Civil and Environmental Engineering Commons^™

Active Rheological And Stiffening Control Of Cementitious Systems For Additive Manufacturing, Abdul Basit Peerzada

All Dissertations

Technological advancements and automation in the last two decades have made additive manufacturing of cementitious systems a reality. Among all the additive manufacturing techniques used for cementitious materials, layer-by-layer extrusion-based printing is the most used technique. For a layer-by-layer printing process, the requirements of cementitious materials vary from those of a conventional construction process. Typically, the cementitious materials are pumped to a print head using a positive-displacement pump. The pumpability of the cementitious material for a specific pumping system depends on its rheological properties. For effective pumping, the yield stress and plastic viscosity of a cementitious system should be low. …

Empirical Fragility Functions And Numerical Parametric Study For Buckling Of Steel Grain Bins Under High Wind Loads, Andrew Ruder

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

While rural infrastructure is critical to the agricultural industry, it has been historically more susceptible to damage and slower to recover following natural disasters than its urban and suburban counterparts. This has been made evident most recently by the events of the August 10, 2020, derecho in which rural regions in Iowa were among the hardest hit areas with sustained windspeeds exceeding 120 mph. Among the most frequently damaged structures in this event were corrugated steel grain bins, which farmers and co-ops use to dry and store certain commodities. Unlike most other critical structures, steel grain bins are not designed …

Evaluation Of Swelling Pressure And Shear Strength Of Inorganic Microfiber-Reinforced Bentonite For The Engineered Barrier System, Jose Maria Ferdinand Victoria Calaunan

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

Nowadays, the permanent disposal of high-level radioactive waste materials has been a primary concern in several countries. The deep geological repository, being the preferred disposal method across the globe, utilizes a network of engineered barriers to prevent the radioactive material from spreading throughout the facility and harming the natural environment. Part of this engineered barrier system (EBS) is the buffer material, which essential function is holding the radioactive waste-containing canister in place. However, the potential generation of desiccation cracks in this buffer material is imminent due to the heat emitted from the radioactive waste. Knowing the capability of inorganic fibers …

Improving Tc Drill Bit's Efficiency And Resistance To Wear By Graphene Coating, Reza Taheri, Mohsen Jalali, Ahmed Al-Yaseri, George Yabesh

Research outputs 2022 to 2026

Displaying a two-dimensional pure crystal carbon structure, Graphene is the strongest, yet thinnest substance discovered by scientists. Coating tungsten carbide (TC) drill bits with graphene to evaluate the effect of graphene on the wear, as well as the rate of penetration of the drilling bit was examined in this research. Two evaluation approaches were employed: one with employing ANSYS Software and the second by employing atomic pressure chemical vapor deposition (APCVD synthesis) in the laboratory to produce a monolayer graphene coating. The simultaneous software-based and lab-based testing were performed to increase the credibility of the results and minimize the potential …

The Influence Of Acidizing On Propped Fractures For Productivity Enhancement: Eagle Ford Laboratory Study, Mohsen Farrokhrouz, Abbas Taheri, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Hydraulic fracturing of tight formations and placing proppants within induced fractures are commonly performed in unconventional shale reservoirs all over the world, especially in North America. However, the overall recovery of these oil and gas resources is very low and hence, production enhancement is inevitable. This study investigated the acidizing of propped fractures as a recovery enhancement method in Eagle Ford shale samples. Experiments were designed using sample slabs having proppants between them. Differing parameters were examined to optimize the fracture conductivity through acidizing. For a range of confining pressures, the fracture conductivity was maximized by minimizing the proppant embedment. …

The Living Breakwaters Pdr Efforts Econcrete Resource Analysis, Guianina Ferrari, Shervon Stephens, Calvin O. Walters Jr.

Publications and Research

On October 29, 2012, Superstorm Sandy impacted 443,000 people and caused nearly $19 billion (about $58 per person in the US) worth of damage within New York City. As part of the New York City infrastructure reparation plan, the Living Breakwaters project in Tottenville addressed coastal resilience, allocating $100M of public funds to a series of artificial breakwaters by the southwest coast of Staten Island. Each breakwater is constructed and designed to mitigate water flow in storm events. ECOncrete, a primary element of the breakwater, is a specialty cast cementitious product that is marine organism-friendly that encourages biocalcification and photosynthesis. …

Nexuscapes: A Landscape Approach For A Transdisciplinary Water-Energy-Food Nexus Decision-Making Process, Fortino Acosta

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study develops a reliable transdisciplinary framework for complex ecological and social systems by characterizing, mapping, typifying, assessing, and testing enhanced water-energy-food nexus scenarios under critical time constraints, specialized skills, or sensitive data accessibility. Detached management of limited essential resources like fresh water, reliable energy from renewable sources, and nutritious food can jeopardize regional economies and governance. Using a novel landscape approach, this study recommends a decision-making the framework focused on the circular economy that induces collaboration among diverse sectors and brings strategic coordination, specificity, and magnitude to the proposed solutions. The study elaborates on a decision-making tool that integrates …

Identification Of Factors Contributing To Traffic Crashes By Analysis Of Text Narratives, Cristian D. Arteaga-Sanchez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The fatalities, injuries, and property damage that result from traffic crashes impose a significant burden on society. Current research and practice in traffic safety rely on analysis of quantitative data from crash reports to understand crash severity contributors and develop countermeasures. Despite advances from this effort, quantitative crash data suffers from drawbacks, such as the limited ability to capture all the information relevant to the crashes and the potential errors introduced during data collection. Crash narratives can help address these limitations, as they contain detailed descriptions of the context and sequence of events of the crash. However, the unstructured nature …

Application Of Experimentally Calibrated Numerical Models For Prediction Of Composite Masonry Prism Strength, James Bristow

UNLV Theses, Dissertations, Professional Papers, and Capstones

The composite masonry prism test is a common laboratory test to determine the compressive strength of a set of masonry prisms (f’mt) to verify that the composite masonry prism assembly, and more importantly, the constituent materials, are providing adequate strength. While constructing masonry structures, the subcontractors, designers, and inspectors rarely provide continuous supervision or inspection of the construction process. Accordingly, verification of grout mix design, mixed proportions, proper installation of blocks, placement of mortar, dimensions of joints, etc. are more traditionally performed on a periodic basis instead. However, through the use and review of the composite masonry prism test results, …

Effects Of Particle Size And Replacement Proportion Of Post-Consumer Glass In Concrete, Negasi Gebremichael

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concrete, next to water, is the most used material (Gagg, 2014), which consumes natural or manufactured aggregates and resource-intensive cement. Concrete is also a more wasteful construction material than timber and steel. Depleting the natural resource due to aggregate extraction and the environmental unfriendliness of cement production have left the construction industry with no choice. Reducing waste, reusing, or recycling can help conserve natural resources. In this regard, the construction industry constantly seeks full or partial replacement of concrete aggregates and cement with recycled material. Glass is a candidate for replacing the three major components: cement, fine aggregate, and coarse …

Development And Application Of A Safety Index For Transit Stops: A Case Study From Las Vegas, Nevada, Rithesh Shivuni

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research developed a methodology to evaluate safety proximate to transit stops through a Safety Index, identified key factors associated with fatal crashes proximate to bus transit stops, and illustrated the applications of these using a case study based on the Las Vegas metropolitan area in Nevada, USA. The methodology is based on motor vehicle crashes that involve pedestrians recorded in the proximity of transit stops, and the severity of the crash outcomes. It focused on crashes which involved pedestrians that occurred within walking distances of individual transit stops. The severity of the crash outcomes was classified based on the …

Automated Approach For The Enhancement Of Scaffolding Structure Monitoring With Strain Sensor Data, Sayan Sakhakarmi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction researchers have made a significant effort to improve the safety of scaffolding structures, as a large proportion of workers are involved in construction activities requiring scaffolds. However, most past studies focused on design and planning aspects of scaffolds. While limited studies investigated scaffolding safety during construction, they are limited to simple cases only with limited failure modes and simple scaffolds. In response to this limitation, this study aims to develop an automated scaffold monitoring approach capable of monitoring large scaffolds. Accordingly, this study developed an automated scaffold safety monitoring framework that leverages sensor data collected from a scaffold, scaffold …

Use Of Harsh-Braking Data From Connected Vehicles As A Surrogate Safety Measure, Nathaniel Patrick Edelmann

Boise State University Theses and Dissertations

Traffic safety may be analyzed with the use of surrogate safety measures, measures of safety that do not incorporate collision data but rather rely on the concept of traffic conflicts. Use of these measures provides several benefits over use of more traditional analysis methods with historical crash data. Surrogate measures eliminate the need to wait for crashes to occur to conduct a safety analysis. The amount of time required for enough crash data to accumulate can be significant, delaying safety analyses. Similarly, these measures allow for safety analysis to be conducted prior to crashes occurring, potentially calling attention to hazardous …

Characterizing Karst Mountain Watersheds Through Streamflow Response To Snowmelt, Daniel Meade Thurber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The climate in many parts of the Western US is characterized by cold, wet winters preceding long, dry summers. In the absence of precipitation, water supplies in these regions are sustained by melting snow and mountain groundwater. Changes in regional climate can reduce snow accumulation, accelerate melt, and prolong dry periods, all increasing the importance of groundwater on summertime water availability. In mountainous regions with limestone and dolomite geology, bedrock formations can host significant karst aquifers comprising dissolution-enhanced karst conduits which play an outsized and variable role in how precipitation is translated into streamflow. In this study, we considered an …

Optimization And Enhancement Of Co2 Sequestration In Industrial Wastes For Environmental Applications, Maisa El Gamal, Ameera F. Mohammad

All Works

This paper explores carbon capture and storage (CCS) through carbide lime waste (CLW), a by-product of acetylene production, under different conditions. This process is specifically designed to provide an onsite waste management solution for several industries that can easily be integrated into existing systems. In addition, the effect of the carbonation process on collected solids morphology and average particle size was studied. The structural and chemical characteristics of the carbonated carbide lime samples were investigated using X-ray diffraction, scanning electron microscopy, TGA analysis, and Raman spectroscopy. The effect of carbonation conditions on the total dissolved solids and change in pH …

Energy Dissipation Of Highly Convergent Chutes In Stilling Basins Of Concrete Dams, Rafael Morán, Miguel Ángel Toledo, Jaime I. Masides

Protections Conference

This article presents the results of a combination of experimental and numerical research on the performance of stilling basins of spillways with highly convergent chutes (HCC). The comparison between the energy dissipation of the stilling basins with flat slab and baffle blocks shows that the latest are more efficient. Because of that, the cost savings of using such blocks can be significant. The results obtained could be applied in different cases such as increasing the capacity of existing spillways and protecting dams against overtopping. The application of HCC spillways in new dams could lead to a reduction in the cost …

A Novel Computational Method To Compute Rock Scour Due To Dam Overtopping, Erik F. R. Bollaert

Protections Conference

Flood events generating potential risk for dam overtopping may become more frequently in the future, especially because of increasing climate change. Crest overflows at arch dams generally impact the downstream rock mass very close to the dam foundation. As such, any scour of the rock mass generated by this phenomenon may potentially endanger the stability of the dam and its appurtenant structures. Hence, pertinent assessment of this scour formation through space and time is becoming increasingly relevant to dam safety. This paper presents a novel computational method for detachment of prismatic rock blocks from their mass when impacted by high-velocity …

Bedrock Erosion In Swedish Spillways - A Methodology For Assessing Design Pore Pressures Aimed For Design Of Erosion Mitigation Via Reinforcement Of The Rock Mass, Per Eriksson, Jonas Persson, Carol-Oscar Nilsson

Protections Conference

This article presents a collection of literature and data that enables calculations of hydraulic pressures inside a structurally simplified rock mass. The causation between the pressure in the rock mass and the near plane-parallel turbulently flowing waters on natural surfaces of igneous rock is expressed. The article is mainly aimed at rock reinforcement calculations given magmatic rock types with high durability and large block size.

Erodibility Evaluation Of An Unlined Rock Spillway: Comparison Between The Erodibility Index Method And A New Method Based On Block Theory, Michael George, Cole Christiansen, Ariel Rickel, Benjamin Israel, George W. Annandale

Protections Conference

Following the 2017 events at the Oroville Dam spillways that prompted evacuation of nearly 200,000 downstream residents and resulted in over $1B USD repair costs, there is highlighted focus on evaluation of spillways (both lined and unlined) at dams across the USA. In the case of unlined channels, flow conditions are often complex which presents several challenges for erodibility evaluation given methods are often based on idealized circumstances. High-resolution data available for the site (both in terms of 3D point cloud geometry data for the rock mass and 3D CFD model simulations of flow conditions) permitted a more detailed analysis …

Hydro-Geotechnical Rock Scour Assessment At Petit-Saut Dam, Seven E. Pells, Fanar Al-Qassab, Felicia Weir, Anaïs Faivre, Thierry Leturcq, Benoit Blancher

Protections Conference

This paper presents a recommended design procedure for assessment of rock scour which is illustrated for the case study of Petit-Saut Dam in French Guiana. The methodology, referred to as a “hydro-geotechnical scour assessment”, promotes a multi-discipline approach, applying expertise in both rock mechanics and hydraulics, and guides the diagnosis of scour and response to risk by application of currently available scour assessment techniques.

Failure Thresholds For Rcc Crest Caps, Tony L. Wahl, Bryan J. Heiner, Jacob F. Kepler

Protections Conference

Overtopping protection using roller-compacted concrete (RCC) overlays is a common improvement made to address hydrologic deficiencies at existing small- to medium-height embankment dams. Overlays allow floods to pass over the dam while preventing erosion of the original embankment. The United States has many examples of such projects on both private and public dams, including many associated with federal agencies of the Departments of the Interior and Agriculture. For one project modified with an overlay in 1993, deterioration of the RCC and poor bonding between lifts has caused concern for stability of the 0.3-m (1-ft) thick RCC lifts that cap the …

First Application Of Articulated Concrete Block Armoring With A Stabilized Stone Drainage Layer, Jeremy R. Young, Jim Nadeau

Protections Conference

Results from recent hydraulic testing of Articulated Concrete Block (ACB) systems have shown variations in the level of the ACB surface is attributed to the movement of an unconfined stone drainage layer. This movement appears to be exacerbated by thicker drainage layers, higher overtopping depths, and longer test flumes. While the apparent movement did not constitute “threshold of performance” as currently defined by ASTM D7276 and D7277, there was a desire to mitigate movement of the stone drainage layer and maintain conservatism in ACB design and construction. This paper will review the findings of Nadeau and Wedin’s paper from Protections …

Applying The Submerged Jet Erosion Test To Embankment Dam Breach Modeling, Tony L. Wahl, Blake Armstrong

Protections Conference

The submerged jet erosion test (JET) is one of several methods available for quantifying erodibility of cohesive soils, a crucial input for modeling erosion and breach of embankment dams with models such as WinDAM, EMBREA (Morris 2011), and DL BREACH (Wu 2013; 2016a; 2016b). The JET was initially developed in the late 1980s as a relatively large-scale device with a 13-mm diameter nozzle creating an impinging jet that erodes a soil sample submerged in a 61-cm diameter tank. This first device was documented in an ASTM standard (D5852-1995), but the standard was withdrawn in 2016. In the last 15 to …

Structural Failure Of The Cohesive Core Of Rockfill Dams: An Experimental Research Using Sand-Bentonite Mixtures, Ricardo Monteiro-Alves, Rafael Moran, Miguel Á. Toledo, Javier Peraita

Protections Conference

This article presents experimental research focusing on the structural failure of the central core of a rockfill dam using sand-bentonite mixtures. It comprised an extensive geotechnical characterization of soil materials and mixtures, including compaction and strength tests, as well as the construction of 1 m high and 1.5 m wide physical models. The displacements of the cohesive cores were recorded using a tailored measuring system, based on a laser pointer and a mirror, designed to amplify the real displacements. The cohesive cores were extremely sensitive to small oscillations and behaved as rigid bodies, similar to concrete slabs with three fixed …

Overtopping Erodibility Analysis For A Steep-Sloped Rockfill Embankment Dam, Ariel Rickel, Michael F. George, Rob Millar

Protections Conference

Erosion of embankment material during an overtopping event is one of the major mechanisms of failure for earthfill dams. The ability to analyze the progression of overtopping failure can prove useful in assessing the breakthrough risk of the dam, which involves understanding the behavior of the material that the dam is comprised of. While there have been studies on the behavior of smaller-grained materials such as clays and sands (e.g. Hahn et al 2000; Coleman et al. 2002; Hanson et al. 2005; Hanson et al. 2011), few have focused on erosion of larger-grained rockfill embankments.

This paper presents the erosion …

Solar Chimney Power Plants: A Mini Review, Ahmed Reda, Waseem Salah, Ahmed Suwailem, Shehab Eldin Ahmed, Omar Lasheen, Amira Elkodama, Moustafa R. Shousha, Amr Ismaiel, Anas A. Rahman

Future Engineering Journal

The main investigations of a novel solar thermal application known as SCPP are summarized in this paper. It is a method of producing electricity from solar energy that relies on the fact that air rises when it is heated. An adequate position within a tall chimney can be utilized to position a turbine to turn it, creating an updraft that can be used to generate power. This system's specifications, design, construction, and use are all covered in the paper along with experimental and analytical research related to it. It also emphasizes the development and execution of SCPP programs.

Low-Cost, Low-Weight Test Rig Design For A Laboratory-Scale Twin Rotor Wind Turbine, Ahmed Ayoub, Ahmed Elzeedy, Mahmoud Elkordy, Eslam Ayad, Mohamed Waleed, Amira Elkodama, Amr Ismaiel

Future Engineering Journal

Multi-Rotor Wind Turbine (MRWT) has been proven advantageous over Single-Rotor Wind Turbine (SRWT) in many aspects. In order to study the performance of MRWT over SRWT, this work presents a low-cost and low-weight design for a test rig for laboratory-scale wind turbine configurations. The configurations under study are a single-rotor, and a twin-rotor of the same size with a diameter of 30 cm. Aerodynamic loads have been calculated using the Blade Element Momentum (BEM) method, then the loads were used for stress analysis over the test rig proposed. The test rig is designed on Solidworks and the aerodynamic and inertial …

Performance Comparison Of Several Control Algorithms For Tracking Control Of Pantograph Mechanism, Laylaa Mahmoud Eng, Mohamed Shamseldin Dr, Mohamed Sallam Dr, Abdelghany Mohamed Prof

Future Engineering Journal

A sort of parallel manipulator known as a pantograph robot mechanism was created primarily for industrial requests that required high precision and satisfied speed. While tracking a chosen trajectory profile requires a powerful controller. Because it has four active robot links and one robot passive link in place of just two links like the open chain does, it can carry more loads than the open chain robot mechanism while maintaining accuracy and stability. The calculated model for a closed chain pantograph robot mechanism presented in this paper takes into account the boundary conditions. For the purpose of simulating the dynamics …

Relative Rate Observer Self-Tuning Of Fuzzy Pid Virtual Inertia Control For An Islanded Microgrid, Ahmed H. Mohamed, Helmy M. El Zoghby, Mohiy Bahgat, A. M. Abdel Ghany

Future Engineering Journal

Expanding the usage of renewable energy in islanded microgrids leads to a reduction in its total inertia. Low inertia microgrids have difficulties in voltage and frequency control. That affected saving its stability and preventing a blackout. To improve low inertia islanded microgrids' dynamic response and save their stability, this paper presented relative rate observer self-tuning fuzzy PID (RROSTF-PID) based on virtual inertia control (VIC) for an islanded microgrid with a high renewable energy sources (RESs) contribution. RROSTF-PID based on VIC's success in showing remarkable improvement in the microgrid's dynamic response and enhancement of its stability. Moreover, it handles different contingency …

2022 Fall Engr333 Seminar Presentation, Jordan Tuter, Aidan Bakker, Samuel Hoover, Jessica Camp

ENGR 333

File for student presentation on Carbon Neutrality for Calvin University, given by students in the Fall 2022 class of ENGR333.