Minnesota Department of Transportation (MnDOT) Local Historic Bridge Report

Transcription

1 Executive Summary Bridge 93844, or the Columbia Park Bridge, was constructed in 1896 to carry traffic over two tracks of the Soo Line Railway (currently the Canadian Pacific Railway) in Minneapolis. In 1919 the area was converted into the Columbia Golf Course and in the 1930s the bridge was rehabilitated by the Works Progress Administration (WPA). Today, the bridge is owned by the Minneapolis Board of Parks and Recreation. Bridge is significant as one of only two extant steel-arch bridges in Minnesota and as a representative example of the work of the Gillette-Herzog Manufacturing Company. Additionally, the bridge is a contributing resource within the National Register eligible Grand Rounds Historic District. Bridge is a single-span steel deck arch with two approach spans that measures just over 96 feet. The main span is supported on concrete piers/thrust blocks. The superstructure of Bridge is in fair condition and the substructures are in poor condition. This bridge appears to adequately serve its purpose of carrying golf cart and pedestrian traffic. With proper maintenance, stabilization and preservation activities, it is believed Bridge can be restored and continue to serve in its present capacity for 20 years or longer. Any work on Bridge should proceed according to the Secretary of the Interior s Standards for the Treatment of Historic Properties (Standards) [36 CFR part 67] and The Secretary s Standards with Regard to Repair, Rehabilitation, and Replacement Situations, as adapted by the Virginia Transportation Research Council (Guidelines). JULY 2014

2 Bridge Location JULY 2014 Bridge Location

3 Table of Contents Executive Summary Bridge Location I. Project Introduction II. Historic Data III. Bridge Data IV. Existing Conditions/Recommendations V. Projected Costs Appendices A. Glossary B. Guidelines for Bridge Maintenance and Rehabilitation based on the Secretary of the Interior s Standards C. Documents JULY 2014 Table of Contents - i

4 I Project Introduction This Bridge Report is a product of a comprehensive study performed for approximately 140 historic bridges owned by county, city, township, private and other state agencies besides MnDOT. The study is the second phase of a multi-phased process developed and executed in partnership with representatives from the Federal Highway Administration (FHWA); State Historic Preservation Office (SHPO); MnDOT State Aid; MnDOT Cultural Resources Unit (CRU); the US Army Corps of Engineers (USACE); local public works and county highway departments; county and township boards and city councils; the preservation community and the general public. To perform the study, MnDOT retained the consultant team of LHB Inc., Mead & Hunt Inc., and The 106 Group. The general goals of the study include: Gathering and compiling the existing historic and bridge condition data and other relevant information on the bridges in the study group into bridge reports. National Register nominations for a select number of bridges within the study group which the bridge owner may request a nomination to be prepared. Updating MnDOT s Management Plan for Historic Bridges in Minnesota based on the study s findings. Producing a narrative for the MnDOT Historic Bridge Website to disseminate information regarding locally owned historic bridges in Minnesota. Investigating and preparing a summary regarding how other states have funded historic bridge programs and structured Programmatic Agreements when multiple non-state entities are the owners of historic bridges. The Bridge Reports compile and summarize the historic and engineering information concerning the structures. The reports also document the existing use and condition of the bridges along with assessments of the maintenance, stabilization and preservation needs of each structure, including cost estimates. The maintenance activities, along with regular structural inspections and anticipated bridge component replacement activities are routine practices directed toward continued structure serviceability. Stabilization activities address immediate needs identified as necessary to maintain a bridge s structural and historic integrity and serviceability. Preservation activities are near term or long term steps that need to be taken to preserve and in some cases restore a bridge s structural and historic integrity and serviceability. In assessing preservation activities, a design life of 20 years or longer is typically considered. In addition to general restoration activities and dependent on the severity of deterioration, preservation activities may include spot repair, disassembly and reassembly or replacement of specific bridge components. Recommendations within the Bridge Reports are consistent with the Secretary of the Interior s Standards for the Treatment of Historic Properties (Standards). The Standards are basic principles created to help preserve the distinct character of a historic property and its site, while allowing for reasonable change to meet new engineering standards and codes. The Standards recommend repairing, rather than replacing deteriorated features whenever possible. The Standards apply to historic properties of all periods, styles, types, materials and sizes and encompass the property s location and surrounding environment. JULY 2014 Project Introduction I - 1

5 I Project Introduction The Standards were developed with historic buildings in mind and cannot be easily applied to historic bridges. The Virginia Transportation Research Council (Council) adapted the Standards to address the special requirements of historic bridges. They were published in the Council s 2001 Final Report: A Management Plan for Historic Bridges in Virginia, The Secretary s Standards with Regard to Repair, Rehabilitation, and Replacement Situations, provide useful direction for undertaking maintenance, repair, rehabilitation, and replacement of historic bridges and are included in the Appendix to this report. Existing bridge data sources typically available for Minnesota bridges were gathered for the study. These sources include: PONTIS, a bridge management system formerly used by MnDOT to manage its inventory of bridges statewide, and its replacement system, SIMS (Structure Information Management System) The current MnDOT Structure Inventory Report and MnDOT Bridge Inspection Report. Reports are available for the majority of the bridges (not available for bridges in private ownership) Database and inventory forms resulting from the 2012 Minnesota Local Historic Bridge Study and other prior historic bridge studies as incorporated into the database Existing Minnesota historic contexts studies for bridges in Minnesota, including Reinforced- Concrete Highway Bridges in Minnesota, , Minnesota Masonry-Arch Highway Bridges, , Iron and Steel Bridges in Minnesota, and Minnesota Bridges Field investigations documenting the general structural condition and determining characterdefining features Additional data sources researched and gathered for some of the bridges as available also included: Files and records at MnDOT offices Original bridge construction plans, rehabilitation plans, and maintenance records of local owners Files and documents available at the SHPO office, including previous inventory forms, determinations of eligibility, studies, and compliance documents Existing historic and documentary material related to the National Register-eligible bridges The Appendix contains the following: a Glossary explaining structural and historic preservation terms used in the report, the Guidelines for Bridge Maintenance and Rehabilitation based on the Secretary of the Interior s Standards, a list of engineering and historic documents available for this bridge, and copies of the MnDOT Structure Inventory and Bridge Inspection Reports current at the time of the report preparation. The Bridge Report will provide the bridge owner and other interested parties with a comprehensive summary of the bridge condition and detailed information related to the historic nature of the bridge. This information will enable historic bridge owners to make informed decisions when planning for their historic properties. JULY 2014 Project Introduction I - 2

