Engineering Commons^™

Experimental Study On A New Type Of Transverse Connection For Nebraska County Bridge System, Alexander Bleyhl

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

Many county-owned bridges in Nebraska need replacement due to their structural deficiency. Most of the bridges needing replacement are in the 40 to 60 ft range. This span range lacks a standard design that fits Nebraska county practices in terms of speed and simplicity of construction. The current systems being used are (a) Precast 1 by 2 ft planks which can span up to 30 ft, (b) Cast-in-place slab bridges which can span up to 50 ft but require extensive field formwork, concrete placing, and curing, and are best when constructed in three-span units, and (c) Inverted tees which can …

Investigation Of A Tractor-Tank Trailer Roadside Containment Barrier, Dean L. Whitfield

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

The objective of this research project was to develop a new, cost-effective, Manual for Assessing Safety Hardware (MASH) Test Level 6 (TL-6) barrier. A literature review on prior Test Level 5 and Test Level 6 barriers was conducted, and the cost of current TL-5 and TL-6 barriers was established. Existing and modified design procedures for roadside barrier were reviewed as well as current TL-6 design forces. A preliminary TL-6 truck model was developed in LS-DYNA. The minimum barrier height to contain a tractor-tank vehicle was determined to be 62 in. for a rigid, vertical-faced barrier through LS-DYNA computer simulation. New …

Effects Of Moving Bottlenecks On Traffic Operations On Four-Lane Level Freeway Segments, Jianan Zhou

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

The Highway Capacity Manual (HCM) was developed to provide capacity and level of service analyses for roadway facilities. Trucks may adversely affect the quality of traffic flow on a roadway. In HCM, the passenger car equivalent (PCE) of a truck, which represents the number of passenger cars that have an equivalent effect on traffic flow, is used to account for the impacts of trucks. However, in the past ten years rural freeways in the western rural U.S. have experienced conditions that lie outside the standard HCM conditions. Also, the current HCM truck PCEs may not be appropriate for the western …

Effect Of Swine Manure Pit Additives And Facility Disinfectants On The Fate Of Antibiotics And Manure Composition During Simulated Swine Manure Slurry Storage, Jon Duerschner

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

This thesis investigates the effect of time and of swine manure slurry treatment on the physical properties, nutrient content, and the concentrations of antibiotics chlortetracycline, lincomycin, and tiamulin in simulated storage of swine manure. In one experiment the slurry was treated with six additive products. In a second experiment a set of four disinfectant products were used. Control consisted of unamended slurry. Manure was stored in 60 liter stainless steel bioreactors to simulate deep pit storage and was sampled 7 times over a 40 day incubation.

From an ANOVA of the results, it was concluded that evaporation may be contributing …

Statistical Investigation Of Road And Railway Hazardous Materials Transportation Safety, Amirfarrokh Iranitalab

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

Transportation of hazardous materials (hazmat) in the United States (U.S.) constituted 22.8% of the total tonnage transported in 2012 with an estimated value of more than 2.3 billion dollars. As such, hazmat transportation is a significant economic activity in the U.S. However, hazmat transportation exposes people and environment to the infrequent but potentially severe consequences of incidents resulting in hazmat release. Trucks and trains carried 63.7% of the hazmat in the U.S. in 2012 and are the major foci of this dissertation. The main research objectives were 1) identification and quantification of the effects of different factors on occurrence and …

Shear Strength Characteristics And Failure Mechanism Of Slopes In Overconsolidated Soils Of Nebraska, Hossein Bahmyari

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

Geotechnical engineers deal with some challenging problems when encountering long-term slope stability in overconsolidated clays and clayey shales. One of these problems is determining a suitable method to estimate the reliable shear strength of overconsolidated clayey soils for long-term slope stability. According to Eversol (2013), one half of the counties in Nebraska have experienced slope failure in overconsolidated soils, especially in north and east Nebraska. In this research, shear strength characteristics of overconsolidated clayey soils of Nebraska is investigated in regard to long-term stability of slopes, and the failure mechanism in such soils is examined.

