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Full-Text Articles in Engineering

Evaluation And Development Of Cpt Based Pile Design In Nebraska Soils, Alex Silvey Aug 2018

Evaluation And Development Of Cpt Based Pile Design In Nebraska Soils, Alex Silvey

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Cone penetration testing (CPT) is a well established geotechnical subsurface investigation technique commonly used for site characterization and soil classification. The CPT gives real time end resistance, side friction, and pore pressure readings. Axially loaded piles also share these two resistance mechanisms, suggesting the cone can be considered similar to a miniature pile. This study focused on evaluating eight CPT methods prediction of pile bearing capacity. The Nebraska Department of Roads (NDOR) conducts dynamic load tests (PDA) of driven pile to verify pile capacity for bridge foundations. 91 comparisons of CPT logs and PDA data were evaluated. CPT prediction methods …


Road Diet Feasibility Analysis For Nebraska, Brandon L. Purintun May 2018

Road Diet Feasibility Analysis For Nebraska, Brandon L. Purintun

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Many rural towns and cities throughout Nebraska have experienced consistent population decline over the past 50 years, and the highway system once built to accommodate hoped-for growth is not serving the population as well as it could. These towns and cities would benefit from implementing a road diet conversion on their main highways. Within rural communities, road diets are an increasingly popular method of improving safety along major arterials through the reduction of excess capacity in favor of increasing refuge areas for turning vehicles. A typical application might be the restriping of a four-lane undivided highway into a three-lane highway …


Wetland Conservation Effects Result In Enhanced Playa Functionality In The Rainwater Basin, Nebraska, Hong Zhang Apr 2018

Wetland Conservation Effects Result In Enhanced Playa Functionality In The Rainwater Basin, Nebraska, Hong Zhang

Community and Regional Planning Program: Theses and Student Projects

This study assessed the functionality level of wetland hydrology, hydrophyte and soil conditions, and then identified the restorable potential of conserved playas. The distribution of hydrology and hydrophyte were geospatially examined through annual tracking the quantity and quality of wetlands on historical hydric soil footprints under different conservation programs in the Rainwater Basin (RWB) in Nebraska, USA during 2004-2015. The results show that the historical hydric soil footprints with the conservation programs had significantly higher functionality of ponded water and hydrophyte than non-conserved wetlands. The yearly average of ponded water areas within footprints varies at 12.59% for the Waterfowl Production …


The Long Term Effect Of Agricultural, Vadose Zone And Climatic Factors On Nitrate Contamination In Nebraska’S Groundwater System, Pongpun Juntakut, Daniel D. Snow, Erin M.K. Haacker, Chittaranjan Ray Jan 2018

The Long Term Effect Of Agricultural, Vadose Zone And Climatic Factors On Nitrate Contamination In Nebraska’S Groundwater System, Pongpun Juntakut, Daniel D. Snow, Erin M.K. Haacker, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

A four-decade dataset (1974–2013) of 107,823 nitrate samples in 25,993 wells from western and eastern parts of Nebraska was used to assess long-term trends of groundwater nitrate concentration and decadal changes in the extent of groundwater nitrate-contaminated areas (NO3-N≥10 mg N/L) over the entire state. Spatial statistics and regressions were used to investigate the relationships between groundwater nitrate concentrations and several potential natural and anthropogenic factors, including soil drainage capacities, vadose zone characteristics, crop production areas, and irrigation systems. The results of this study show that there is no statistically significant trend in groundwater nitrate concentrations …