6 II Historic Data This narrative is drawn from previous documents, as available for the subject bridge, which may include determination of eligibility (also known as Phase II evaluation), Minnesota Architecture/History Inventory Form, National Register nomination, Multiple Property Documentation Form, and/or applicable historic contexts. See Sources for details on which documents were used in compiling this Historic Data section. Contractor Designer/Engineer Gillette-Herzog Manufacturing Company, Minneapolis, Minnesota Gillette-Herzog Manufacturing Company, Minneapolis, Minnesota Description Standing on an east-west alignment in the municipal golf course in Columbia Park, the Columbia Park Steel Arch Bridge carries golf cart and pedestrian traffic over a single active track of the Canadian Pacific Railway. Columbia Park is generally bound by Saint Anthony Parkway, Columbia Boulevard, and railroad tracks in the Columbia Park neighborhood in northeast Minneapolis. Constructed in 1896, the 96-footlong bridge has a symmetrical, three-span superstructure consisting of a riveted, 69-foot, double-ribbed, steel deck arch main span flanked by short, concrete-slab approach spans. The two arch ribs in the main span are identically detailed: paired angle sections form the upper and lower chords, which are tied together by a lattice work consisting of paired angle-section verticals and crossed, single, steel bars. The ribs are connected by top-lateral bracing and sway bracing, both consisting of angle sections. At mid-span, the floorbeam rests directly on the arch ribs; otherwise, the ribs support the floorbeams by means of paired, angle-section vertical members, which are sway braced by angle sections. The bridge's deck accommodates a 19-foot roadway between metal lattice-work railings. The railings are 44 inches high and are composed of riveted paired steel angles and flat steel bars to form the lattice-work pattern, with a flat 5-inch-wide plate across the top. The railings are installed in 11-foot-6-inch segments that match the panel spacing on the arch span. The bridge's substructure has been altered several times. In the late 1920s the substructure of the bridge was repaired. In the 1930s concrete wingwalls were constructed and the concrete footings were repaired. The bridge originally had a timber plank deck. In 1976 the deck was replaced with precast, concrete panels supported by rolled I-beam floorbeams, without a stringer system. Currently, the bridge has limestone abutments with concrete wingwalls and four concrete footings. Significance Bridge is located in Columbia Park Golf Course, which is within the Minneapolis Board of Park Commissioner s (Park Board; now Minneapolis Board of Parks and Recreation) park and parkway system. The Park Board was established in 1883 and hired landscape architect Horace Cleveland to design the city s park system, which became known as the Grand Rounds. The Grand Rounds is a series of interconnected parks, parkways lakes, rivers, creeks, and other natural features encircling the city. Development of the city s park and parkways began in earnest in the late nineteenth century and continued to be developed and expanded throughout the twentieth century. In 2012 the Grand Rounds JULY 2014 Historic Data II - 3

7 II Historic Data was determined eligible for listing in the National Register. Bridge is a contributing resource within the district. The Park Board acquired land for Columbia Park in the city's northeast corner in The initial improvement plan called for the construction of a modest network of boulevards, including a carriage bridge over the Soo Line Railway corridor that cut through the east part of the grounds. In 1894 the Park Board invited bridge builders to submit designs for the Columbia Park crossing. Five firms responded with a total of nine plans ranging in price from $1,097 to $1,849. None proved satisfactory. After shelving the project for a year, the board once again solicited proposals, this time restricting the bidding to a predetermined steel-arch design with a not-to-exceed cost of $3,500. Under these new guidelines, the board, in May 1896, awarded a construction contract to the Gillette-Herzog Manufacturing Company of Minneapolis, the lowest bidder at $1,435. The bridge was completed before the end of the year. By 1919 a six-hole golf course was added to the grounds, which became very popular. "Columbia Park," announced the Park Board in its year-end report for 1920," is coming rapidly to the front as one of the most useful parks of the system." In November 1926 the Soo Line notified the Park Board "that the steel arch plank deck highway bridge built over its tracks in Columbia Park was in need of repair." After conducting its own investigation, the Park Board agreed, but was of the opinion that the railroad should underwrite the work. When the Soo Line refused, the Board brought suit against the railroad. In the spring of 1929 the matter was settled out of court, with the city agreeing to pay the cost of the repairs and the railroad agreeing to share the cost of future maintenance. Although surviving documents do not discuss the nature of the repair work, fieldinspection evidence suggests that parts of the bridge's substructure were rebuilt. Later work to the substructure was undertaken by the Work Projects Administration (WPA) as part of its work on the Columbia Park Golf Course. In 1937 concrete wingwalls were installed and in 1939 the bridge s four concrete footings were reconstructed due to deterioration. By 1958, in its annual report, the board announced that "the steel arch bridge which was constructed in 1896 was found to have deteriorated and to be in hazardous condition. The bridge has been closed to vehicular traffic, but is still open for use by pedestrians." In 1976, new precast concrete slabs were constructed as approach spans on each side of the arch span. A concrete bench was placed on the top of each abutment to support the new slab approach spans. Also at the time, the arch span s deck and floor system were rebuilt. The bridge is currently open to golf cart and pedestrian traffic. Bridge remains in its original location over the Canadian Pacific Railway (historically the Soo Line Railway) in Columbia Park in Minneapolis. As such, the bridge retains integrity of location. It also retains reasonably good integrity of setting. The area around it, though developed into a golf course, is still part of Columbia Park. Therefore, Bridge retains integrity of setting. Despite several rehabilitations, including in the late 1920s, 1930s, and 1976, none of the modifications undertaken during the rehabilitation efforts affected the original design of the steel arch span. Therefore, the bridge retains sufficient integrity of design, materials, and workmanship. Bridge also retains sufficient integrity of feeling and association, despite its conversion from vehicular use to pedestrian and golf cart use. The period of significance for this bridge is 1896, which corresponds to the year the bridge was built. JULY 2014 Historic Data II - 4

