Civil and Environmental Engineering Commons^™

Effect Of Overburden Height On Hydraulic Fracturing Of Concrete-Lined Pressure Tunnels Excavated In Intact Rock: A Numerical Study, Moses Karakouzian, Mohammad Nazari-Sharabian, Mehrdad Karami

Civil and Environmental Engineering and Construction Faculty Research

: This study investigated the impact of overburden height on the hydraulic fracturing of a concrete-lined pressure tunnel, excavated in intact rock, under steady-state and transient-state conditions. Moreover, the Norwegian design criterion that only suggests increasing the overburden height as a countermeasure against hydraulic fracturing was evaluated. The Mohr–Coulomb failure criterion was implemented to investigate failure in the rock elements adjacent to the lining. A pressure tunnel with an inner diameter of 3.6 m was modeled in Abaqus Finite Element Analysis (FEA), using the finite element method (FEM). It was assumed that transient pressures occur inside the tunnel due to …

Investigation Of Tactile Sensory System Configuration For Construction Hazard Perception, Sayan Sakhakarmi, Jeewoong Park

Civil and Environmental Engineering and Construction Faculty Research

The application of tactile-based wearable devices to assist in navigation for people with low sight/low memory has demonstrated the feasibility of using such devices as a means of communication. Accordingly, a previous study in construction research investigated various parameters of tactile signals to develop a communicable system for potential application in construction hazard communication. However, the nature of construction limits the application of such devices to the body of construction workers, and it is important to understand sensor design parameters for improved communication, which has not been given significant attention yet. Therefore, this study aims to determine key design factors …

A New Uav-Based Module Lifting And Transporting Method: Advantages And Challenges, Jin Choi, Dong Bin Kim

Civil and Environmental Engineering and Construction Faculty Research

The modular construction technique is the one key technology that can substantially advance the competitiveness of the construction industry. However, the industry is having difficulty creating an optimum environment for broader and more effective use of modularization due to one key barrier: implementing a modular construction technique, that is, shipping modules from the fabrication shop to the build site. Multiple issues are potentially challenging to overcome, such as module size and center of gravity, rigging, tie-down, site access, site congestion, and transportation regulations, as well as the availability of local heavy lift equipment. The researchers propose to implement drones as …

A Pilot Study Of Identifying Execution Plan Differences For Accelerated Bridge Construction, Jin Choi, Elina Prajapati

Civil and Environmental Engineering and Construction Faculty Research

Accelerated bridge construction (ABC) is an innovative construction technique used to accelerate the construction of new bridges, as well as the renovation/replacement of existing bridges. Due to the benefits offered by ABC, transportation authorities have a higher preference in executing an accelerated approach over conventional bridge construction. The execution of an accelerated approach has differences when compared to the conventional approach, and it is important to identify such differences for the successful implementation of ABC projects. However, there have been no studies to identify such execution differences. Therefore, this study was conducted to identify execution plan differences relevant to ABC. …

Calibrating Cii Rt283s Modularization Critical Success Factor Accomplishments, Jin Choi, James T. O’Connor, Young Hoon Kwak, Rajarshi Ghimire

Civil and Environmental Engineering and Construction Faculty Research

Modularization is a well-known construction technique where sections of the job are moved from on-site to a fabrication shop. Previously, the researchers identified the 21 most influential Critical Success Factors (CSFs) for successful modularization and quantified the degree of each CSF’s accomplishment by conducting a survey with 19 subject matter experts, and a case study with three modular projects. Through this methodology, the findings relied on the experience of experts. However, still missing from the understanding of modularization CSFs is a validation of the current degree of each CSF’s accomplishment by examining actual modular projects using a sufficient number of …

Investigating Stakeholders' Perceptions Of Feasibility And Implications Of Modular Construction-Based Post-Disaster Reconstruction, Pedram Ghannad, Yong-Cheol Lee, Jin Ouk Choi

Civil and Environmental Engineering and Construction Faculty Research

Natural Disasters cause major adverse social and financial effects by destroying homes and infrastructures. For example, Hurricane Katrina in August 2005 damaged over 214,700 homes in New Orleans and forced over 800,000 citizens to live outside of their homes due to flooding. Thus, these disasters require a quick and efficient response to post-disaster housing issues and provide resources for temporary houses for short-term disaster relief and reconstruction of destroyed and damaged housing for full rehabilitation. Reconstruction of permanent housing for disaster victims is one of the most time-consuming activities in the post-disaster recovery process. However, time is a critical factor …

