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Mid-America Transportation Center

NDOR Steel Box System (Monitoring of N-2 over I-80 Bridge)

Final Report
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Researchers

  • Principal Investigator: Atorod Azizinamini (aazizinamini1@unl.edu 402-472-5106)
  • Project Status
    Complete
    Sponsors & Partners
  • Nebraska Department of Roads
  • About this Project
    Brief Project Description & Background
    Research performed at the University of Nebraska under the Nebraska Department of Roads (NDOR) project SPRL-PL-1(035) P515 identified an innovative construction detail for use in steel girder bridges. This detail is similar to that used with precast girders where the girders are constructed as simply supported for dead load and made continuous for live load. The N-2 over I-80 Bridge will be the first bridge in the United States to be constructed utilizing this detail. The N-2 over I-80 Bridge is a three steel box system. By using High Performance steel and reducing the weight, the length of each box is extended to 139 ft. This is longer than the traditional 120 ft. usually used for plate or steel box girders. The many new features that have been incorporated in the N-2 over I-80 Bridge, demands that its behavior be monitored. While a good deal of experimental data was collected in the laboratory during previous research projects there is no information from a system subjected to field conditions.
    Research Objective
    The objective is to gain more insight as to actual behavior of the system versus that assumed in the design process and modify the current design provisions if needed, in order to prevent future problems. This will help develop information that could be used to verify and modify the current design procedures if it is deemed necessary.
    Potential Benefits
    NDOR envisions the use of this highly economical system in the future on a more routine basis. Therefore, it is essential to monitor the first bridge constructed using such system and learn from its performance to maximize the performance of other steel box bridges.
    Abstract
    Research performed at the University of Nebraska under the Nebraska Department of Roads (NDOR) project SPRL-PL-1(035) P515 identified an innovative construction detail for use in steel girder bridges. This detail is similar to that used with precast girders where the girders are constructed as simply supported for dead load and made continuous for live load. The N-2 over I-80 Bridge will be the first bridge in the United States to be constructed utilizing this detail. The N-2 over I-80 Bridge is a three steel box system which incorporates following innovations: (1) Steel boxes will be constructed such that they will behave simple for dead loads and continuous for live loads; (2) Steel boxes are connected over the pier using a detail; (3) The bottom flanges of the steel boxes uses constant thickness over the entire length of the span; (4) Only two of the boxes will be provided with inspection holes; (5) The total weight of each of the steel boxes is reduced by using High Performance Steel having a yield strength of 70 ksi; and (6) By using High Performance steel and reducing the weight, the length of each box is extended to 139 ft. This is longer than the traditional 120 ft. usually used for plate or steel box girders. The many new features that have been incorporated in the N-2 over I-80 Bridge, demands that its behavior be monitored. While a good deal of experimental data was collected in the laboratory during previous research projects there is no information from a system subjected to field conditions. The objective is to gain more insight as to actual behavior of the system versus that assumed in the design process and modify the current design provisions if needed, in order to prevent future problems. The main objective of this proposal is to develop information that could be used to verify and modify the current design procedures if it is deemed necessary. NDOR envisions the use of this system in the future on a more routine basis. Therefore, it is essential to monitor the first bridge constructed using such system and learn from its performance.
    Project Amount
    $ 292,244