8 II Historic Data The Columbia Park Bridge is significant under National Register Criterion C in the area of Engineering, within the historic context of the Iron and Steel Bridges Multiple Property Documentation Form (MPDF), as a rare example of a steel arch bridge built in the 1890s by the Gillette-Herzog Manufacturing Company, an important fabricator. Additionally, Bridge is a contributing resource within the National Register-eligible Grand Rounds Historic District. Historic Context Iron and Steel Bridges in Minnesota, ; Federal Relief Construction in Minnesota, National Register Status Criterion A Significance Criterion C Significance Historic District SHPO inventory number Eligible (Individually); Contributing to Eligible Historic District N/A Engineering: Important type; Work of a master Grand Rounds HE-MPC-9005 Sources Used to Compile Section II Historic Data Bridge electronic record in the Minnesota Department of Transportation Bridge Database. Bridge File, in Minnesota Department of Transportation, Waters Edge Building, St. Paul, Minn. Bridge File, in Minneapolis Department of Public Works, City of Lakes Building, Minneapolis. Mead & Hunt, Inc. Bridge Minnesota Architecture History Inventory Form. Prepared for MnDOT (June 2014). Minneapolis Board of Park Commissioners. Annual Reports, 1921 (pp ), 1920 (p. 20), 1927 (p. 80), and 1958 (p. 51). Minneapolis Board of Park Commissioners. Proceedings, 1894 (p. 70), 1896 (pp. 34, 38), 1926 (p. 152), 1927 (pp ), 1929 (pp.46, 88), 1976 (137). Available in the Municipal Information Public Library, Minneapolis City Hall. Minneapolis Board of Park Commissioners. The Story of the W.P.A. In the Minneapolis Parks, Parkways, and Playgrounds for 1937 (p. 25). Available at the Minneapolis Park Board Office, Minneapolis. Minneapolis Board of Park Commissioners. The Story of the W.P.A. In the Minneapolis Parks, Parkways, and Playgrounds for 1939 (p. 20). Available at the Minneapolis Park Board Office, Minneapolis. Minnesota Department of Transportation Bridge Database. JULY 2014 Historic Data II - 5

9 II Historic Data Quivik, Fredric L. "Iron and Steel Bridges in Minnesota." Multiple Property Documentation Form, 1988, Sec. F, 9. Available in the State Historic Preservation Office, Minnesota Historical Society, St. Paul, Minn. Wirth, Theodore. Minneapolis Park System N.p.: Minneapolis Board of Park Commissioners, 1945, 63-64, Field inspection by Chad Perkins, 7 October Field inspection by Jeffrey A. Hess, 28 August Field inspection by Mead & Hunt, 15 October 2013 and 5 November JULY 2014 Historic Data II - 6

10 II Historic Data Character-Defining Features Character-defining features are prominent or distinctive aspects, qualities, or characteristics of a historic property that contribute significantly to its physical character. Features may include materials, engineering design, and structural and decorative details. Often, the character-defining features include important historic fabric. However, historic fabric can also be found on other elements of a bridge that have not been noted as character-defining. For this reason, it is important to consider both characterdefining features and the bridge s historic fabric when planning any work. Feature 1: Design and construction of a single-span steel deck arch bridge built in the 1890s by the Gillette-Herzog Manufacturing Company, an important fabricator. This feature includes modifications, including concrete wingwalls and footing work during the 1920s by the City and Railroad and in the 1930s by the WPA. JULY 2014 Historic Data II - 7

11 II Historic Data Feature 2: Setting within Columbia Golf Course, a contributing resource to the National Registereligible Grand Rounds. JULY 2014 Historic Data II - 8