College Of Engineering Senior Design Competition Spring 2019, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

Modeling Driver-Pedestrian-Infrastructure Interactions At Signalized Midblock Crosswalks, Boniphace Kutela

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cities and metropolitan areas are increasingly facilitating pedestrians’ movement by the provision of pedestrian walking facilities. As pedestrian traffic increases, the risk of crash involvement increases, especially at midblock locations, where pedestrians are exposed to unsafe interactions with vehicular traffic. To improve pedestrians’ safety at midblock locations, various countermeasures are provided, which include signalized crosswalks. Several studies have analyzed driver-pedestrian interactions, as well as pedestrian-infrastructure interactions at signalized midblock crosswalks. However, more in-depth studies are necessary, due to shortfalls of study assumptions, which have led to the application of improper statistical models, as seen in the literature. Improved models are …

Opportunities And Challenges Of Modular Construction In A Hospitality Centric Environment, Shreyansh Paliwal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Modular construction techniques can substantially decrease project schedules and costs, effectively maintaining or increasing the quality of an end product by shifting a percentage of site-based work to an off-site fabrication shop. Modular construction can also significantly contribute to sustainability by reducing site disruption, reducing waste generated, creating better relocatability and reusability, causing less dust and noise pollution, and reducing the probability of loss, theft, and damage to equipment. The primary goal of this research is to identify the opportunities and challenges of implementing modular construction techniques in a hospitality-centric environment, by investigating the current situation and characteristics of modular …

Estimation Of Stage-Area-Storage Relationships In Reservoirs And Stage-Discharge Relationships In Rivers Using Remotely Sensed Data, Sailuj Shakya

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis estimates the relationships between the water surface levels and quantities of water in reservoirs and rivers using remotely sensed data without any field measurements. However, the accuracies of the estimates were validated using the field measurements from ground stations. The relationships between the water surface levels and quantities are fundamental for monitoring water quantities for the operation of hydraulic structures, as well as analyzing variability and changes in hydrology. Accessibility and transparency are big issues in establishing a monitoring system that can provide field validation of efforts to model global climate systems. Remote sensing has a capability of …

Assessing Simulated Transmissivity In Numerical Flow Models Of Complex Hydrogeology, Afan Tarar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accurately extracting a meaningful transmissivity, a target value within one order of magnitude of field estimates, in numerical models poses a significant challenge when modeling complex groundwater systems. Aquifer transmissivity is directly proportional to the aquifer thickness and the estimated aquifer hydraulic conductivity. In complex geologic conditions (especially in fractured systems) with multiple heterogeneous and anisotropic hydrogeologic units, transmissivity can vary over several orders of magnitude.

To extract a meaningful value of transmissivity from a numerical model, a simple five-layer MODFLOW model was constructed. Each layer in the model was assigned a fixed hydraulic conductivity and thickness. The model simulates …

Multi-Resolution Spatio-Temporal Change Analyses Of Hydro-Climatological Variables In Association With Large-Scale Oceanic-Atmospheric Climate Signals, Kazi Ali Tamaddun

UNLV Theses, Dissertations, Professional Papers, and Capstones

The primary objective of the work presented in this dissertation was to evaluate the change patterns, i.e., a gradual change known as the trend, and an abrupt change known as the shift, of multiple hydro-climatological variables, namely, streamflow, snow water equivalent (SWE), temperature, precipitation, and potential evapotranspiration (PET), in association with the large-scale oceanic-atmospheric climate signals. Moreover, both observed datasets and modeled simulations were used to evaluate such change patterns to assess the efficacy of the modeled datasets in emulating the observed trends and shifts under the influence of uncertainties and inconsistencies. A secondary objective of this study was to …

Comparison Of Zero Valent Iron (Zvi) And Zvi+Sludge For The Removal Of High Levels Of Hexavalent Chromium And Chlorate From Waters, Kenneth R. Greenhalgh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Remediation of contaminated groundwater is becoming increasingly more

important as much of the U.S. population relies on groundwater for their drinking water.

