Engineering Study 10 January, 2015
that have been encased in failing concrete are likely places for severe deterioration, due to the trapping of moisture and chloride (salt) against the metal.
• After the removal of the concrete, installation of scaffolding followed by a full bridge inspection conducted by a qualified inspector or engineer. Special attention paid to deteriorated steel, any remaining concrete, and inspection of the connections.
• An inspection of the abutments and bridge seats to determine repair extents. The project team expects the Adams Street side will require limited chipping and resurfacing with gunite. The Route 4A abutment is expected to need complete resurfacing and a new bridge seat.
• If the original documentation from 1919 construction cannot be found, the project team recommends testing of the structure to determine the steel’s age and design properties.
• A complete structural analysis of the bridge by a qualified structural engineer. After analysis, a judgment can be made if the H20 rating is cost effective or if a lower rating should be pursued. Since the connections are non-standard, quantifying connection capacity and detailing repairs will take significant design effort.
• If requested, review of special vehicles. For example, analyzing the bridge for loads from plow trucks loaded with sand or Fire Department water tankers.
• Design and drafting of new bearings.
• Drafting of rehabilitation plans, including demolition extents for the abutments and wingwalls.
Although a full inspection or structural analysis was not conducted, based on the project teams’ initial investigation and experience with similar projects, we are able to draw a number of conclusions and recommendation of potential bridge rehabilitation needs. For this alternative, the project team assumed that the rehabilitated bridge would be rated for H20, which is the equivalent of a 40,000 lbs box truck (see Appendix E). This rating typically allows all Police and Rescue vehicles, but may exclude some Town Maintenance and Fire vehicles. Assuming rehabilitation work progresses after inspection, which is no guarantee as the bridge may be deemed unsalvageable, further anticipated rehabilitation work would include but not be limited to:
• Implementing traffic control measures, such as vehicle barriers, minor signage, and flaggers.
• Implementation of worker safety protection in compliance with current OSHA standards.
• Implementation of an Environmental Protection and Sediment Control plan that includes: o Lead paint removal enclosure and paint capture system o Channel protection during abutment rehabilitation o Sediment control fencing and other measures as required
• Deck Replacement: The existing deck has failed and requires full replacement. The current deck system does not contribute to the bridge’s overall capacity; it only adds dead load to the structure and serves as a driving surface. If rehabilitation is pursued we recommend installing a lighter deck system. Options include:
o Build a nail laminated deck on site made from treated Southern Yellow Pine 2x10’s. These systems are light but also labor intensive and often difficult to build flat. However, this may be an appropriate choice for a low use low capacity structure.
o Install a prefabricated “dowel laminated” wood deck.
o Install a lightweight “exodermic” concrete deck
• Bridge: Some flange and vertical stiffener angles at the girder ends will need replacement. Girder end pates will need replacement. The web will also need spot repairs. Decayed rivets can be replaced with A325 “round head” tension controlled bolts to mimic the look of rivets. 7/8” diameter is a common bolt size for repairs to bridges of this age.
Adams Street Bridge Town of Fair Haven, VT Engineering Study 11 January, 2015
• Bridge Coating: The entire structure will need positive pressure enclosure to capture lead and cleaning to SSPC-SP5 (white metal blast cleaning). To slow decay we recommend the application of an approved three part field applied bridge painting system.
• Bridge Bearings: It is extremely likely that the bearings need replacement. An inexpensive cotton polyester bearing pad such as Sorbtex is recommended on the Adams Street side of the bridge. On the Route 4A side, the project team recommends a bearing pad with a bonded PTFE sheet (low friction resin sheet). Retrofit bearing systems can often be field welded onto existing ones.
• Abutments: Generally the abutments appear structurally sound with the main concerns being deterioration of the concrete and cracking of the Route 4A bridge seat. Because of the high bearing capacity of the ledge below and the low lateral pressures from the old abutment/concrete backfill, it is our opinion that rehabilitation rather than a complete replacement of the abutments is sufficient. It is expected that most abutment work will be limited to chipping away delaminated (failed) concrete and re-surfacing with Gunite (shotcrete). The project team recommends the replacement of the bridge seat on the Route 4A side. The project team also recommends the removal of the curtain walls enclosing the girder ends to allow maintenance of the bridge bearings.