12 III Bridge Data Date of Construction (remodel) 1896 Common Name (if any) Columbia Park Bridge Location Feature Carried: PED-MAINT Feature Crossed: CP Rail County: Hennepin Ownership: Mpls Park Board MnDOT Structure Data *Data Current (as of): Sep 2013 Main Span Type: 312 STEEL ARCH Main Span detail: Substructure Type - Foundation Type: Abutment: 6-Combination - 0-Unknown Piers: 6-Combination - 0-Unknown Total Length: 96.5 ft Main Span Length: 67 ft Total Number of Span(s): 3 Skew (degrees): 0 Structure Flared: No Flare Roadway Function: PED Custodian/Maintenance Type: Local Park Reported Owner Inspection Date 11/1/2012 Sufficiency Rating N/A Operating Rating PED Inventory Rating PED Structure Status A - Open Posting VEH: SEMI: DBL: Design Load PED Current Condition Code Roadway Clearances Deck: 7 Roadway Width: N/A Superstructure: 6 Vert. Clearance Over Rdwy: N/A Substructure: 4 Vert. Clearance Under Rdwy: N/A Channel and Protection: N Lat. Clearance Right: 0 ft Culvert: N Lat. Clearance Left: 0 ft Current Appraisal Rating Roadway Data Structural Evaluation: N ADT Total: 1 (2009) Deck Geometry: N Truck ADT Percentage: Not given Underclearances: 4 Bypass Detour length: 1 miles Waterway Adequacy: N Number of Lanes: 0 Approach Alignment: N Fracture Critical No Waterway Data Deficient Status N/A (PED) Scour Code: A-NON WATERWAY Non-MnDOT Data Approach Roadway Characteristics **Number of Crashes reported Lane Widths: N/A (PED) in MnMCAT within 500 feet Shoulder Width: N/A (PED) of Bridge Site N/A (PED) Shoulders Paved or Unpaved: N/A (PED) Roadway Surfacing: N/A (PED) Location of Plans Plans Available Minneapolis Park Board 1894 Original Schematic * Non-MnDOT data collected during field survey. All other fields of data collected from MnDOT September of See Appendix C for MnDOT inventory and inspection report data. ** Unless a significant number of crashes are noted on or near a bridge, the accident data is not detailed in this report. JULY 2014 Bridge Data III - 9

13 IV Existing Conditions/Recommendations Existing Conditions Available information, as detailed in the Project Introduction section, concerning Bridge 1238 was reviewed prior to visiting the bridge site. The site visit was conducted to establish the following: 1. General condition of structure 2. Conformation to available extant plans 3. Current use of structure 4. Roadway/pedestrian trail geometry and alignment (as applicable) 5. Bridge geometry, clearances and notable site issues General Bridge Description Bridge is located in a municipal golf course in Columbia Park in northeast Minneapolis, and carries golf cart and pedestrian traffic over a single, active track of the Canadian Pacific Railway. This bridge is a three-span structure with a length of 96 feet 6 inches. The bridge consists of one 69-foot-long, doubleribbed, riveted, steel deck arch main span and two 13-foot-long, 9-inch-thick concrete slab approach spans, one on each end of the main span. The deck consists of ten 24-inch-wide precast concrete panels placed side by side, resulting in a deck width of 20 feet. The concrete panels were constructed in 1976 to replace a timber plank deck. The concrete panels are supported on rolled I-section floorbeams on the arch span. The concrete panels for the approach spans are supported on the end floorbeams of the arch span and on limestone abutments with concrete caps. The concrete caps were also constructed in The arch span is supported on concrete piers/thrust blocks located at each corner of the span. The east abutment is constructed of limestone segments with a concrete cap to support the concrete panels. The west abutment is constructed of large concrete blocks that support limestone segments with a concrete cap to support the concrete panels. Flared, concrete wingwalls were constructed at each abutment in the 1920s. A 44-inch-high steel lattice-work railing is located on each edge of the bridge. The approach roadways to the bridge consist of a thin asphalt surface over gravel base. There are no guardrails on the east approach roadway. For the west approach roadway, a single line timber rail exists on the north side. A new two-line timber railing is located on the south side. Serviceability Observations The bridge is currently open to golf cart and pedestrian traffic in the Columbia Golf Club. The bridge is located over an active track of the Canadian Pacific Railway. Superstructure The concrete deck panels are in good condition overall, with minor scaling. The sealant in the joints between the panels is in poor condition, with loss of sealant adhesion in portions of the joints. Water seepage through the joints was observed on the underside of the concrete panels, especially at each abutment. The arches of the riveted steel arch main span are in fair condition. The arch span has not been painted for many years; the paint condition is poor. Pack rust was observed in crevices of the connections and arch members, with some minor section loss. JULY 2014 Existing Conditions/Recommendations IV - 10