Contaminates such as Chromium, common pollutant at industrial waste sites, and

Hexavalent chromium which is toxic to humans, animals, and plants are major

concerns. Chlorate, another contaminate of concern, has been widely detected in

ground and surface water in the United States and even locally in Henderson Nevada at

the Nevada Environmental Response Trust (NERT) sites. To assist in mitigating this

issue, this research focuses on the removal of high levels of hexavalent chromium (ppm

range) (Cr(VI)) and …

Utilization Of Remote Sensing Data For Estimation Of The Groundwater Storage Variation, Gaurang Mistry

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater is the most extracted raw material, with an average withdrawal rate of 982 km3 per year, where 70 percent of the total groundwater withdrawn is used for agriculture globally (Margat & van der Gun, 2013). With climate change and increased water demands in recent years, monitoring the changes in the groundwater storage is of the utmost importance. This thesis presents an analysis that determines the rates, trends, and directions where groundwater storage is going in Pakistan. It also correlates fluctuations in groundwater storage with variations in precipitation and agricultural productivity in the country. The overall objectives of this thesis …

Chromium(Vi) And Oxyanion Remediation Of Vadose Zone Soils With Zero Valent Iron (Zvi) And Biological Reduction, Nicolas Kim Wong

UNLV Theses, Dissertations, Professional Papers, and Capstones

In areas with high industrial development, soil and groundwater are often heavily contaminated with hexavalent chromium [ Cr(VI) ], which commonly occurs as the oxyanions chromate ( CrO42- ) and dichromate ( Cr2O72- ). By itself, Cr(VI) is a common contaminant in various industrial wastes, but other oxyanions such as nitrate [ NO3- ], chlorate [ ClO3- ], and perchlorate [ ClO4- ] can appear with Cr(VI) as co-contaminants based on the type of industrial waste. Cr(VI) and ClO3- occur as co-contaminants in areas where sodium chlorate is manufactured as a bleaching agent for the pulp and paper industry (ERCO …

Optimization Of Photocatalytic Degradation Of Acid Blue 113 And Acid Red 88 Textile Dyes In A Uv-C/Tio2 Suspension System: Application Of Response Surface Methodology (Rsm), Ali Saber, David E. James, Soroosh Mortazavian

Civil and Environmental Engineering and Construction Faculty Research

Textile industries produce copious amounts of colored wastewater some of which are toxic to humans and aquatic biota. This study investigates optimization of a bench-scale UV-C photocatalytic process using a TiO2 catalyst suspension for degradation of two textile dyes, Acid Blue 113 (AB 113) and Acid Red 88 (AR 88). From preliminary experiments, appropriate ranges for experimental factors including reaction time, solution pH, initial dye concentration and catalyst dose, were determined for each dye. Response surface methodology (RSM) using a cubic IV optimal design was then used to design the experiments and optimize the process. Analysis of variance (ANOVA) was …

Changes In Snow Phenology From 1979 To 2016 Over The Tianshan Mountains, Central Asia, Tao Yang, Qian Li, Sajjad Ahmad, Hongfei Zhou, Lanhai Li

Civil and Environmental Engineering and Construction Faculty Research

Snowmelt from the Tianshan Mountains (TS) is a major contributor to the water resources of the Central Asian region. Thus, changes in snow phenology over the TS have significant implications for regional water supplies and ecosystem services. However, the characteristics of changes in snow phenology and their influences on the climate are poorly understood throughout the entire TS due to the lack of in situ observations, limitations of optical remote sensing due to clouds, and decentralized political landscapes. Using passive microwave remote sensing snow data from 1979 to 2016 across the TS, this study investigates the spatiotemporal variations of snow …

Health Benefits From Upgrading Public Buses For Cleaner Air: A Case Study Of Clark County, Nevada And The United States, John O. Olawepo, L.-W. Antony Chen