• Bridge Approaches: A change in deck and/or bridge bearings may alter the bridge deck elevation. This would require a limited amount of grading and paving of the approaches.
• Installation of a code compliant pedestrian rails along the top of all wingwalls and the bridge to prevent falls. In addition, consideration should be given to providing pedestrian barriers along the approaches to the bridge.
Advantages:
• Reuses historic structure and maintains bridge as a cultural resource,
• Reopens bridge to vehicle traffic, and
• Continued access to and support of water and sewer utility mains,
Disadvantages:
• Lower capacity than replacement option, with some vehicle restrictions likely, and
• The bridge would require continued maintenance
The total budgetary estimate for this alternative ranges from approximately $1,062,500 to $1,187,500 depending on the extent of required structural repairs. Please refer to Table 1 for additional information.
Adams Street Bridge Town of Fair Haven, VT Engineering Study 12 January, 2015
Table 1: Alternative 2 Budgetary Estimate
Item Description Unit Price
2 Lead Paint Removal LS $285,000
3 Abutment Rehabilitation LS $85,000
4 Bridge Structural Repairs LS $200,000 to $300,000
5 New Bearings LS $30,000
6 New Deck LS $50,000
7 Pedestrian Rails LS $45,000
8 Traffic and Erosion Control LS $50,000
9 Road Approach Work LS $40,000
Construction Total $850,000 to $950,000
Engineering (15%) and Inspection (10%) $212,500 to 237,500
Total Budgetary Estimate $1,062,500 to $1,187,500
3.3 Alternative 3: Rehabilitate the Existing Structure as a Pedestrian Bridge
This alternative is similar to Alternative 2 with similar scope. The advantage to Alternative 3 is that structural repairs to the bridge are likely to be less extensive. Keeping with section 3.4.6 of the VTRANS 2010 Structures Manual, the project team considered rehabilitating the bridge to carry a 20,000 lb. maintenance vehicle and a separate 75 pound per square foot pedestrian load (see Appendix E for proposed bridge details per Figures 3-5 and for design vehicle information). The scope of work for this alternative is similar to Alternative 2 but with the following modifications:
• Bridge deck replacement will consist of a timber deck.
• Installation of traffic bollards on both ends of the bridge to prevent vehicles from crossing the bridge. One or two of the bollards should be removable to allow small maintenance vehicles to cross the bridge. Alternatively, concrete waste blocks can be used to block the bridge and moved by the town with an excavator as required.
Advantages:
• Reuses historic structure and maintains bridge as a cultural resource,
• Continued access to and support of water and sewer utility mains,
Disadvantages:
• Lower capacity than other options,
• Bridge is off a main route and away from downtown, it is unclear that a pedestrian crossing would be used,
• Pedestrian facilities have already been provided on the nearby Route 22A Bridge.
The total budgetary estimate for this alternative ranges from approximately $946,900 to $1,133,700 depending on the extent of required structural repairs. Please refer to Table 2 for additional information.
Adams Street Bridge Town of Fair Haven, VT Engineering Study 13 January, 2015
Table 2: Alternative 3 Budgetary Estimate
Item Description Unit Price
2 Lead Paint Removal LS $285,000
3 Abutment Rehabilitation LS $85,000
4 Bridge Structural Repairs LS $100,000 to $250,000
5 New Bearings LS $30,000
6 New Deck System LS $50,000
7 Pedestrian Rails LS $45,000
8 Traffic and Erosion Control LS $50,000
9 Road Approach Work LS $47,500
Construction Total $757,500 to $907,500
Engineering (15%) and Inspection (10%) $189,400 to $226,200
Total Budgetary Estimate $946,900 to $1,133,700
3.4 Alternative 4: Remove and Replace the Existing Bridge with a New Structure
For Alternative 4, the project team designed a precast concrete beam bridge with composite deck. To minimize cost and reuse existing abutments, we assumed a one lane bridge with no sidewalk. The replacement bridge would be the same width as the existing structure, approximately 12-feet, but with VTrans compliant guardrail. VTrans typically requires that replacement bridges have a minimum width of 16-feet, but this would not be possible with the reuse of the existing abutments. The proposed structure is designed to carry the controlling HL-93 live load required for all new structures by Section 3.4.1 of the 2010 Structures Manual. To reduce cost is was assumed the deck would be to be poured in a single day (see Figure 6 in Appendix E).