14 IV Existing Conditions/Recommendations The four bearings of the arches are in good condition overall with some rusting. The paint condition is fair for all the bearings. The bearing pins appear to be in fair condition based on visual observation. The steel floorbeams are in fair condition. The paint condition is poor. There is moderate rust on the top and bottom flanges of the floorbeams, with moderate pack rust in the crevices and some minor section loss in the bottom flanges. The steel spandrel columns are in fair condition. The paint condition is poor. There is pack rust at the connections causing some minor separation in the crevices. The secondary elements of the arch span (diaphragms and sway bracing) are in fair condition. The paint condition is poor. There is some pack rust at the connections and minor section loss on horizontal surfaces. The steel lattice-work railings on each side of the bridge are in fair condition. The paint condition is poor, with moderate rust and pack rust at many riveted connections and crevices. Open joints ranging from one-quarter-inch to 2 inches exist between the railing sections. At some of the joints, plates have been welded on the top member of the railings to prevent the railing joints from opening further. At some other locations, bolts have been installed to prevent the joints from opening further. The south railing is bowed outward near the middle of the span. An 8-inch diameter metal utility pipe is supported on the surface of the south side of the bridge deck. This pipe goes underground at each end of the bridge. A 1.5-inch PVC conduit also is supported on the south side of the bridge deck next to the utility pipe. Both of these items are in good condition. Inspection reports indicate that these items may have been installed in Substructure The east abutment is in poor condition. The stones are heavily weathered with some cracking. Mortar in the joints between the stones is severely deteriorated and missing in nearly 100 percent of the surface area. An approximate 2-foot by 3-foot area of the abutment surface was patched with concrete. The concrete patch does not match the appearance or texture of the abutment stone. The concrete northeast wingwall is in fair condition. The concrete southeast wingwall is in fair condition. The west abutment is in very poor condition. There are areas of missing or badly deteriorated stones in approximately 20 percent of the surface area. The stones are heavily weathered with some cracking. Mortar in the joints between the stones is severely deteriorated and missing in nearly 100 percent of the surface area. There is undermining and settlement of the concrete blocks with some loss of bearing. Seepage from behind the abutment was observed and may be a cause of the undermining. Movement of the west abutment has been monitored since According to the most recent inspection report, the south end has moved a total of 8-1/4 inches, the middle has moved a total of 3 and one-quarter inches and the north end has moved a total of 1 and three-eighths inches. The concrete northwest wingwall is in fair condition. The concrete southwest wingwall is in fair condition. The foundations for the abutments and wingwalls are unknown. JULY 2014 Existing Conditions/Recommendations IV - 11

15 IV Existing Conditions/Recommendations The four concrete piers/thrust blocks for the arch span bearings are in good condition with some minor surface cracking. The foundation is unknown for these piers/thrust blocks. Approach Roadways and Guardrails The approach roadway at each end of the bridge is in fair condition. The asphalt placed over the gravel base is spalled and cracked. Asphalt at the west approach is uneven and does not cover the entire surface of the gravel base. There are no guardrails on the east approach roadway to the bridge. At the west approach roadway, a single line timber railing on the north side is in poor condition with moderate rotting. A new two-line timber railing was recently installed on the south side. Date of Engineering Site Visit by Mead & Hunt October 15, 2013 and November 5, 2013 JULY 2014 Existing Conditions/Recommendations IV - 12

16 IV Existing Conditions/Recommendations Condition 1: West approach to bridge, looking east (note condition of roadway surface and condition of timber guardrails each side of roadway) Condition 2: East approach to bridge, looking west (note condition of roadway surface and no guardrails) JULY 2014 Existing Conditions/Recommendations IV - 13

17 IV Existing Conditions/Recommendations Condition 3: View of deck and railing, looking east (note condition of joints between concrete deck panels; also note utility pipe on south side of deck) Condition 4: South elevation of bridge, looking north JULY 2014 Existing Conditions/Recommendations IV - 14

18 IV Existing Conditions/Recommendations Condition 5: East abutment and east piers/thrust blocks for arch span (note condition of steel in arch span, floorbeams diaphragms and bracing) Condition 6: East abutment (note cracks in stones and condition of mortar joints; note concrete patch) JULY 2014 Existing Conditions/Recommendations IV - 15

19 IV Existing Conditions/Recommendations Condition 7: East abutment, southeast wingwall (note condition of stones and mortar joints) Condition 8: Underside of bridge over RR tracks (note soot on concrete deck; note bow in railing) JULY 2014 Existing Conditions/Recommendations IV - 16

20 IV Existing Conditions/Recommendations Condition 9: West abutment and west piers/thrust blocks for arch span Condition 10: West abutment (note condition of stones and concrete blocks and undermining of footings) JULY 2014 Existing Conditions/Recommendations IV - 17

21 IV Existing Conditions/Recommendations Condition 11: West abutment (note movement of blocks and deteriorated condition of stones and joints) Condition 12: Underside of deck at west abutment (note water leakage at joints in deck panels and leakage onto steel floorbeams) JULY 2014 Existing Conditions/Recommendations IV - 18

22 IV Existing Conditions/Recommendations Condition 13: North railing, showing condition of railing and gap between sections Condition 14: South railing, showing condition of railing and gap between sections JULY 2014 Existing Conditions/Recommendations IV - 19

23 IV Existing Conditions/Recommendations Overall Recommendations The bridge is currently open to pedestrian and golf cart traffic in the Columbia Golf Course. The recommendations which follow assume the structure s use will remain the same. Any stabilization or preservation activities will need to be coordinated with the Canadian Pacific Railway because the track is active. Flagging and other coordination would be required. Recommended Stabilization Activities No stabilization repairs are recommended. The condition of the west abutment foundation should be monitored frequently (more often than 12 months), especially during and after a heavy rain event. It is noted that this bridge is inspected on a 12 month cycle, and may need more frequent inspections. An indepth study of condition of the foundation of the west abutment is beyond the scope of this study. But as a stabilization activity, it is recommended that such a study be implemented within the next 12 months, Recommended Preservation Activities 1. Construct reinforcement for west abutment. This work would consist of replacing deteriorated stones as described in Item 2 below, and repoint all mortar joints for the stones as described in Item 3 below. This work would also consist of shotcrete repair to the concrete blocks, particularly the joints between the blocks and at the base of the blocks. The shotcrete work would need to be conducted in a manner to restore the original surface finish, color, texture and jointing of the concrete blocks. 2. Replace deteriorated stones in east abutment with stones of similar composition, size, strength, color and texture. It is assumed that quarried stone of the type, color range, shape and crafted texture to the original is still available. 3. Repoint all mortar joints in stones for east abutment. Since it is unlikely any of the original stone mortar is still present or competent enough for testing the mortar selection and finished tooling will need to be based on both a study of what mortar may be remaining, the requirements of the replacement stone and historic information regarding this and similar structures. To maintain historic integrity it will also be necessary for the project construction details to fully define the repointing requirements including but not limited to such items as joint preparation, mortar finish and tooling, mortar curing, and preparation of repointing test panels. 4. Clean and repaint the entire arch span superstructure, including the metal railings on the arch span and on the approach spans. The current paint system on the arch span is failed and the system should be replaced. It is recommended the in-place paint system be entirely removed to bare metal through abrasive blasting (blast media and technique tested to ensure it does not damage sound structure which is to remain). Following removal, the structure should be painted with a zinc-rich primer and a protective overcoat system with color and sheen to be selected based on a study of preservation standards. The in-place system will require testing for the presence of lead. Due to the toxicity of lead, the removal of a lead-based paint system requires an intensive encapsulation process. For purposes of cost estimating, a lead-based system has been presumed. JULY 2014 Existing Conditions/Recommendations IV - 20

