Civil Engineering Commons^™

Effects Of High-Impedance-Contrast Boundary Upon Multi-Modal Seismic Surface Wave Data, Prajwol Tamrakar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Synthetic studies and analyses of an experimental dataset were conducted to address the use of Rayleigh-type surface waves for estimation of shear wave velocity (VS) profiles of shallow bedrock sites. The shallow bedrock presents a high impedance contrast boundary which causes surface wave energy to be partitioned to higher modes. Idealized studies of hypothetical datasets and root-mean-squared calculations of error surfaces showed that if reliable dispersion data are available over a broad frequency spectrum, the VS profile can be recovered using the fundamental mode alone. However, when dispersion data are limited to a relatively narrow frequency band representing what might …

Dimensional Stability Of Geosynthetic Clay Liners In Landfill Applications, Gregory R. Olsen

Master's Theses

An investigation was conducted related to the dimensional stability of geosynthetic clay liners (GCLs) in landfill applications. Multiple occurrences of panel separation of overlap seams in GCLs have been documented; however, explanation for the relative contribution of various mechanisms causing shrinkage has been limited. A systematic test program was conducted to determine the effects of a variety of conditions on GCL dimensional stability.

Effects of initial moisture content, permeant type, and overburden pressure were tested by subjecting various GCL products to wet-dry cycles and measuring the dimensional change with each cycle. Different GCL types were each tested under various combinations …

Seamless Bridge And Roadway System For The U.S. Practice, Nima Ala

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

Expansion joints are one of the main causes for high maintenance costs in bridges. The search for ideal expansion joints has proven fruitless. That is why it has been said that “the best joint is no joint”. A seamless bridge system is envisioned that results in bridges with long service lives by eliminating the joints over the entire length of the bridge, approach slab and a segment of the roadway called transition. All bridge thermal movements are dissipated to zero in the transition. The system is similar to a system developed in Australia but modifications had to be made to …

Development Of A High Strain-Rate Constitutive Model For Sands And Its Application In Finite Element Analysis Of Tunnels Subjected To Blast, William T. Higgins Iv

Master's Theses

This thesis describes the development of a constitutive model for simulating the high strain-rate behavior of sands and demonstrates the use of the model by analyzing underground tunnels subjected to blast. The constitutive model is based on the concepts of the critical state soil mechanics and bounding surface plasticity theory. The model captures the behavior of sand under multi-axial loading conditions and predicts both drained and undrained behavior at small and large strains. Perzyna’s overstress theory is incorporated in the model to simulate the viscoplastic behavior of sand under high strain rate. The model follows a nonassociated flow rule.

The …

Constitutive Model For Rate Dependent Behavior Of Clay Internal Geotechnical Report 2011-3, Harry Martindale, Dipanjan Basu

Technical Reports

This report presents a strain-rate dependent plastic constitutive model for clays. Based on the concepts of critical-state soil mechanics and bounding surface plasticity theory, the model reproduces the mechanical response of clays under multi-axial loading conditions and predicts both the drained and undrained behavior. The model parameters are determined for Boston Blue Clay, London Clay and Kaolin Clay, and the performance of the model in simulating the mechanical response of these clays is demonstrated for low to medium strain rates. The sensitivity of each model parameter is checked by perturbing the calibrated values by ±20%. Subsequently, a probabilistic analysis using …

A High Strain-Rate Constitutive Model For Sand With Application In Finite Element Analysis Internal Geotechnical Report 2011-4, William Higgins, Dipanjan Basu

Technical Reports

The report presents a constitutive model for simulating the high strain-rate behavior of sands. Based on the concepts of critical-state soil mechanics, the bounding surface plasticity theory and the overstress theory of viscoplasticity, the constitutive model simulates the high strain-rate behavior of sands under uniaxial, triaxial and multiaxial loading conditions. The model parameters are determined for Ottawa and Fontainebleau sands, and the performance of the model under extreme transient loading conditions is demonstrated through simulations of split Hopkinson pressure bar tests up to a strain rate of 2000/sec. The constitutive model is implemented in a finite element analysis software to …

Fourier Finite Element Analysis Of Laterally Loaded Piles In Elastic Media Internal Geotechnical Report 2011-1, William Higgins, Dipanjan Basu

Technical Reports

Laterally loaded piles are analyzed using the Fourier finite element method. Pile response was observed to be a function of the relative stiffness of pile and soil and of the pile slenderness ratio. The analysis is mostly performed for piles embedded in elastic soil with constant and linearly varying modulus although the pile response in two-layer soil profiles is also investigated. Equations describing pile head deflection, rotation and maximum bending moment are proposed for flexible long piles and stubby rigid piles. The design equations were developed after plotting the pile responses as functions of pile-soil stiffness ratio and pile slenderness …

