Civil and Environmental Engineering Commons^™

Structure Formation Of A Cement Stone With A Zeolite Containing Filler (Natrolite) And A Superplastificator, Anvar Ishanovich Adilkhodjayev, Ilkhom Abdullaevich Kadyrov, Kadyr Saparbaevich Umarov

Journal of Tashkent Institute of Railway Engineers

The article presents the results of studies of the hydration process of the compositions "cement + zeolite-containing rock + superplasticizer" using the methods of IR spectrometry, differential thermal analysis. The scientific and practical significance of the work results for building materials science and the construction industry is to establish the effectiveness of the use of complex additives in the preparation of cement concrete.

State And Prospects Of Production And Operation Of Synthetic Woven Belts (Table) For Load-Handling Devices (Hd) In The Republic Of Uzbekistan, Ibrohim Numanovich Abdullaev, Zhamoldin Dzhalalovich Akhmedov, Bakhodir Kushakovich Rakhmanov, Ruzikhon Toyirzhanovna Zhurabaeva

Journal of Tashkent Institute of Railway Engineers

In the world, the use of synthetic woven tapes (SWT) is increasing in various areas of life, including in construction. In particular, thanks to the development of production of high-strength synthetic fibers in such developed countries as Russia, USA, Germany, progress has been made in the creation and manufacture of heavy-duty lifting slings from STL, and on this basis to improve ergonomics and safety of installers, the safety of transported goods, the reduction of labor input and material on the load capacity.

Investigation Of The Longitudinal Hijacking Force From Friction Braking, Makhamadjan Mirakhmedovich Mirakhmedov, Gali-Askar Rustamovich Khalfin

Journal of Tashkent Institute of Railway Engineers

On the elements of the longitudinal profile, when the train is decelerated from friction, an additional force of theft occurs. By modeling the braking process, the dependence of the driving forces on the braking friction is close to linear. The result of theft also depends on the power of the anti-theft system, namely, the force of pressing the fastening terminal to the rail, the weakness of which can subsequently affect the safety of trains and cause the track to be thrown out.

Method For Evaluating The Residual Resource Of Long Designs, Sergey Vladimirovich Chizhov, Ulugbek Zabixullayevich Shermuxamedov, Sharofat Shavkatovna Kadirova

Journal of Tashkent Institute of Railway Engineers

The article describes a method for calculating the safety of extended structures, in particular tunnels. The probabilistic approach to solving the problem is analyzed using the reliability of the structure with the probability of failure-free operation and assessment of the residual life of the structure. These characteristics make it possible to predict the residual life of the structure within a time value until the design has exhausted its ultimate state. An assessment of the operational reliability of the structure is carried out by measuring and establishing existing structural defects. Based on the data obtained, an analysis was carried out and …

About The Technology Of Making Reinforced Concrete Sleep By Heating Concrete At Low Temperature, Turgunbaev Urinbek Jamolovich, Movluda Umirova

Journal of Tashkent Institute of Railway Engineers

The article discusses the properties of cement stone with the use of complex chemical additives to improve the technology for the production of sleepers from prestressed concrete. With the use of superplasticizer, the volume of intergranular space and, consequently, capillary porosity, which is a determining factor for both strength and frost resistance and corrosion resistance of concrete, are significantly reduced. Also, during thermo-wet processing, at a temperature of 40 ° C, there was no decrease in the strength of cement stone and sufficient strength at the initial stage of the curing period, 36 MPa with the addition of Glenium 27 …

About Properties Of Modified Gypsum Compositions With Slag Filler And Chemical Additive, Jumagul Raximberdievna Turgunbaeva

Journal of Tashkent Institute of Railway Engineers

The article presents the results of experiments to assess the effect of slag filler and chemical additives on the physical properties of the modified gypsum composition. In particular, it was shown that the water demand of building gypsum increases with an increase in the content of metallurgical slag in the composition. With its constant amount, an increase in the proportion of GLENIUM 27S superplasticizer additive does not affect the normal density value of the gypsum dough. This suggests that the presence of a plasticizing effect from the introduction of superplasticizer GLENIUM 27S. In addition, filling gypsum with metallurgical slag with …

Experimental Research Methodology For The Crack Resistance Of Large-Panel Buildings In Seismic Areas, Nigmat Baxramovich Shaumarov, Ulugbek Xakimovich Abdullayev

Journal of Tashkent Institute of Railway Engineers

The experience of the Tashkent, Spitak, Kyrgyz and Kamchatka earthquakes of recent years has led to the conclusion that there is a sufficient good seismic resistance of large-panel buildings with a narrow step of transverse load-bearing walls. One of the distinguishing structural features of buildings is considered to be the overlapping of individual multi-hollow panels with their support on special cantilevered outlets along the lateral surfaces of the transverse walls. Elements of the outer walls were made of expanded clay concrete with a compressive strength of about 200 kg / cm2. All structures were reinforced with flat welded frames made …

Investigation Of Way Embankment Stability On Movement Of High Speed Trains, Mirzakhid Khamitovich Miralimov, Shakhboz Ulugbekovich Normurodov

Journal of Tashkent Institute of Railway Engineers

In this paper is considered the problem related with a stressed state of railway embankments taking into account of dynamic loadings from high-speed trains. In the offered technical method is giving wave nature transmissions of dynamic loading from the passenger trains and their interaction of soil layers with various parameters. The design procedure gives a clear physical and mathematical pattern, where all formulas are in detail shown and simple for understanding. Calculation is conducted numerically in two stages. Considering from classical principles of structural mechanics, the first calculation stage of the railway structures includes deformation of the railway sleepers taking …