24 IV Existing Conditions/Recommendations Recommended Annual Maintenance Activities 1. Reseal joints between precast concrete deck panels. 2. Repair connections between railing segments with bolted or welded plate connections at 14 joints between the railing panels. 3. Reseal asphalt in roadway approaches at each end of bridge. 4. Monitor condition of stones and joints in east and west abutments in annual bridge inspections. 5. Monitor condition of west abutment for movement in annual bridge inspections. 6. Construct timber railing on north and south sides of east approach roadway. 7. Remove existing timber railing and construct new timber railing on north side of west approach roadway. JULY 2014 Existing Conditions/Recommendations IV - 21

25 V Projected Costs Summarized Maintenance, Stabilization and Preservation Construction Cost Estimates It is important to recognize that the work scope and cost estimates presented herein are based on a limited level assessment of the existing structure. In moving forward with future project planning, it will be essential to undertake a detailed structure assessment addressing the proposed work for the structure. It is also important that any future preservation work follow applicable preservation standards with emphasis to rehabilitate and repair in-place structure elements in lieu of replacement. This includes elements which are preliminarily estimated for replacement within the work scope of this report. Only through a thorough review of rehabilitation and repair options and comprehensive structural and historic assessment can a definitive conclusion for replacement of historic fabric be formed. The opinions of probable construction and administrative costs provided below are presented in 2013 dollars. These costs were developed without benefit of a detailed, thorough bridge inspection, bridge survey or completion of preliminary design for the estimated improvements. The estimated costs represent an opinion based on background knowledge of historic unit prices and comparable work performed on other structures. The opinions of cost are intended to provide a programming level of estimated cost. These costs will require refinement and may require significant adjustments as further analysis is completed in determining the course of action for future structure improvements. A 20 percent contingency and 7 percent mobilization allowance has been included in the construction cost estimates. Administrative and engineering costs are also presented below. Engineering and administrative costs are also to be interpreted as programming level only. Costs can be highly variable and are dependent on structure condition, intended work scope, project size and level of investigative, testing and documentation work necessary. Additional studies, evaluation, and historic consultation costs not exclusively called out may also be incurred on a case-by-case basis. Maintenance, Stabilization and Preservation Costs (refer to the work item breakdown on the next page) Opinion of Annual Cost- Maintenance Activities: $ 8,540 Opinion of Construction Cost- Stabilization Activities: $ 0 Opinion of Construction Cost- Preservation Activities: $ 445,600 Estimated Preliminary Design, Final Design, Construction Administration Costs Preliminary Design and Assessment $ 9,000 Final Design and Plans $ 45,000 Construction Administration $ 55,000 JULY 2014 Projected Costs V - 22

26 V Projected Costs MAINTENANCE, STABILIZATION & PRESERVATION COST ESTIMATE (2013 DOLLARS) Bridge No July 7, 2014 ESTIMATED QUANTITIES AND COST ITEM NO. MAINTENANCE COSTS ITEM 1 RESEAL JOINTS BETWEEN PRECAST CONCRETE DECK PANELS LIN FT 864 $2.50 $2, REPAIR CONNECTIONS BETWEEN STEEL RAILING SEGMENTS EACH 14 $ $1, UNIT QUANTITY UNIT COST TOTAL ESTIMATE 3 RESEAL ASPHALT ROADWAY APPROACHES AT EACH END OF BRIDGE 4 CONSTRUCT TIMBER RAILING ON NORTH AND SOUTH SIDES OF EAST APPROACH ROADWAY 5 REMOVE EXISTING TIMBER RAILING; CONSTRUCT NEW TIMBER RAILING ON NORTH SIDE OF WEST APPROACH ROADWAY EACH 2 $ $1, LIN FT 80 $20.00 $1, LIN FT 40 $22.00 $ % CONTINGENCY LUMP SUM 1 $1, $1, STABILIZATION COSTS ESTIMATED MAINTENANCE COSTS $8, NO STABILIZATION ACTIVITIES ARE RECOMMENDED PRESERVATION COSTS ESTIMATED STABILIZATION COSTS $0.00 7% LUMP SUM 1 $29, $29, CONSTRUCT REINFORCEMENT FOR WEST ABUTMENT LUMP SUM 1 $100, $100, REPLACE DETERIORATED STONES IN EAST ABUTMENT SQ FT 400 $ $80, REPOINT MORTAR JOINTS IN STONES FOR EAST ABUTMENT SQ FT 400 $30.00 $12, CLEAN AND REPAINT ENTIRE ARCH SPAN STEEL AND ALL LUMP SUM 1 $80, $80, RAILINGS, ASSUME CONTAINMENT REQUIRED FOR LEAD ABATEMENT 5 RAILROAD COORDINATION AND FLAGGING LUMP SUM 1 $75, $75, % CONTINGENCY LUMP SUM 1 $69, $69, ESTIMATED PRESERVATION COSTS $445, JULY 2014 Projected Costs V - 23