Undisturbed samples from boring logs …

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 …

Artificial Neural Network And Finite Element Modeling Of Nanoindentation Tests On Silica, Kianoosh Koocheki

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

Two major forms of Silica include the crystalline form named Quartz which consist of the sand grains in nature, and amorphous form named Silica Glass or Fused Silica which is commonly known as glass. Fused Silica is an amorphous crystal that can show plastic behavior at micro-scale despite its brittle behavior in large scales. Due to the amorphous and ductile nature of Fused Silica, this behavior may not be explained well using the traditional dislocation-based mechanism of plasticity for crystalline solids. The crystal plasticity happens due to shear stress and stored energy in the material as dislocations which does not …

Integration Of Remote Sensing And Proximal Sensing For Improvement Of Field Scale Water Management, Foad Foolad

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

Water is one of the most precious natural resources, and sustainable water resources development ‎‎is a significant challenge facing water managers over the coming decades. Accurate estimation of ‎‎the different components of the hydrologic cycle is key for water managers and planners in order ‎‎to achieve sustainable water resources development. The primary goal of this dissertation was to ‎investigate techniques to combine datasets acquired by remote and proximal sensing and in-situ ‎sensors for the improvement of monitoring near surface water fluxes. This dissertation is ‎separated into three site-specific case studies. First study, investigated the feasibility of using ‎inverse vadose zone …

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 …

Optimized Health Monitoring Plans For A Steel, Double-Track Railway Bridge, Ahmed Rageh

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

Railway bridges are an essential component of any modern society and play a significant transportation role. During the 19^th and early 20^th centuries steel truss and plate girder bridges were commonly used railway designs, with most of the trusses constructed using pin and eyebar systems and most other load carrying members being riveted, built-up sections.

Many of these bridges are still in use and are subjected to increased railway traffic intensity, loads and speeds. The current practice for evaluating the integrity of bridges in the United States, irrespective of use, is primarily via visual inspection, with those inspections …

Examination Of Steel Pin And Hanger Assembly Performance – Retrofit To Replacement, Chandana Chickamagalur Balakrishna

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

A number of steel, multi-beam bridges exist in the United States that contain pin and hanger assemblies. Pin and hanger assemblies are fracture critical members whose failure would result in collapse of the bridge or render it unable to perform its expected functions. As these bridges continue to age, many assemblies have deteriorated to a point where retrofit or replacement has to be considered and performed to maintain intended safety and performance. States have taken various approaches to address the pin and hanger assembly retrofit and replacement options. However, there is no single document that summarizes these approaches.

This research …

Finite Element Modeling And Updating Of A Five-Tiered Pagoda Style Temple, Linh Maytham Abdulrahman

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

Historical pagoda style temples demonstrate different dynamic behavior than traditional unreinforced masonry (URM) structures due to the unique construction practices and ornate architectural detailing. Recently, the 2015 Gorkha M_w 7.8 earthquake resulted in widespread structural damage and collapse of similar historic temples in Nepal. However, one temple did not collapse. This is the five-tiered pagoda style Nyatapola temple built in 1702 and located in Bhaktapur, Nepal. Understanding the seismic vulnerability and structural behavior of these pagoda-style temples can lead to more efficient retrofit solutions and conservation practices for similar heritage structures.

This study developed and calibrated the pre- and …

Rainwater Harvesting System Scenario Analysis On Runoff Reduction Potential In Surabaya, Indonesia: A Geospatial Analysis For Brantas Hilir Watershed, Putri Sukmahartati

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

Global warming has become an environmental concern over the past several decades and its impact on the water cycle is very crucial to the well-being of the human population. In the hydrological cycle, water evaporates by the heat of the sun and atmosphere, where it is accumulated in the atmosphere via clouds and it then falls as rain. With warmer temperatures, more intensive evaporation and downpours occur. In addition, impervious surfaces are increasing as a result of urban development. Those surfaces cause more water to flow faster into open water bodies, creating more extensive flooding, and additionally reducing water quality. …

Structural Identification And Assessment Of The Inverted Tee Girder Bridge System, Garrett P. Martindale

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

The Inverted Tee (IT) girder bridge system was originally developed in 1996 by the University of Nebraska–Lincoln (UNL) and Nebraska Department of Roads (NDOR) engineers. This bridge system currently accounts for over 110 bridges in Nebraska used for both state highways and local county roads. Excessive transverse and longitudinal deck cracking has been observed and noted in numerous bridge inspection reports. Since the IT girder bridge system is relatively new, limited data and knowledge exist on its structural performance and behavior. This study evaluates the IT girder bridge system by conducting twenty field observations as well as recording accelerometer time …