by: Matt Mann, Research Program Coordinator
MassDOT continues to monitor, repair and replace its existing transportation infrastructure. Bridges are a key component of the infrastructure and essential for Massachusetts growing economy. Through data collection, bridge inspections, and daily maintenance, MassDOT knows when each bridge will need to be replaced or rehabilitated.
MassDOT performs a regular and semi-regular inspection of their bridge network. Funding for the bridge infrastructure looks at ownership and length of the structure. Collecting bridge attributes and deficiencies allows MassDOT to develop comprehensive of their assets.
Over the past few years, the Accelerated Bridge Program (ABP) has met the challenges to reduce the number of deficient bridges in the Commonwealth. The goal of this Program is to deliver projects quickly and relies on accelerated bridge construction as a means to reduce road closure durations. There are two specific bridge projects that are looking to accommodate demand and technology for the next generation. One is in the implementation phase and the other in the research phase, both shining a light on MassDOT’s commitment to accommodating future transportation demand in the Commonwealth.
MassDOT is undertaking the Longfellow Bridge Rehabilitation Project, one of five major projects of the Commonwealth’s ABP. This historic bridge provides vital transportation connections between Boston and Cambridge. Keeping in-line with the historic character of the bridge, structural deficiencies will be addressed, and multi-modal connections will be improved.
A recently launched MassDOT research project looks more closely at the deterioration of the steel beam ends due to corrosion of leaking bridge joints. Dr. Simos Gerasimidis of UMass Amherst is the Principal Investigator on the project. We asked him to give us some information on the project and the expected outcomes.
“As the Commonwealth’s bridge population ages, MassDOT is witnessing more and more instances of deterioration of the web at steel beams ends due to corrosion as a result of leaking bridge joints. This deterioration reduces the load carrying capacity of beams at a critical point where the beam sits on its bearing. In extreme cases, the web fails and the bridge has to be closed. Therefore, the determination of the remaining load carrying capacity is very important, however, there are no good methods for performing this analysis and so, it has been very difficult to calculate realistic estimates of the remaining capacity of the web. This research aims to first; identify the most common configurations (shapes and locations) of steel beam end deterioration by reviewing detailed inspection reports for various bridges. These patterns will be used to develop advanced computational models for structural analysis and the results of the analysis will be utilized to develop new procedures for determining the safe capacity of deteriorated beam ends that can be incorporated into the MassDOT Bridge Manual.
Secondly, actual steel beams with deteriorated ends will be subjected to full-scale testing at the UMass, Amherst Structural Testing Facility to validate the procedures that are being proposed. Finally, the ultimate goal of the project is to update the current guidelines as they appear in today’s codes.”
Both of these bridge projects will benefit the Commonwealth for years to come. Combining data analysis and maintenance, with innovation and technology, will continue to keep our infrastructure in good shape.