Design Considerations for Embankment Protection During Road Overtopping Events

This report describes the research conducted by the University of Minnesota and project partners on roadway embankment overtopping by flood water. Roadway overtopping is a major safety concern for Minnesota transportation managers because of the potential for rapid soil erosion and mass wasting resulting in partial or complete failure of the roadway embankment. This multi-year research study focused on various aspects of the roadway embankment overtopping. A robust literature survey was performed to identify research, reports and other published knowledge that would inform the project. A field- based research campaign was developed with the goal of collecting data on the hydraulics associated with full-scale overtopping events. Finally, a series of laboratory experiments were conducted at the St. Anthony Falls Laboratory, University of Minnesota to study the hydraulic and erosional processes associated with embankment overtopping and in particular study of three slope protection techniques under overtopping flow. The largest component of the research project was the laboratory hydraulic testing, which focused on bare soil (base case) and three slope protection technologies. A full- scale laboratory facility was constructed to carry out the testing. Three erosion protection techniques were examined including 1) armored sod, 2) turf reinforcement mat, and 3) flexible concrete geogrid mat. Overtopping depths of up to 1-ft were used to determine the failure point of the protection technique and soil on both the 4h:1V and 6V:1H slopes. The full project report details the testing of each protection technique as well as observations and findings made during the testing

A Theoretical Framework for Interpreting and Quantifying the Sampling Time Dependence of Gravel Bedload Transport Rates

1 online resource (PDF, 23 pages, includes illustrations)Fienberg, Kurt; Singh, Arvind; Foufoula-Georgiou, Efi; Jerolmack, Doug; Marr, Jeffrey D.G.. (2009). A Theoretical Framework for Interpreting and Quantifying the Sampling Time Dependence of Gravel Bedload Transport Rates. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/180094

StreamLab Collaboratory: Experiments, Data Sets, and Research Synthesis

A series of community-led, large-scale laboratory experiments, termed “StreamLab”, were performed by the National Center for Earth-surface Dynamics (NCED) with the purpose of advancing multidisciplinary research, education, and knowledge transfer at the interface of physical/chemical/biological processes in streams, science-based stream restoration practice, and environmental sensing technologies. Two series of experiments, StreamLab06 and StreamLab08, were conducted in the Main Channel of the St. Anthony Falls Laboratory at the University of Minnesota, a flume 84 m long and 2.75 m wide with water fed by the Mississippi River at a rate of up to 8.5 m3/s. The purpose of this paper is to share with the broader community the data collected with the hope of stimulating further analysis and future experimental campaigns toward advancing our predictive understanding of the physical, chemical, and biological processes in streams. Toward this end, a brief summary of the results to date is included and some ideas for further research are provided

Design Considerations for Embankment Project During Road Overtopping Events

Minnesota Department of Transportatio

A Research Plan and Factors Affecting Service Life for Culvert Pipe Materials in Minnesota

Minnesota Department of Transportatio

The Need for Full-Scale Experiments in River Science

Studying river processes in the laboratory offers important advantages, particularly the opportunity for precise experimental control and the ability to isolate specific processes. There is, however, a key trade-off. To control essential variables and support tractable technical measurements, experiments are typically conducted at a reduced scale, which introduces a potential loss of realism. The methods and limitations of scale modeling are well developed in some aspects of river science (such as hydraulics and sediment transport) and are emerging in others (such as biogeochemical transport and flow/organism interactions)

Desmopressin for nocturnal enuresis in nephrogenic diabetes insipidus.

Item does not contain fulltextWe have investigated two unrelated families, in which two children had inherited primary nocturnal enuresis, and nephrogenic diabetes insipidus caused by new mutations in the aquaporin-2 gene (AQP2). The mutant AQP2 proteins were inactive, suggesting that administration of desmopressin could not concentrate the urine in these patients. However, treatment with desmopressin resolved primary nocturnal enuresis completely. This observation questions the notion that desmopressin resolves primary nocturnal enuresis through pharmacological manipulation of renal concentrating ability only. Desmopressin might also act on extrarenal targets such as the central nervous system. Muller, Domini

Physical Model Study of Marmot Dam Removal: Cofferdam Notch Location and Resulting Fluvial Responses

This report summarizes observations made for a set of experiments conducted using the physical model of the Sandy River and Marmot Dam constructed for Portland General Electric (PGE). The experiments focused on the location of the cofferdam notch and its impact on the immediate sediment remobilization, knickpoint location and trajectory, volume of removal, and location of stranded sediment. The motivation for the study was to provide insights on how and if the position of a cofferdam notch will have an impact on how the site fails and how the reservoir sediments are remobilized. Based on early experiments with the model, PGE expressed concern that some failure scenarios resulted in abandonment of large terraces of sediment near the dam site, posing potential public safety issues. One goal of these experiments was to determine if cofferdam notch location could be positioned to minimize the volume of sediment stranded in terraces. Eight model scenarios were completed for this study. Seven of the scenarios examined a failure discharge of 2500 cfs (cubic feet per second), the minimum failure design discharge. Within these seven scenarios, we examined three notch positions; river right (north bank of river), center, and river left (south bank of river). In an eighth scenario we examined a river right notch location and failure at a high discharge of 5500 cfs. Sediment mixtures used in the model were scaled to sediment core data of the Sandy River reservoir sediment. The data and observations indicate that at the minimum design failure discharge of 2500 cfs, notch position does impact the location of cofferdam failure as well as the location of the first major knickpoint and its trajectory. The data suggest that a river left notch position minimizes the extent of stranded sediment terraces and a river right notch tends to result in larger terraces. A center notch position yielded similar results to the river right notch. At a discharge of 5500 cfs, results suggest that notch position is less important than at lower discharge rates, as the knickpoint is more or less bank to bank and is able to mobilize sediment more effectively.Portland General ElectricMarr, Jeffrey D.G.; Hill, Craig; Johnson, Sara; Grant, Gordon; Campbell, Karen; Mohseni, Omid. (2007). Physical Model Study of Marmot Dam Removal: Cofferdam Notch Location and Resulting Fluvial Responses. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/109967