A concrete girder bridge was chosen over a steel bridge for a number of reasons:
• Faster, easier, and safer construction
• Lower cost
• Less maintenance
• Longer design life
For this alternative the project team assumed the bridge would be designed to meet AASHTO’s HL-93 design load and expected design life of 75 years. The HL-93 loading is covers a wide variety of vehicles. Designing to this standard allows for all expected maintenance and rescue vehicles to cross the bridge. The expected scope of work for this alternative is:
• Final design of bridge and substructure,
• Implementing traffic control measures, such as vehicle barriers, minor signage, and flaggers,
• Implementation of worker safety protection in compliance with current OSHA standards,
• Implementation of an Environmental Protection and Sediment Control plan that includes,
• Channel protection during abutment rehabilitation,
• Sediment control fencing and other measures as required,
• Partial demolition and removal of the existing bridge and bridge seats,
• Rehabilitation of the abutments,
Adams Street Bridge Town of Fair Haven, VT Engineering Study 14 January, 2015
• Casting of new bridge seats,
• Installation of precast bridge beams,
• Pouring the deck and installing guardrail, and
• Installing recommend code compliant pedestrian railings along the top of all wingwalls to prevent falls.
Advantages:
• Faster construction times,
• Longer life structure with limited maintenance,
• Increase capacity, and
• Continued access to and support of water and sewer utilities
Disadvantages:
• Does not maintain cultural resource of historic structure at that site, which may also result in difficulty utilizing federal funding.
• Removed liability associated with failing bridge, and
• Uncertain that a traffic crossing is needed at this location.
The total budgetary estimate for this alternative is approximately $582,000. Please refer to Table 3 for additional information.
Table 3: Alternative 4 Budgetary Estimate
Item Description Unit Price
9 Road Approach Work LS $40,000
Construction Total $465,000
Total Budgetary Estimate $582,000
3.5 Alternative 5: Removal of Existing Bridge and Construction of Utility/Pedestrian Bridge
This alternative would remove the existing bridge, and install a new bridge with the main purpose of supporting the utility mains over the river. However, the cost for a utility bridge is similar to the cost of a pedestrian bridge. Consequently, a pedestrian bridge capable of supporting the utility mains was considered for this alternative due to the increased functionality at minimal additional cost. The expected scope of work for this alternative is:
• Final design of bridge and substructure,
• Implementing traffic control measures, such as vehicle barriers, minor signage, and flaggers,
Adams Street Bridge Town of Fair Haven, VT Engineering Study 15 January, 2015
• Implementation of worker safety protection in compliance with current OSHA standards,
• Implementation of an Environmental Protection and Sediment Control plan that includes,
• Channel protection during abutment rehabilitation,
• Sediment control fencing and other measures as required,
• Removal of the existing deck, bridge, and bridge seats,
• Rehabilitation of the abutments,
• Installation of pedestrian bridge structure, and
• Installation of pipe hangers and realignment of utilities,
Advantages:
• Lowest cost alternative that provides continued support and access to utility mains,
• Faster construction times,
Disadvantages:
• Does not maintain cultural resource of historic structure at that site, which may also result in difficulty utilizing federal funding.
• Uncertain that a pedestrian bridge is needed at this location.
The total budgetary estimate for this alternative is approximately $393,750. Please refer Table 4 for additional information.
