McC BarsMcCormick School of Engineering HomeMcCormick School of Engineering HomeNorthwestern University Homepage

Infrastructure Technology Institute

ITI Presents at the 89th Annual Meeting of the Transportation Research Board

The Transportation Research Board (TRB) held its 89th Annual Meeting in Washington, D.C., this past January, with an extensive program that attracted more than 10,000 transportation professionals from around the world. ITI researchers and principal investigators attended the event and presented the results of several projects.

Professor Joseph Schofer reported the outcomes of the recent UTC Spotlight Conference Developing a Research Agenda for Transportation Infrastructure Preservation and Renewal. In November, 2009, the Spotlight Conference drew public and private infrastructure owners and managers together with researchers to discuss infrastructure preservation problems and needs and to define a research agenda for the future. Schofer chaired the planning committee of the spotlight conference, in close collaboration with Thomas Palmerlee, TRB Associate Director of the Technical Activities Division.

Four members of the planning committee reported on the recommended research agenda that was borne out of the 2009 conference, and senior managers from the California Department of Transportation and the Massachusetts Bay Transportation Authority commented on the relationships between the recommendations and their agency needs. This is the beginning of a larger effort to advance the research agenda by disseminating it widely to a variety of audiences.

Also at the TRB meeting, Professor Pablo Durango-Cohen gave a tutorial on application of time-series methods to infrastructure deterioration data in an all-day workshop on statistical methods in transportation research. These methods filter through a data set that may contain many daily, seasonal, or annual cycle elements. Because of the number of factors in the data, relevant trends are often obscured. Advanced statistical tools make it possible to smooth out these external factors to reveal an underlying trend. It is then possible to create a deterioration model that will be useful for management decision-making.

Durango-Cohen presented several case studies of time-series analysis for infrastructure data, including analysis of the 1958-1960 AASHO road test and deterioration of a highway bridge element monitored by ITI. The AASHO road test was a comprehensive full-scale accelerated test of flexible and rigid pavements under a variety of designs and loadings. Since pavement performance is affected by seasonal changes, Durango-Cohen uses statistical tools to find the true deterioration trend within the seasonal elements of the data set. In the case of the bridge element, a bolt which fractured under repeated loading and corrosion damage, Durango-Cohen is searching for a trend in the data recorded before fracture that could provide early warning of future failures.

Research engineer David Kosnik presented a paper entitled “Autonomous Condition Monitoring of an In-Service Historic Utility Tunnel.” This paper discussed a unique monitoring project in which ITI instrumented a section of century-old freight tunnels in downtown Chicago. These tunnels once connected many of the buildings in Chicago’s central business district for freight delivery and refuse collection but now carry electrical and communication cables throughout the area, including to financial markets. The presence of these critical utilities in the tunnels immediately adjacent to a deep excavation for a new building prompted the Chicago Department of Transportation (CDOT), which is the organization responsible for oversight of the tunnels, to enlist the help of several organizations, including ITI, to install sensor systems to monitor the effects of the excavation on the tunnels.

ITI engineers installed a network of displacement sensors at fourteen locations along the city block-long length of tunnel adjacent to the excavation. A field computer with custom software written at ITI recorded sensor data hourly and automatically uploaded it nightly to ITI servers, where it was published on a password-protected web site for review and analysis by CDOT and others. CDOT personnel brought the latest data from the web site to daily construction meetings at which they had authority to halt work if excessive displacements were measured. The ITI monitoring system operated continuously for over two years, by which time the excavation was complete. Ultimately, little movement was measured at the tested locations; nonetheless, all parties benefited from the near real-time availability of displacement data from ITI’s sensing network in the tunnel throughout the project.