Sustainability In Geotechnical Engineering Internal Geotechnical Report 2011-2, Aditi Misra, Dipanjan Basu

Technical Reports

The built environment serves as a dynamic interface through which the human society and the ecosystem interact and influence each other. Understanding this interdependence is key to understanding sustainability as it applies to civil engineering. There is a growing consensus that delivering a sustainable built environment starts with incorporating sustainability thoughts at the planning and design stages of a project. Geotechnical engineering is the most resource intensive of all the civil engineering disciplines and can significantly influence the sustainability of infrastructure development because of its early position in the construction process. In this report, a review is made of the …

Rate-Dependent Behavior Of Clay, Harry F. Martindale Iv

Master's Theses

This thesis presents a strain-rate dependent two-surface plasticity constitutive model for clays based on the critical-state soil mechanics.  The model reproduces the mechanical response of clays under multi-axial loading conditions and predicts both drained and undrained behaviors at small and large strains.  Model parameter values are determined for Boston Blue Clay, London Clay and Kaolin Clay.  The performance of the model in simulating the mechanical response of clays is demonstrated for a variety of strain rates. Sensitivity of each model parameter is checked for ±5, ±10 and ±20% of the deterministic values. Probabilistic analysis using Monte Carlo simulations were done …

Complex Vs Profiles To 100 M Depth From Rayleigh Waves And 3-D Vs Model For Las Vegas Valley, Helena Murvosh

UNLV Theses, Dissertations, Professional Papers, and Capstones

A three-dimensional (3-D) shear wave velocity (VS) model was developed for the heterogeneous shallow sediments (to nearly 400 m) of the Las Vegas Valley (LVV), Nevada. The model was based on more than 200 VS profiles and 1400 geologic well logs. Five sediment units including a cemented unit were defined from geologic log descriptions. A characteristic VS profile for four of the units was obtained by correlating between closely spaced pairs of VS and sediment data; a constant VS was assigned to the cemented unit. VS profiles were then assigned to each well location based on type of sediment according …

Influence Of Nozzle Pressure, Standoff Distance, And Reinforcing Steel Cage On Water Jetting Of Cidh Pile Anomalies, Matthew Jason Schaffer

Master's Theses

The effectiveness of removing anomalous material from cast-in-drilled-hole (CIDH) piles by water jetting was examined.  The primary objectives of this research were to examine how reinforcing steel influences water jetting and to evaluate how jetting pressures and standoff distance from the material surface affect water jetting of concrete type materials and PVC tubing.  The experimental work consisted of water blasting submerged test specimens using rotary jets, nozzles, pumping equipment, and testing procedures currently used in construction practice.  The concrete test specimens were comprised of ring- and cylinder-shaped samples, containing materials with compressive strengths of approximately 160 and 3,600 psi.  Typical …

Effects Of Warm-Mix Asphalt Additives On Asphalt Mixture Characteristics And Pavement Performance, Jun Zhang

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

The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera synthetic zeolite) were evaluated. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their HMA counterparts were implemented in Antelope County, Nebraska. More than one ton of field-mixed loose mixtures were collected at the time of paving and were transported to the NDOR and UNL laboratories to conduct comprehensive laboratory evaluations and pavement performance predictions of the …

An Exploratory Survey Of Drivers’ Knowledge Of Right Of Way At Freeway On-Ramp Merging Areas, Deogratias Eustace, Stephen Owusu-Ansah, Vamsi Krishna Indupuru

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Motor vehicle crashes are one of the leading causes of death in the United States. The most recent data available show that in 2006 there were almost 6 million police-reported motor vehicle crashes in the United States where a total of 42,642 people were killed and an additional 2.6 million were injured. The majority of these motor vehicle crashes occurred at intersections or within the intersection influence areas. Traffic conflicts occur at intersections due to traffic streams moving in different directions interfering with each other, and as a result they become areas with high potential for traffic crashes compared with …

Peat Improvement Under Vacuum Preloading:A Novel Approach For Bog Roads In Ireland, Juan Pablo Osorio, Eric R. Farrell, Brendan C. O'Kelly

Conference papers

This paper presents the preliminary findings of a TCD/NRA vacuum preloading field trial that is part of a research project into the construction options for improving rampart roads. Vacuum preloading is a construction method used to accelerate settlement and the increase shear strength by applying a vacuum pressure to the ground by means of prefabricated vertical drains, an impervious tight sheet and a vacuum pump. Consolidating the ground by applying a vacuum load has several advantages over other techniques, for example; no fill material is required; construction periods are generally shorter; and there is no need for chemical admixtures. This …