Table 4: Alternative 5 Budgetary Estimate
Item Description Unit Price
4 New Pedestrian Structure LS $145,000
5 Pipe Hangers LS $50,000
Construction Total $315,000
Total Budgetary Estimate $393,750
4.0 PERMITTING Reconstructing, reconditioning or constructing a new bridge in the same general area as the existing bridge would significantly reduce potential impacts to environmental resources. Per preliminary research and coordination, the permitting requirements are similar for each alternative. Permitting is typically conducted during the preliminary design phase of the project and would be dependent on the final design of the alternative selected. The following permits and clearances would be required, at a minimum, for the bridge alternatives investigated:
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o Categorical Exclusion Documentation: If federal funding is obtained for later phases of the project, Categorical Exclusion Documentation would be required to receive clearances for natural and cultural resources per the National Environmental Protection Act. To obtain the Categorical Exclusion clearances, Archeological and Historical Resource and Natural Resources Assessments would be required for the project area.
o VT ANR - Stream Alteration Permit: This permit would be required for any of the alternatives considered due to bridge construction over the Castleton River. Per preliminary coordination with the Vermont State Stream Alteration Engineers, all the alternatives investigated for this study appear eligible for coverage under this permit.
5.0 RECOMMENDATIONS Based on a comprehensive evaluation of the bridge alternatives developed, the project team recommends a combination of Alternative 1: Do Nothing and Permanently Close the Bridge and Alternative 5: Remove Existing Bridge and Replace with Utility/Pedestrian Bridge. Alternative 1 is recommended only as a short term solution. The Town should permanently close the bridge to vehicular traffic and regularly monitor the structure for safety, particularly in respect to pedestrian traffic. The utility hangers should also be inspected on a regular basis to ensure adequacy. Over time, the bridge will continue to deteriorate and will eventually need to be fenced off to completely restrict all access. As the bridge continues to deteriorate, the associated liability for the Town will increase.
In the long term, a plan must be developed for the continued support of the utility mains. Consequently, it is recommended that Alternative 5 be planned and implemented within the next 5 to 10 years. Given the anticipated cost for the replacement pedestrian/pipe bridge, the Town should use this time to line up funding, seek clearances, and plan for this recommended project.
Adams Street Bridge Town of Fair Haven, VT Engineering Study January, 2015
Appendix A
PROJECT SITE
Adams Street Bridge Town of Fair Haven, Vermont
Site Location map July 1986 USGS Map
Adams Street Bridge Town of Fair Haven, VT Engineering Study January, 2015
Appendix B
Vermont AOT Bridge Design Plans (1960)
Adams Street Bridge Town of Fair Haven, VT Engineering Study January, 2015
Appendix C
Inspectiotr Report .for FAIR HAVEN bridge no.: 00004 District: 3
Locoted on: C3050 ove CASTLETON RIVER approximatell, 0.02 MI TO JCT W CL2 TH Owner: 03 TOWN-OWNED
CONDITION
Chanttel Rilittg: I YERY GOOD
Culvert Riling: N NOT APPLICABLE
Federol Str. N u mher : I 01 I 070004 I I 07 I Federal Sulficiency Rating: 074.2
Deticiency Sttlus ofStruclure: FD
Service On: I HIGHWAY
Service Under: 5 WATERWAY
Lanes On lhe Slructure: 0l Lanes Under lhe Slruclure: 00
Bltpnss, Detour Lcngth (niles): 00
ADT: 000640 % Truck ADT: 02
Yeur oI ADT: 2008
Slructure Lenglh (l): 000053
Britlgc RtlwS, Witlth Curb-to-Curh (ft): 12
