Midtown Corridor Historic Bridge Study Prepared for: Public Works Department City of Minneapolis, Minnesota ___ __, 2007 Prepared by: Project No. 13200.000 SAINT PAUL, MINNESOTA _____ __, 2007 Midtown Corridor Historic Bridge Study Final Report Public Works Department City of Minneapolis, Minnesota CERTIFICATIONS I hereby certify that this report, except those sections specifically listed elsewhere in these certifications, was prepared by me or under my direct supervision and that I am a duly licensed Professional Engineer under the laws of the State of Minnesota. James J. Bellefeuille, P.E. / / Lic. No. 20662 I hereby certify that the sections of this report identified as having been prepared by me were prepared under my direct supervision and that I meet the Secretary of the Interior's Professional Qualifications Standards for Historian and Architectural Historian Charlene Roise / / Midtown Corridor Historic Bridge Study Final Report Midtown Corridor Historic Bridge Study Final Report Public Works Department City of Minneapolis, Minnesota TABLE OF CONTENTS I. EXECUTIVE SUMMARY.................................................................................................1 A. Purpose of and Contributors to the Study................................................................1 B. The Historic District ................................................................................................1 C. Structural Evaluation ...............................................................................................2 D. Current Repair Practices and Feasible New Technologies......................................2 E. Recommendations for Each Bridge, Timeline, and Cost Estimate..........................2 F. Bridge Removal and Impact on the Historic District...............................................3 G. Conclusions..............................................................................................................4 H. Subsequent Steps.....................................................................................................5 II. INTRODUCTION ...............................................................................................................6 A. Project Overview.....................................................................................................6 1. Purpose of the Study ................................................................................... 6 2. Definitions of the Midtown Corridor, Midtown Greenway, and the Historic District........................................................................................... 6 3. Contributors to This Study.......................................................................... 7 B. Bridges Included in the Study..................................................................................8 C. Selection of Bridges for the Study...........................................................................8 D. Research Methods....................................................................................................9 1. Structural Evaluation .................................................................................. 9 2. Historic Study............................................................................................. 9 E. Subsequent Steps.....................................................................................................9 III. CHICAGO MILWAUKEE AND ST. PAUL RAILROAD GRADE SEPARATION HISTORIC DISTRICT ........................................................................................................9 A. Defining Characteristics of the Historic District .....................................................9 B. Origin of the Grade Separation..............................................................................10 C. Original Construction Methods and Materials.......................................................19 Midtown Corridor Historic Bridge Study i Final Report IV. POTENTIAL TRANSIT WITHIN THE RAIL CORRIDOR ...........................................23 A. Light Rail Transit...................................................................................................26 1. Alignment Needs...................................................................................... 26 2. Double Track............................................................................................ 26 3. Platform Arrangements............................................................................. 29 4. Pedestrian Circulation and Access............................................................ 29 5. Impacts to the Greenway Trail.................................................................. 29 B. Modern StreetCar...................................................................................................30 C. Busway...................................................................................................................30 D. Potential Transit—Conclusions.............................................................................30 V. STRUCTURAL EVALUATION......................................................................................30 A. Overview................................................................................................................30 1. Goals ......................................................................................................... 30 2. Methodology of Analysis.......................................................................... 31 3. Available Information............................................................................... 31 B. Description of Bridge Types and Criteria Thresholds ...........................................31 C. Bridge Type Summary...........................................................................................32 1. Cast-in-Place Concrete T-Beams (Structure Type 1) ............................... 32 2. Continuous Concrete Slab Span (Structure Type 2)................................. 32 3. Steel Beam (Structure Type 3).................................................................. 32 4. Post Tensioned Continuous Concrete Slab Span (Structure Type 4) ....... 33 5. Culvert (Structure Type 5)........................................................................ 33 6. Prestressed Concrete Beam and Slab Span (Structure Type 6) ................ 33 7. Concrete Frames (Structure Type 7)......................................................... 33 D. Structural Analysis of Five Representative Bridges ..............................................34 1. Evaluation Process.................................................................................... 34 a. Bridge L8901, Fremont Avenue South..........................................36 b. Bridge L89081, Pleasant Avenue ..................................................44 c. Bridge L8913, Columbus Avenue .................................................50 d. Bridge L8915, 10th Avenue South ................................................56 e. Bridge L8923, 18th Avenue South ................................................61 2. Conclusions............................................................................................... 66 Midtown Corridor Historic Bridge Study ii Final Report VI. CURRENT REPAIR PRACTICES AND NEW TECHNOLOGIES................................66 A. Current Practices....................................................................................................66 1. Shotcrete ................................................................................................... 66 2. Deck Area Patching (Partial- and Full-Depth).......................................... 67 3. Epoxy Injection of Cracks ........................................................................ 67 4. Low Viscosity Sealants and Silane Surface Sealers ................................. 68 5. Deck Drainage Improvements .................................................................. 69 6. Membrane With Asphalt Overlay............................................................. 69 7. Mill and Overlay of Road Surface............................................................ 70 8. High Performance Concrete...................................................................... 70 B. New Technologies.................................................................................................71 1. Reinforcing Bars....................................................................................... 71 a. Steel Bars With Metallic Coating and Alternative Solid Metal Bars ............................................................................71 b. Prefabricated Fusion Bonded Epoxy Coated Reinforcing Bars ............................................................................72 2. Cathodic Protection................................................................................... 72 3. Electrochemical Extraction (ECE)............................................................ 73 4. Strengthening Using Carbon Fiber Reinforced Polymer (CFRP)............. 73 C. CASE STUDIES....................................................................................................74 1. Bridge L8901 - Fremont Avenue.............................................................. 74 2. Bridge L8915 - 10th Avenue .................................................................... 75 3. Bridge L8923 - 18th Avenue .................................................................... 76 VII. RECOMMENDATIONS FOR EACH BRIDGE, TIMELINE,