Browsing by Subject "Service life"

Now showing 1 - 4 of 4
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    A Qualitative and Quantitative Assessment of Pavement Sections that have Remained in Poor Condition for 5-Plus Years
    (Minnesota Department of Transportation, 2021-06) Calhoon, Thomas; Marasteanu, Mihai
    The 2014 Transportation Asset Management Plan calls for developing a method to annually track, monitor, and identify road segments that have been in poor condition for more than 5 years and consistently consider them when programming. In Minnesota, pavements are considered in poor condition when the ride quality index (RQI) is less than or equal to 2.0. There are still pavement segments that have remained in poor condition for more than 5 years. However, it is not clear if RQI and RSL metrics accurately quantify the "true" condition of the system. In this study, the roadway segments that have maintained a poor ride quality index over time were identified in each district and extensive additional information was obtained from interviews with district engineers and planners. The analysis of the additional information shows that most pavement sections that have remained in poor condition for extended periods are actually not in poor condition. They represent “anomalies” with unique characteristics, and new parameters must be established to quantify the true condition of these sections.
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    Remaining Service Life Asset Measure, Phase 1
    (Minnesota Department of Transportation, 2018-07) Kumar, Ravi; Matias de Oliveira, Jhenyffer; Schultz, Arturo; Marasteanu, Mihai
    There is a critical need to use a common metric, such as a service life parameter, across many different types of infrastructure assets. MnDOT has used the remaining service life (RSL) measure for pavement condition for several years and is starting to use it for bridge condition. In this study, researchers examined what has been done to date and what tools and methodologies are available nationally and internationally, and made recommendations on a future measure that can be used to show the "true" condition of the system. First, a literature review was performed to summarize current methods used in asset management and life-cycle cost analyses. A survey was also performed to collect information from agencies around the country. An assessment of current practice used by MnDOT Bridge Office and Materials and Road Research Office was performed next to identify similarities and differences between the two approaches. Based on the information collected, suggestions for a common method were presented and guidelines for a work plan for a follow-up phase 2 were developed.
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    Remaining Service Life Asset Measure, Phase 2
    (Minnesota Department of Transportation, 2022-02) Matias de Oliveira, Jhenyffer; Khani, Alireza; Davis, Gary; Marasteanu, Mihai
    The main objectives of phase 2 of this project were to obtain relevant data to calculate the percent remaining service life interval (PRSI) and two additional metrics and to perform Markov chain analysis and dynamic programming to determine how much time and funding is required to bring the system to a stable configuration, which allows for more consistent planning. First, relevant pavement management data was obtained from MnDOT and preliminary data analyses were performed. The prediction models and optimization process currently used by MnDOT were investigated and summarized. Next, two additional metrics, Asset Sustainability Ratio and Deferred Preservation Liability, were calculated for MnDOT’s network. Then details of the estimation process of state-to-state transition probabilities to be used in the Markov chain model were presented. To allow for site-specific variation, ordinal logistic regression models were incorporated in the Markov chain model. The results were used in a dynamic programming optimization methodology to obtain baseline and optimal policies for different scenarios and a user-friendly excel spreadsheet tool was developed. Finally, a summary of the work performed followed by conclusions and recommendations was presented.
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    Understanding and Mitigating the Dynamic Behavior of RICWS and DMS Under Wind Loading
    (Minnesota Department of Transportation, 2020-06) Linderman, Lauren; Guala, Michele; French, Catherine; Schillinger, Dominik; Finley, Nicole; Heisel, Michael; Nguyen, Lam; Stoter, Stein; Vievering, Josh; Zhu, Qiming
    Dynamic Messaging Signs (DMS) and Rural Intersection Conflict Warning Signs (RICWS) are roadside signs that feature much larger and heavier signs than are typically placed on their respective support systems. The excess weight and size of these signs, in conjunction with their breakaway support systems, introduces vibration problems not seen in the past. The AASHTO 2015 LRFD Specification for Structural Supports for Highway Signs, Luminaires, and Traffic Signals (SLTS) does not yet address vibration design for these nontraditional roadside signs. DMS and RICWS were instrumented in the field and numerically modeled to explore their wind-induced behavior. A dynamic numerical model was validated with experimental field data and used to evaluate the fatigue life of the DMS support system instrumented in the field. The resulting fatigue life differed significantly from the equivalent static pressure analysis prescribed in the AASHTO specification. The fatigue life of the DMS instrumented in the field was conservatively estimated to be 23.8 years. Based on data collected from a RICWS instrumented in the field and experiments done on a scaled model of the RICWS at the St. Anthony Falls Laboratory, vortex shedding was identified as the predominant wind phenomena acting on the RICWS structure. Three modifications were proposed to reduce the impacts of vortex shedding. The investigation of these newer sign types highlights the importance of considering the impact of dynamic behavior and vortex shedding on the structural design.