Deck llidth Out-to-0ut (fi): I3 Appr. Roudwa.y Wirillr (fl): 026
Skew: 00
Bridgc Median: 0 NO MEDIAN
Min Verticul Clr Ot,er (l): 99 FT 99 IN Fenture Under: FEATURE NOT A HIGHWAY
OR RAILROAD Min Verticol Underclr (I): 00 FT 00 IN
STRUCTURE TYPE Qnd MATERIALS
Numher o/ Approtch Spuns 0000 Numher of Main Spans: 001
Kind oJ'Mnleriol and,/or Design: -l STEEL
Deck Structure Tltpe: 1 CONCRETE CIP
Tlpe ol H/euring SurJace: 6 BITaMINOUS
Tlpe of Menfirane 0 NONE
Deck Proleclion: 0 NONE
Transitiotrs: 0 DOES NOT MEET CURRENT STANDARD
Approuclr Guurdroil 0 DOES NOT MEET CURRENT STANDARD
Appnnclt Guardruil Ends: 0 DOES NOT MEET CURRENT STANDARD
Structurul Evoluation: 6 EQAAL TO MINIMaM CRITERIA
Deck Geometry: 2 INTOLERABLE, REPLACEMENT NEEDED
Unrlcrclearunces Verlicnl and Horiuttrtul: N NOT APPLICABLE
llaterwn.y Adequuc.y: 7 SLIGHT CHANCE OF OVERTOPPING BRIDGE & ROADWAY
Appronch Rotrtlwtt.y Alignment: 4 MEETS MINIMUM TOLERABLE CRITERIA
Scour Critical Bridges: 8 STABLE FOR SCOUR
DESIGN VEHICLE, RATING, and POSTING
Lond Rating Method (lnv): 2 ALLOWABLE STRESS (AS)
Postittg Stntus: A OPEN, NO RESTRICTION
Bridge Posting: 5 NO POSTING REQUIRED
Loud Posting: 10 NO LOAD POSTING SIGNS ARE NEEDED
Po,sted Vehicle: POSTING NOT REOUIRED
Posled lleight (lons):
Itrsp. Date: 042012 ltrsp. Freq. (months) 24 X-Ref BrNum:
INSPECTION SUMMARY and NEEDS 04/18/2012 - Regukr inspection utilizing VTrans servi lift unit. Concrete deck needs rehfuititation t ith a rcinlorced oveilay. Deckwenring surface is gelling quite rough and loss of concrete dong the surlace is exposing corroded rebar. The steel superslruclure needs exlensive cleoning anrt painting to slow conosion which is progressing, The southem abutmenl is sound but has some heavy scaling anrl section loss nnd coukl use rcfacing. The taitl up marble relaining wnll flt the southeost cornet of the bfidge is unstable md will likely collnpse into the chtnnel in afew yeus; though ilts eventual fnilure, as ilrith the othet rclaining b'nlls, t't'ill not eflect the bridge. Locals mentionerl lheir concerns legaftling the steep drops offthe ups!rcam side ofthe brirtge, where there is no lype of petleslrinn banier. - MJ/DK
05/18/10 Satisfflctory condilion hov)ever lop of deck conlinues to deleilomte antl needs to be rehabbetl as pol holes are prcsenl flwl exposed rebar is show in rnndom spots. Hewy erosion behind rnil downslrcnm side v,ill need repnirc in lhe not loo disk,nce future an(l unst(ble retaining walts will need. repoir. - MJK/FRE
llerlnesilq, Mnrch 05, 20 1 4
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Photo #4 Rivet pinning
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Photo #6 Deteriorating abutment
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Photo #8 Slate retaining wall
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Appendix D
1,072
54.5
Natural Resources Atlas - Adams Street Bridge Vermont Agency of Natural Resources
750
38.0
1:
WGS_1984_Web_Mercator_Auxiliary_Sphere
Meters38.00
NOTES
LEGEND
19.00
vermont.gov
DISCLAIMER: This map is for general reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. ANR and
the State of Vermont make no representations of any kind, including but not limited to, the warranties of merchantability, or fitness for a particular use, nor
are any such warranties to be implied with respect to the data on this map.
January 14, 2015
1" = 62 1cm = 8Ft. Meters
Dog Sled Trail
Animal
Plant
Acidic Riverside Outcrop
Beaver Wetland (Non-NC)
Black Spruce Swamp
Adams Street Bridge Town of Fair Haven, VT Engineering Study January, 2015
Appendix E
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Figure #3 Schematic Pedestrian Bridge Section – Alternative 3
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