27 Appendices Appendix A. Glossary JULY 2014 Appendices - 24

28 Glossary Abutment Component of bridge substructure at either end of bridge that transfers load from superstructure to foundation and provides lateral support for the approach roadway embankment. Appraisal ratings Five National Bridge Inventory (NBI) appraisal ratings (structural evaluation, deck geometry, under-clearances, waterway adequacy, and approach alignment, as defined below), collectively called appraisal ratings, are used to evaluate a bridge s overall structural condition and loadcarrying capacity. The evaluated bridge is compared with a new bridge built to current design standards. Ratings range from a low of 0 (closed bridge) to a high of 9 (superior). Any appraisal item not applicable to a specific bridge is coded N. Approach alignment One of five NBI inspection ratings. This rating appraises a bridge s functionality based on the alignment of its approaches. It incorporates a typical motorist s speed reduction because of the horizontal or vertical alignment of the approach. Character-defining features Prominent or distinctive aspects, qualities, or characteristics of a historic property that contribute significantly to its physical character. Features may include structural or decorative details and materials. Condition, fair A bridge or bridge component of which all primary structural elements are sound, but may have minor deterioration, section loss, cracking, spalling, or scour. Condition, good A bridge or bridge component which may have some minor deficiencies, but all primary structural elements are sound. Condition, poor A bridge or bridge component that displays advanced section loss, deterioration, cracking, spalling, or scour. Condition rating Level of deterioration of bridge components and elements expressed on a numerical scale according to the NBI system. Components include the substructure, superstructure, deck, channel, and culvert. Elements are subsets of components, e.g., piers and abutments are elements of the component substructure. The evaluated bridge is compared with a new bridge built to current design standards. Component ratings range from 0 (failure) to 9 (new) or N for (not applicable); elements are rated on a scale of 1-3, 1-4 or 1-5 (depending on the element type and material). In all cases condition state 1 is the best condition with condition state 3, 4 or 5 being the worst condition. In rating a bridge s condition, MnDOT pairs the NBI system with the newer and more sophisticated Pontis element inspection information, which quantifies bridge elements in different condition states and is the basis for subsequent economic analysis. Corrosion The general disentegration of metal through oxidation. Cutwater The wedge-shaped end of a bridge pier, designed to divide the current and break up ice.

29 Decay Deterioration of wood as a result of fungi feeding on its cell walls. Delamination Surface separation of concrete, steel, glue laminated timber plies etc. into layers. Deck geometry One of five NBI appraisal ratings. This rating appraises the functionality of a bridge s roadway width and vertical clearance, taking into account the type of roadway, number of lanes, and ADT. Deficiency The inadequacy of a bridge in terms of structure, serviceability, and/or function. Structural deficiency is determined through periodic inspections and is reflected in the ratings that are assigned to a bridge. Service deficiency is determined by comparing the facilities a bridge provides for vehicular, bicycle, and pedestrian traffic with those that are desired. Functional deficiency is another term for functionally obsolete (see below). Remedial activities may be needed to address any or all of these deficiencies. Deficiency rating A nonnumeric code indicating a bridge s status as structurally deficient (SD) or functionally obsolete (FO). See below for the definitions of SD and FO. The deficiency rating status may be used as a basis for establishing a bridge s eligibility and priority for replacement or rehabilitation. Design exception A deviation from federal design and geometric standards that takes into account environmental, scenic, aesthetic, historic, and community factors that may have bearing upon a transportation project. A design exception is used for federally funded projects where federal standards are not met. Approval requires appropriate justification and documentation that concerns for safety, durability, and economy of maintenance have been met. Design load The usable live-load capacity that a bridge was designed to carry, expressed in tons according to the AASHTO allowable stress, load factor, or load resistance factor rating methods. An additional code was recently added to assess design load by a rating factor instead of tons. This code is used to determine if a bridge has sufficient strength to accommodate traffic load demands. A bridge that is posted for load restrictions is not adequate to accommodate present or expected legal truck traffic. Deterioration Decline in condition of surfaces or structure over a period of time due to chemical or physical degradation. Efflorescence A deposit on concrete or brick caused by crystallization of carbonates brought to the surface by moisture in the masonry or concrete. Extant Currently or actually existing. Extrados The upper or outer surfaces of the voussoirs which compose the arch ring. Often contrasted with intrados.