A Life Cycle Cost Analysis Of Large-Scale Thermal Energy Storage Technologies For Buildings Using Combined Heat And Power, Kenneth Gaine, Aidan Duffy

Conference Papers

Buildings account for approximately 40% of energy consumption and greenhouse gas (GHG) emissions in developed economies, of which approximately 55% of building energy is used for heating and cooling. The reduction of building-related GHG emissions is a high international policy priority. For this reason and because there are many technical solutions for this, these polices should involve significant improvements in the uptake of small-scale energy efficient (EE) systems. However the widespread deployment of many technologies, must overcome a number of barriers, one of which is a temporal (diurnal or seasonal) mismatch between supply and demand. Costeffective thermal storage solutions have …

A Study Of Cause And Effect Relationships Of Snowmelt-Induced Movement For The Skunk Hollow Landslide, Brent P. Randall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Skunk Hollow Landslide (located 1 mile north of Mantua, UT along US-89) was instrumented with an automated monitoring system to aid in the determination of the triggering mechanism of slow moving landslides. Data was transmitted wirelessly through telecommunications to allow year-round, real-time monitoring of the site. Measurements were recorded and analyzed for the first season of landslide movement (fall 2009 to spring 2010) to better understand the correlations between snowmelt and movement initiation. Based on the first year of data, it appears that the Skunk Hollow Landslide is controlled by water infiltrating into the slide mass through cracks and …

Performance Of A Stormwater Filter And Bacteria Inactivation Using Biocidal Media, Alexander Scott Bowerman

Master's Theses

There are many possible ways to mitigate stormwater pollution, but this study focused on the DrainPacTM catchment basin insert and the feasibility of integrating N-halamine biocidal brominated beads into the filter system. This study was divided into three sections. The first section involved testing a DrainPacTM filter for treatable flow rates, head loss, and removal of solids, oil, and bacteria. The DrainPacTM filter is designed to be installed in a stormwater catch basin. The filter is composed of a 12 x 41 inch metal frame with textile filter media attached to it in a basket shape. The upper portion of …

Impact Of Moisture Content And Density On Stiffness-Based Acceptance Of Geomaterials, Lourdes Guadalupe Pacheco

Open Access Theses & Dissertations

Modulus-based quality management of compacted layers has been considered by a number of highway agencies. Even though simple in concept, the paradigm shift from density to modulus for quality acceptance has generated some technical and institutional challenges. One of these complications is that for a given density, the modulus can vastly vary depending on the moisture content at the time of compaction and at the time of acceptance. The results of a systematic study carried out to qualify and quantify the impact of compaction moisture content, moisture content at the time of field testing and density on the modulus and …

Applicability Of Mepdg For India Based On Texas Pavement And Environmental Conditions, Vamsi Krishna Pinnamaneni

Open Access Theses & Dissertations

The Indian pavement design guide uses empirical models which were adopted and modified from US design guides. As with any empirical model, the prediction capabilities are limited to the conditions for which it was developed. In USA, Mechanistic Empirical Pavement Design Guide (MEPDG) has been recently developed to account for increase in truck traffic and minimize premature failure of pavements. Since the new design uses mechanistic approach, it is expected that the design guide can better predict performance of pavements. In addition, mechanistic approach allows use of design guide for different pavement and environmental conditions by calibrating model parameters for …

Investigation Of The Geotechnical Properties Of Municipal Solid Waste As A Function Of Placement Conditions, Wilson W. Wong

Master's Theses

An investigation of the variability of engineering properties of municipal solid waste as a function of placement conditions was conducted. Limited data have been reported for the engineering properties of municipal solid waste (MSW) as a function of placement conditions. Wastes have high variability of engineering properties due to heterogeneity in composition and component size; influence from time based effects; and presence of compressible solids. Control of moisture content of MSW at the time of waste placement provides opportunity for increased capacity at a given landfill site due to higher compacted unit weight as well as for control of other …

Seismic Evaluation Of Clark County Critical Bridges Using Nonlinear Static Procedures, Ahmad Said Saad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bridges are vital connective elements in community transportation systems. In the past, bridges have been severely damaged by earthquakes. However, with proper mitigation techniques, such as bridge retrofit, severe earthquake damage to bridges can be avoided. Since the 1970’s, design codes underwent major changes with regard to seismic analysis and design provisions of structures and bridges. Meanwhile, one third of the nation’s 600,000 inventoried highway bridges are considered as either structurally deficient or functionally obsolete.