School of Public Health Faculty Research

Public transit buses, which move more than 5 billion passengers annually in the United States (U.S.), can contribute substantially to the environmental health burden through emitted air pollutants. As a leader in transforming to cleaner bus fleets, the Regional Transport Commission of Southern Nevada (RTC) has been transitioning from diesel to compressed natural gas (CNG) transit buses since 1999. By 2017, ~75% of RTC’s buses operating in Clark County, Nevada were CNG-powered. This study assesses the health benefits of the venture using the US Environmental Protection Agency’s (EPA) Co-Benefits Risk Assessment (COBRA) model, considering the emission and exposure changes from …

Water Quality Modeling Of Mahabad Dam Watershed–Reservoir System Under Climate Change Conditions, Using Swat And System Dynamics, Mohammad Nazari-Sharabian, Masoud Taheriyoun, Sajjad Ahmad, Moses Karakouzian, Azadeh Ahmadi

Civil and Environmental Engineering and Construction Faculty Research

The total phosphorus (TP) concentration, as the primary limiting eutrophication factor in the Mahabad Dam reservoir in Iran, was studied, considering the combined impacts of climate change, as well as the scenarios on changes in upstream TP loadings and downstream dam water allocations. Downscaled daily projected climate data were obtained from the Beijing Normal University Earth System Model (BNU-ESM) under moderate (RCP4.5) and extreme (RCP8.5) scenarios. These data were used as inputs of a calibrated Soil and Water Assessment Tool (SWAT) model of the watershed in order to determine the effects of climate change on runoff yields in the watershed …

Flow-Induced Stresses And Displacements In Jointed Concrete Pipes Installed By Pipe Jacking Method, Moses Karakouzian, Mehrdad Karami, Mohammad Nazari-Sharabian, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Transient flows result in unbalanced forces and high pressure in pipelines. Under these conditions, the combined effects of flow-induced forces along with sudden pipe displacements can create cracks in the pipeline, especially at the junctions. This situation consequently results in water leakage and reduced operational efficiency of the pipeline. In this study, displacements and stresses in a buried pressurized water transmission pipe installed by pipe jacking method are investigated using numerical modeling and considering interactions between fluid, pipe, and soil. The analyses were performed consecutively under no-flow, steady flow, and transient flow conditions, in order to investigate the effects of …

Modeling Of Grace-Derived Groundwater Information In The Colorado River Basin, Md Mafuzur Rahaman, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Groundwater depletion has been one of the major challenges in recent years. Analysis of groundwater levels can be beneficial for groundwater management. The National Aeronautics and Space Administration’s twin satellite, Gravity Recovery and Climate Experiment (GRACE), serves in monitoring terrestrial water storage. Increasing freshwater demand amidst recent drought (2000–2014) posed a significant groundwater level decline within the Colorado River Basin (CRB). In the current study, a non-parametric technique was utilized to analyze historical groundwater variability. Additionally, a stochastic Autoregressive Integrated Moving Average (ARIMA) model was developed and tested to forecast the GRACE-derived groundwater anomalies within the CRB. The ARIMA model …

Identification Of Critical Source Areas (Csas) And Evaluation Of Best Management Practices (Bmps) In Controlling Eutrophication In The Dez River Basin, Hadi Babaei, Mohammad Nazari-Sharabian, Moses Karakouzian, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Best Management Practices (BMPs) are commonly used to control pollution in the river basins. Prioritization of BMPs helps improve the efficiency and effectiveness of pollution reduction, especially in Critical Source Areas (CSAs) that produce the highest pollution loads. Recently, the Dez River in Khuzestan, Iran, has become highly eutrophic from the overuse of fertilizers and pesticides. In this basin, dry and irrigated farming produce 77.34% and 6.3% of the Total Nitrogen (TN) load, and 83.56% and 4.3% of the Total Phosphorus (TP) load, respectively. In addition, residential, pasture, and forest land uses together account for 16.36% of the TN and …

Gis Framework For Spatiotemporal Mapping Of Urban Flooding, Sayed Joinal Hossain Abedin, Haroon Stephen

Civil and Environmental Engineering and Construction Faculty Research

This research aims to develop a framework using the Geographic Information System (GIS) to perform modeling and mapping of flood spatiotemporal variation in urban micro-watersheds. The GIS-framework includes a workflow of several methods and processes including delineation of urban watershed, generation of runoff hydrographs, and time series mapping of inundation depths and flood extent. This framework is tested in areas previously known to have experienced flooding at the University of Nevada, Las Vegas main campus, including Black Parking Lot (Blacklot) and East Mall. Calibration is performed by varying Digital Elevation Model (DEM) resolution, rainfall temporal resolution, and clogging factor whereas …

