State of Wisconsin/Department of Transportation RESEARCH PROGRESS REPORT FOR THE QUARTER ENDING: June 30, 2009

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1 State of Wisconsin/Department of Transportation RESEARCH PROGRESS REPORT FOR THE QUARTER ENDING: 30, 2009 Program: SPR-0010(36) FFY99 Part: II Research and Development Project Title: Rational System for Rating WI Bridges Project ID: CFIRE Administrative Contact: Jason Bittner Sponsor: CFIRE WisDOT Technical Contact: Approved Starting Date: 7/1/2008 Approved by COR/Steering Committee: $16,493 Approved Ending Date: 6/30/2009 Project Investigator (agency & contact): Mike Oliva, UW-Madison Description: Total study budget Expenditures for current quarter Total Expenditures to date Percent Complete $16,493 0 $15,362 90% Progress This Quarter: April Many of the bridges being load rated and of concern to the Great Lakes Timber Association are older and were not originally designed for the current HL-93 design vehicle. In order to become more familiar with the design vehicles used for the design of several of these bridges, research on the history of the design vehicles was completed. The earliest design vehicle information found dated back to the 1924 ASCE Specifications for Steel Bridges. A time line of the history of the design vehicles was also made to help visualize what trucks were used during a given time period. Figure 1: Timeline of the History of Bridge Design Vehicles

2 Up until this point, all the design truck comparison were done using un-factored loads. As a check, the design vehicles were also compared using factored loads. The figure below shows the moment comparison of the HS20 and the HL93 factored live loads. Figure 2: Comparison of Factored HS20 vs. HL93 In addition to the load rating and logging truck analysis, research on economical options for strengthening bridges is also being done. The use of MF-FRP strips to strengthen bridges is the primary option being looked into. Bridge B has been chosen as a candidate for strengthening using this method. B is a concrete t-beam bridge located in Wausaukee, WI on US-141 and is a major artery for the timber industry. Additionally, an abstract for the Western Bridge Engineer s seminar on using MF-FRP strips for bridge strengthening was also submitted and accepted. This presentation will focus on previous research of this technique done at UW-Madison as well as the work being done to increase the capacity of B In order to better understand the effects of load posted bridges on the timber industry, estimates of the economic impact were obtained from two sources. The following table summarizes the two estimates provided; one being for a particular mill in Wisconsin and the other is an estimate for the State as a whole. Table 1: Estimated Economic Impact of Load Posted Bridges on Forest Products and Processing Industry Raw Timber Produced PCA Mill: Tomahawk, WI ton State Wide 1.6 million cords 3,840,000 tons Extra Haul Route due to Bridge Posting 10 miles miles Amount of Timber 30% 75% Effected by Postings (conservative) Haul Rate $.086/mile/ton $0.095/mile/ton Total Cost (10 mile detour) $451,500 $1,094, Lastly, it was noticed that the condition of the bridge used in load rating is based solely on the National Bridge Inventory (NBI) Ratings. These NBI Ratings were researched and it was determined that the rating are subjective

3 and based on a 1-9 rating scale. Guidelines for inspectors who are determining this rating are found in the Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation s Bridges. May/ May 6: Meeting with Great Lakes Timber Association (Henry Schienebeck, Mike Kretz, Gunnar Bergersen). In this meeting, a presentation showing an overview of all the research results was given and the strengthening of bridge B was discussed. The bridge being considered for strengthening, B is a complex bridge with girders of different dimensions. Because of this, a model is necessary to determine the distribution factors as well as determining which beam will control. As an independent study, an undergraduate student worked to make a SAP model of the irregular concrete t-beam bridge located in Wausaukee, WI. Currently, we are in the process of working out some of the issues of this model. One of the main focuses in May and was working on drafting my thesis for this research. A final outline was reviewed and I have been working on the following sections: logging truck analysis and logging truck optimization. In addition to writing, the final load rating was completed for two bridges. One bridge was a two span steel grider bridge, B and the other was a single span steel girder bridge, B The bridges were load rated using the LFR and LRFR ratings. Only the LFR ratings could be compared to the current WisDOT inspection reports. The results from the two span bridge matched up closely with the WisDOT recorded ratings however the single span bridge, B yielded much higher ratings. Contact with the DOT has been made to discuss these discrepancies. Lastly, a detailed timeline has been made which lays out the plan for completing this research project. This timeline is attached. Work Next Quarter: 1. Complete Load Rating: five more bridges need to be load rating using the final templates. All bridges will be load rated using the LFR and LRFR methods. 2. Work is still being done to get a confidently working model of the candidate bridge for strengthening. Based on the model, the current strength will be determined. Next, the design for the strengthening using MF-FRP strips will be completed for B and additionally the logistics of strengthening the bridge will be addressed. 3. Complete Thesis/Oral Defense Circumstances affecting progress/budget:

4 Gantt Chart: Project Timeline for Summer 2009 Load Rating 12- Jun B B B B B Modeling/Strengthening Create SAP model of the bridge Load Rate 3 beams in the Bridge Strengthening Design/Plan Literature Review Missouri Papers on MF-FRP Bridge Strengthening Wisconsin Resolution for 98,000lb. Load increase Wisconsin Truck and Weight Study Thesis Abstract Introduction Problem Statement Problem Objectives Statement of Scope Probject Background (MnDOT study, WisDOT study) Comparison of Individual Logging Vehicles Comparison of WisDOT Proposed Vehicles Summary of Logging Truck Analysis Bridges of Concern Load Rating of Bridges Intro LR Terms and Definitions LFR Method LRFR Method

5 Project Timeline for Summer 2009 Comparison of LFR vs. LRFR Load Rating Methodology Templates Load Rating Results Summary of Bridge Load Rating Strengthening/Rehabilitation Lit Review (Strengthening) Implementation of Strengthening Strengthening Conclusions Summary, Conclusions and Recommendations Import References from Refworks Submitt Full Draft to Prof. Oliva Defense Presentation Thesis Revisions Present Oral Defense 12- Jun Planned to be done Completed