This study is a part of the “Earthquakes in Southern Nevada” project. Earlier in this project, buildings and bridges in southern Nevada were studied in …

Rampart Roads In The Peat Lands Of Ireland: Genesis, Development And Current Performance, Juan Pablo Osorio, Eric R. Farrell, Brendan C. O'Kelly, Tom Casey

Articles

The construction and improvement of roads on peat lands has always been a challenging task in geotechnical engineering. Rampart roads, which are a particular feature of the bog roads in Ireland, are caused by the excavation of peat from the roadsides over many years for use as a domestic fuel. The historical development of rampart roads and current performance under the added traffic loading is discussed. Various road improvement methods have been applied to improve the road ability to carry traffic and the technical aspects and performance of the methods are discussed. In particular, the performance of the improvement methods …

Expert System Design Guide For Lower Classification Roads Over High Pi Clays, Yaqi Wanyan

Open Access Theses & Dissertations

This research was focused on low-volume roads over expansive clayey soils in Texas. In spite of the redundant pavement designs recommended and widely used in Texas for roads in high PI clay areas, these pavements often fail prematurely. This failure occurs primarily because of the highly variable properties of the clayey subgrade throughout the year due to moisture fluctuations. The problematic nature of high PI clays, despite the fact that volumetric changes such as heaving are sometime considered in the design, is of concern since they contribute to roughness and longitudinal shrinkage cracking of the road, and as such the …

Sediment Budgets In The Irish Estuarine Environment, Kevin Motherway

Theses

A sediment budget is the quantification of sediment sources and sinks for natural physical systems such as rivers and estuaries.

This thesis has developed estuarine sediment budgets for Cork Harbour, Kinsale Harbour and Youghal Harbour. The thesis includes a literature review of the properties of sediment, river and estuary related sediment transport, sediment management and sediment related legislation and the approaches used to develop a sediment budget for an estuary system.

An extensive study of riverine suspended sediments discharging to the estuaries has been undertaken. Both surface grab samples and depth integrating suspended sediment samples were collected, tested and analysed. …

Effects Of Aggregates On Properties And Performance Of Mastics And Superpave Hot Mix Asphalt Mixtures, Francisco Aragão

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

Superpave, a set of advancements in testing devices and specifications for asphalt binders and mixtures, was limited to address the effects of aggregates. Because aggregates represent around 95% in mass of the asphalt mixtures, it is important to understand how these materials affect properties and performance of such mixtures. This research focus on how different types and contents of aggregates affect properties of mastics and asphalt mixtures, and their performance considering the viscoelastic nature of the asphalt material.

Five different types of aggregates and hydrated lime were used for sample fabrication together with two different binders. Several different tests were …

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

Sediment Transport In Rivers And Estuaries, John Clancy

Theses

The processes of erosion, transportation and sedimentation in rivers and estuaries have fascinated researchers for centuries. These processes have been active throughout geological time and have shaped the present landscape. To effectively study these processes analysis needs to be carried out at catchment scale level. Cork Harbour and its tributaries including the River Lee, the Owenabue River, the Glashaboy River, the Owennacurra River, and the Dungoumey River are analysed for the processes of sediment transport within their catchments and systems, and particularly river sediment loadings.

This thesis includes a literature review of the properties of sediment, river and estuary related …

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

A Dynamic Simulation Model Of Beach Sand Replenishment: A Case Study Of Santa Barbara, California, David Turbow, Steve Norwick, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Sediment deprivation from dam installments contributes to beach erosion yet the underlying physical and economic factors linking them together have traditionally been isolated during regional planning. In order to gain a better understanding of the behavior of a managed beach system, a dynamic simulation model was developed incorporating physical and monetary factors influencing the amount of available beach sand. The Santa Barbara littoral cell was chosen as a case study to evaluate the feasibility of beach preservation goals under scenarios in which annual sand replenishment funding, sand prices, or sediment recovery from behind dams were limiting factors to available beach …

Performance Comparison Of A Roundabout Versus Two-Way Stop Controlled (Twsc) Intersections, Deogratias Eustace

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

The superior safety record of modern roundabouts is well known in Western Europe, Australia and in most British-influenced countries around the world. The experience from a single modern roundabout installed in the City of Manhattan, Kansas, some three years ago, also shares the same experience. A major study of the performance of Manhattan, Kansas, modern roundabout was conducted at Kansas State University (KSU) and was co-sponsored by Mac-Blackwell National Rural Transportation Study Center, Kansas State University, and the City of Manhattan. The study examined three intersections, one modern roundabout and two Two-Way Stop Controlled (TWSC) intersections with similar traffic conditions. …