Effects Of Enso On Temperature, Precipitation, And Potential Evapotranspiration Of North India’S Monsoon: An Analysis Of Trend And Entropy, Kazi Tamaddun, Ajay Kalra, Miguel Bernandez, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

The influence of El Niño Southern Oscillation (ENSO) on the north Indian temperature, precipitation, and potential evapotranspiration (PET) change patterns were evaluated during the monsoon season across the last century. Trends and shifts in 146 districts were assessed using nonparametric statistical tests. To quantify their temporal variation, the concept of apportionment entropy was applied to both the annual and seasonal scales. Results suggest that the El Niño years played a greater role in causing hydro-climatological changes compared to the La Niña or neutral years. El Niño was more influential in causing shifts compared to trends. For certain districts, a phase …

Evaluating Future Flood Scenarios Using Cmip5 Climate Projections, Narayan Nyaupane, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Frequent flooding events in recent years have been linked with the changing climate. Comprehending flooding events and their risks is the first step in flood defense and can help to mitigate flood risk. Floodplain mapping is the first step towards flood risk analysis and management. Additionally, understanding the changing pattern of flooding events would help us to develop flood mitigation strategies for the future. This study analyzes the change in streamflow under different future carbon emission scenarios and evaluates the spatial extent of floodplain for future streamflow. The study will help facility managers, design engineers, and stakeholders to mitigate future …

Calculation Of Access Charge For High Speed Rail Xpresswest Of Nevada, Sameeksha Sapkota

UNLV Theses, Dissertations, Professional Papers, and Capstones

XpressWest is a High Speed Rail (HSR) system that plans to connect Las Vegas with California at Palmdale. It will utilize the railway network of the California High Speed Rail (CAHSR) to connect Las Vegas with California destinations that include Los Angeles and San Francisco. For sharing the railway network of CAHSR, XpressWest will pay certain charge known as an access charge. The access charge is the fee paid by the train operator to the infrastructure owner for the addition of trains in a track. There are several access charge systems in the world. However, there is no study that …

Effect Of Curing Conditions On Mechanical Properties And Durability Of Concrete, Edgar Lazaro Salas-Borrero

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents the results for three different concrete mix designs with compression strengths of 4500 psi. The experiment was conducted in the Las Vegas area during the summer, from August 16th to October 12th, 2018, where temperatures and relative humidity was recorded daily, three times a day. In total, 135 concrete specimens (4” x 8”) were taken on site and were subjected to five different curing conditions.

For each concrete mix design, three concrete samples (4” x 8”) were taken and submitted for each curing condition, resulting in 45 cylinders for each concrete mix design. The same number of …

Surface Resistivity For Concrete Quality Assurance, Stanley Tat

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this study was to determine the effectiveness of SRT for concrete quality assurance and to evaluate the relationship between SRT and the three chloride ion ingress methods currently used by various State DOTs. Additionally, the influence of binder type and content, concrete age, and water-to cementitious materials ratio on the experimental results were also examined.

In this study, Type V Portland and three SCMs; namely fly ash, slag, and silica fume were used. Fine and coarse, aggregates were supplied by a local quarry. To evaluate the transport properties of the studied concretes, RMT, RCPT, and ACT were …

Performance-Based Economical Seismic Design Of Multistory Reinforced Concrete Frame Buildings And Reliability Assessment, Chunyu Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the next generation of seismic design methodology, performance-based seismic design (PBSD) method requires a structure satisfy multiple preselected performance levels under different hazard levels. Optimal PBSD methods provide different strategies to design the numerous variables, including strength, stiffness and ductility of each structural component. The overall goal of this study is to develop a new optimal PBSD method for multi-story RC moment frames. This method is capable of overcoming the deficiencies of existing optimal PBSD methods and can be implemented by the U.S. design practice. The proposed method minimizes construction cost and takes the limit of member plastic rotation …

College Of Engineering Senior Design Competition Fall 2018, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …