Browsing by Author "Subramaniam, V K"

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    Characteristics of Erosion Control Measures and Their Impact on Erosion
    (2002-06-01) Singh, Udai; Thompson, Anita; Wilson, Bruce N.; Nguyen, Hung; Subramaniam, V K
    This project endeavored to expand experimental data on erosion control blankets and develop greater understanding of how blankets and erosion principles interact. Blankets that are effective in reducing raindrop impact may become ineffective in controlling soil detachment and runoff (rill erosion) on longer slopes. This field study of erosion control products under artificial rainfall conditions was conducted at the Highway 10 overpass in Coon Rapids, Minnesota. Examining long slope lengths (60 feet and 100 feet), bare soil erosion was compared to erosion under straw blankets, wood fiber blankets, straw mulch, and sprayed emulsion. Measurements of runoff, erosion, and biomass (vegetative growth) were made in spring and fall under wet and dry conditions. Sediment loads for bare soil were 8 times larger than other treatments. Sediment loads were substantially smaller for the fall runs than the spring runs, largely due to the substantially increased vegetative cover (biomass). Shear stress partitioning for erosion control blankets was evaluated using a laboratory flume and hot-film anemometry. Erosion control blankets partition shear stress into form shear (the portion that acts on the blanket) and particle shear (the portion that acts on the soil particles). Blanket type, flow conditions, and fastener impacts were considered. Shear partitioning was found to be an important process in design and erosion modeling. Attempts were made to correlate sediment load and vegetative density data gathered by Texas Department of Transportation (TxDOT) with manufacturer's information on blanket characteristics. However, the data from manufacturers was insufficient to determine patterns or predict performance. Keywords-erosion control products, vegetation establishment, soil erosion, slope hydrology
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    Employment of the Traffic Management Laboratory (TRAMLAB) for Evaluating Ramp Control Strategies in the Twin Cities
    (2002-06-01) Michalopoulos, Panos; Hourdakis, John; Muralidhar, K A; Sekhar, A; Subramaniam, V K
    Ramp metering is one way to address freeway traffic congestion. This study employs the Traffic Management Laboratory (TRAMLAB) to evaluate the effectiveness of Mn/DOT's control strategy in three Twin Cities freeway sections totaling approximately 65 miles. It develops a new traffic management concept for early detection of incident-prone traffic conditions and integrates it in order to smooth flow and prevent incident occurrence, thereby further reducing delays and improving safety. The project is part of a larger program which aims to develop the TRAMLAB as part of the ITS Laboratory at the University of Minnesota. Such an environment will contain state-of-the-art traffic simulation programs and allow the development of viable, intelligent, and automated traffic-flow simulation programs and simulation systems that can function as both operational and research tools. Keywords-traffic simulation, traffic control, corridor control, ramp metering, accident prevention, machine, vision detector, freeway
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    Employment of the Traffic Management Laboratory (TRAMLAB) for Evaluating Ramp Control Strategies in the Twin Cities - Summary
    (2002-06-01) Michalopoulos, Panos; Hourdakis, John; Muralidhar, K A; Sekhar, A; Subramaniam, V K
    As freeway traffic congestion spreads ramp metering is implemented to address the problem. However, recently there is increasing opposition to freeway ramp control caused by excessive ramp delays. The objective of this research is to employ a recently developed tool called Traffic Management Laboratory (TRAMLAB) for assessing the effectiveness of Mn/DOT's control strategy in three Twin Cities freeway sections totaling approximately 65 miles. The feasibility of a corridor simulation will be followed by the selection and preliminary model development of the combination of an arterial and a freeway in the Twin Cities. As a result of this testing, TRAMLAB will evolve into an effective tool for developing control strategies that could reduce ramp delays without excessively increasing freeway congestion. Finally, a new traffic management concept for early detection of incident prone traffic conditions will be developed and integrated to traffic management through Ramp Metering and Variable Message Signs in order to smooth flow and prevent (to the extend possible) incident occurrence, thereby further reducing delays and improving safety. Even though this proposal focuses on evaluating ramp metering and implementing a concept recently developed in a current project, we also address the more general issue of research continuity and suggest a strategic partnership with MnDOT. Keywords-Traffic Simulation, Traffic Control, Corridor Control, Ramp Metering, Accident Prevention, Machine, Vision Detector, Freeway