Railroad Bridge Engineering Challenges Villanova University College of Engineering December 2, 2009

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1 Railroad Bridge Engineering Challenges Villanova University College of Engineering December 2, 2009 Office of Vice President/Chief Engineer

2 Keys to a successful railroad bridge engineering maintenance program Know your infrastructure intimately Carefully manage a bridge inspection program that utilizes trained inspectors Engage experts to analyze critical issues Employ technology to enhance knowledge and to confirm field inspection observations Develop plans/procedures that minimize the impact to railroad operations Be prepared and equipped to respond to events that cause damage to bridges 1

3 Chemical Coast Secondary Br. # Tremley, NJ Built

4 Vineland Secondary Br. #12.22 Wenonah, NJ Built

5 Lehigh Line Br. #11.44 Newark, NJ Built

6 Lehigh Line Br. #11.44 Newark, NJ Built

7 Delair Branch Br. # Delair, NJ Built

8 Delair Branch Br. # Delair, NJ Built 1896 Remove steel to determine steel yield strength Steel coupons for finite element analysis 7

9 Penns Grove Secondary Br. #13.70 Paulsboro, NJ Built

10 Penns Grove Secondary Br. #13.70 Paulsboro, NJ Built

11 Penns Grove Secondary Br. #13.70 Paulsboro, NJ Built

12 Penns Grove Secondary Br. #13.70 Paulsboro, NJ Built

13 Railroads utilize AREMA standards for recommended practices for the design, construction, and maintenance of railway infrastructure in the United States and Canada AREMA and its predecessor associations were formed over 100 years ago when there were 40 Class 1 railroads in the United States The association is comprised of engineers and suppliers with the common purpose of standardizing design and maintenance practices in the industry AREMA has 28 technical committees organized into six groups o Structures o Passenger and Transit o Track o Engineering services o Communication & Signal o Maintenance 12

14 Railroads utilize AREMA standards for recommended practices for the design, construction, and maintenance of railway infrastructure in the United States and Canada The structure group categories include o Building and support facilities o Timber structures o Concrete structures and foundations o Seismic design for railway structures o Structures, maintenance and construction o Steel structures o Clearances The basis for engineering design of many facets within the rail industry is based upon accepted AREMA standards that have been developed and optimized over many years 13

15 The Challenge: Maintaining or increasing bridge weight capacity and extending bridge life Nominal freight car weight has increased from 220,000 lbs. in the 1950 s to the current 286,000 lbs. Engineer s approach to accommodate increasing weight capacity and extending bridge life: Increased/enhanced inspection cycles Reducing speed of train operations to reduce impact Reducing impact on structures by better distribution of loads over structures Increase stiffness by adding bracing and helper stringers Reducing length of spans by adding intermediate bearings or supports Using science and technology; strain gages, finite element analyses to confirm strength of materials Utilization of bridge engineering experts to rate bridge capacity 14

16 In conclusion The majority of bridges and infrastructure that railroads currently operate on were designed for rail cars that were significantly lighter than today s cars This infrastructure has performed very reliably for well over 100 years and can still provide many more years of service if inspected and maintained in a conscientious and reliable manner It is critical to pay attention to the details found during inspections Small maintenance items left unattended will create larger problems over time Engineering experience, a knowledge of railroad operations, and trusting your common sense are the ingredients for a successful bridge maintenance program in the railroad industry 15