30 Footing The enlarged, lower portion of a substructure which distributes the structure load either to the earth or to supporting piles. Fracture Critical Members Tension members or tension components of bending members (including those subject to reversal of stress) whose failure would be expected to result in collapse of the bridge. Functionally obsolete The Federal Highway Administration (FHWA) classification of a bridge that does not meet current or projected traffic needs because of inadequate horizontal or vertical clearance, inadequate load-carrying capacity, and/or insufficient opening to accommodate water flow under the bridge. An appraisal rating of 3 or less for deck geometry, underclearance, approach alignment, structural evaluation or waterway adequacy will designate a bridge as functionally obsolete. Gusset plate A plate that connects the horizontal and vertical members of a truss structure and holds them in correct position at a joint. Helicoidal Arranged in or having the approximate shape of a flattened coil or spiral. Historic fabric The material in a bridge that was part of original construction or a subsequent alteration within the historic period of the bridge (i.e., more than 50 years old). Historic fabric is an important part of the character of the historic bridge and the removal, concealment, or alteration of any historic material or distinctive engineering or architectural feature should be avoided if possible. Often, the characterdefining features include important historic fabric. However, historic fabric can also be found on other elements of a bridge that have not been noted as character-defining. Historic bridge A bridge that is listed in, or eligible for listing in, the National Register of Historic Places. Historic integrity The authenticity of a bridge s historic identity, evidenced by the survival and/or restoration of physical characteristics that existed during the bridge s historic period. A bridge may have integrity of location, design, setting, materials, workmanship, feeling, and association. Inspections Periodic field assessments and subsequent consideration of the fitness of a structure and the associated approaches and amenities to continue to function safely. Intrados The innner or lower surface of an arch. Often contrasted with extrados. Inventory rating The load level a bridge can safely carry for an indefinite amount of time expressed in tons or by the rating factor described in design load (see above). Inventory rating values typically correspond to the original design load for a bridge without deterioration. Keystone Wedge-shaped stone, or voussoir, at the crown of an arch.

31 Load Rating The determination of the live load carrying capacity of a bridge using bridge plans and supplemented by field inspection. Maintenance Work of a routine nature to prevent or control the process of deterioration of a bridge. Minnesota Historical Property Record A documentary record of an important architectural, engineering, or industrial site, maintained by the Minnesota Historical Socitety as part of the state s commitment to historic preservation. MHPR typically includes large-format photographs and written history, and may also include historic photographs, drawings, and/or plans. This state-level documentation program is modeled after a federal program known as the Historic American Buildings Survey/Historic American Engineering Record (HABS/HAER). National Bridge Inventory Bridge inventory and appraisal data collected by the FHWA to fulfill the requirements of the National Bridge Inspection Standards (NBIS). Each state maintains an inventory of its bridges subject to NBIS and sends an annual update to the FHWA. National Bridge Inspection Standards Federal requirements for procedures and frequency of inspections, qualifications of personnel, inspection reports, and preparation and maintenance of state bridge inventories. NBIS applies to bridges located on public roads. National Register of Historic Places The official inventory of districts, sites, buildings, structures, and objects significant in American history, architecture, archaeology, and culture, which is maintained by the Secretary of the Interior under the authority of the National Historic Preservation Act of 1966 (as amended). Non-vehicular traffic Pedestrians, non-motorized recreational vehicles, and small motorized recreational vehicles moving along a transportation route that does not serve automobiles and trucks. Includes bicycles and snowmobiles. Operating rating Maximum permissible load level to which a bridge may be subjected based on a specific truck type, expressed in tons or by the rating factor described in design load (see above). Pack rust Rust forming between adjacent steel surfaces in contact which tends to force the surfaces apart due to the increase in steel volume. Pier A substructure unit that supports the spans of a multi-span superstructure at an intermediate location between its abutments. Pointing The compaction of mortar into the outermost portion of a joint and the troweling of its exposed surface to secure water tightness and/ or desired architectural effect (when replacing deteriorated mortar).

32 Pony truss A through bridge with parallel chords and having no top lateral bracing over the deck between the top chords. Posted load Legal live-load capacity for a bridge which is associated with the operating rating. A bridge posted for load restrictions is inadequate for legal truck traffic. Pontis Computer-based bridge management system to store inventory and inspection data and assist in other bridge data management tasks. Preservation Preservation, as used in this report, refers to historic preservation that is consistent with the Secretary of the Interior s Standards for the Treatment of Historic Properties. Historic preservation means saving from destruction or deterioration old and historic buildings, sites, structures, and objects, and providing for their continued use by means of restoration, rehabilitation, or adaptive reuse. It is the act or process of applying measures to sustain the existing form, integrity, and material of a historic building or structure, and its site and setting. MnDOT s Bridge Preservation, Improvement and Replacement Guidelines describe preservation differently, focusing on repairing or delaying the deterioration of a bridge without significantly improving its function and without considerations for its historic integrity. Preventive maintenance The planned strategy of cost-effective treatments that preserve a bridge, slow future deterioration, and maintain or improve its functional condition without increasing structural capacity. Reconstruction The act or process of depicting, by means of new construction, the form, features, and detailing of a non-surviving site, landscape, building, structure, or object for the purpose of replicating its appearance at a specific period of time and in its historic location. Activities should be consistent with the Secretary of the Interior s Standards for the Treatment of Historic Properties. Rehabilitation The act or process of returning a historic property to a state of utility through repair or alteration which makes possible an efficient contemporary use, while preserving those portions or features of the property that are significant to its historic, architectural, and cultural values. Historic rehabilitation, as used in this report, refers to implementing activities that are consistent with the Secretary of the Interior s Standards for the Treatment of Historic Properties. As such, rehabilitation retains historic fabric and is different from replacement. MnDOT s Bridge Preservation, Improvement and Replacement Guidelines describe rehabilitation and replacement in similar terms. Restoration The act or process of accurately depicting the form, features, and character of a property as it appeared at a particular period of time. Activities should be consistent with the Secretary of the Interior s Standards for the Treatment of Historic Properties. Ring stone One of the separate stones of an arch that shows on the face of the headwall, or end of the arch. Also known as a voussoir.