Research Of Properties Of Composite Elastomeric Material Filled With Montmorillonite Of Karakalpakstan With Nanoparticles, Bakhadir Bakhramovich Kakharov, Akhmadjan Ibadullaev, Elmira Ubaydullayevna Teshabaeva, Marziya Begdullayevna Muftullayeva

Journal of Tashkent Institute of Railway Engineers

The paper presents the results of studies on the effect of montmorillonite of Karakalpakstan with nanoparticles on the specific properties of composite elastomeric materials based on a mixture of rubbers SKMS-30 ARKM-15 (70%) and SKN-26 (30%). It was found that with an increase in the filler content in rubber, the recoverability of the rubber compound after deformation is significantly reduced. Moreover, the ability of the system to accumulate the energy of elastic deformation, i.e. the swelling of the extrudate (Re), largely depends on the specific geometric surface (Ssp) of montmorillonite of Karakalpakstan. Studies of the properties of rubbers showed that …

Innovative Technologies For Formless Forming Of Multi-Hollow Floor Slabs, Anvar Ishanovich Adilkhodjayev, V.M. Tsoy, K Umarov

Journal of Tashkent Institute of Railway Engineers

the article discusses the technology of non-formwork molding and reinforcement of hollow-core floor slabs. Optimal methods of concrete mixture compaction and reduction of cement consumption without loss of the required concrete strength are analyzed. The use of floor slabs developed using no-form molding technology in conditions of increased seismic activity.

About The Influence Of The Organosilicon Hydrophobizer "Gidrofob" On The Properties Of Non-Autoclave Gas Concrete, V.M. Tsoy, S. Hodjayev

Journal of Tashkent Institute of Railway Engineers

The article examines the effect of hydrophobizing additives on the normal density and setting time of the cement paste and the strength of the cement stone. We used an organosilicon additive - "Hydrophobe" as a water-repellent additive. As a result of research, it was found that the introduction of a water repellent agent, depending on its dosage, leads to a significant increase in the setting time and insignificantly affects the strength

Utility Of Vertically Integrated Liquid Water Content For Radar-Rainfall Estimation: Quality Control And Precipitation Type Classification, Bong Chul Seo, Witold F. Krajewski, Youcun Qi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study proposes a new estimation method for vertically integrated liquid water content (VIL) using radar reflectivity volume data and temperature sounding retrieved from the numerical weather model analysis. This method addresses uncertainty factors in conventional VIL estimation associated with the effects from the bright band (BB) and radar beam geometry near the radar site. The new VIL is then used for precipitation classification (convective/stratiform) and wind turbine clutter detection in the hope that the estimated VIL indicating vertical activities or development of precipitation systems will account for the two independent subjects together, in opposite ways. The non-precipitation radar echoes …

Development Of Novel Instrumentation And Methods To Investigate The Composition And Phase Partitioning Of Semivolatile And Intermediately Volatile Organic Compounds In Atmospheric Organic Aerosol, Claire Fortenberry

McKelvey School of Engineering Graduate Student Theses & Dissertations

Atmospheric particulate matter (PM) is ubiquitous in both indoor and outdoor air and is generally detrimental to human health. PM composed of particles with aerodynamic diameters less than 2.5 um (PM2.5) are related to adverse health outcomes including heart disease and respiratory disease. Fundamentally, particle physical properties such as size and hygroscopicity are dictated by chemical composition, which can be highly complex, particularly for organic aerosol (OA). In both outdoor and indoor air, OA is composed substantially of intermediately volatile and semivolatile organic compounds (I/SVOCs), which exist in both gas and particle phases under typical atmospheric conditions. The distribution of …

Chemistry Of Nanoscale Solids And Organic Matter In Sustainable Water Management Systems, Xuanhao Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

To alleviate global water scarcity and improve public health, engineered water treatment and management systems have been developed for purifying contaminated water and desalinating brackish or ocean water. These engineered systems provide substantial amounts of potable water and lessen environmental concerns about the release of contaminated water. Wastewater treatment plants (WWTPs), water desalination plants (WDPs), and managed aquifer recharge systems (MARs) are three representative sustainable water management (SWM) systems. But the operation of all three poses two fundamental questions: (1) What is the fate of nanoscale solids (e.g., engineered nanomaterials, naturally occurring nanoparticles) in SWM systems and how will their …

Optimization Of Window Positions For Wind-Driven Natural Ventilation Performance, Nari Yoon, Mary Ann Piette, Jung Min Han, Wentao Wu, Ali Malkawi

Civil and Architectural Engineering Faculty Research

This paper optimizes opening positions on building facades to maximize the natural ventilation’s potential for ventilation and cooling purposes. The paper demonstrates how to apply computational fluid dynamics (CFD) simulation results to architectural design processes, and how the CFD-driven decisions impact ventilation and cooling: (1) background: A CFD helps predict the natural ventilation’s potential, the integration of CFD results into design decision-making has not been actively practiced; (2) methods: Pressure data on building facades were obtained from CFD simulations and mapped into the 3D modeling environment, which were then used to identify optimal positions of two openings of a zone. …

Source Apportionment Of Ozone And Its Health Effects In North China Plain And Southeast U.S., Kaiyu Chen

LSU Doctoral Dissertations

Ground-level ozone (O₃), as one of six common air pollutants set by National Ambient Air Quality Standards from the U.S. Environmental Protection Agency (EPA), is of great interest due to its health and economical effects. However, O₃ contributions from different emission sources are not well understood due to its complicated nonlinear reactions. In this study, O₃ source apportionment methods and the applications are firstly reviewed to provide a comprehensive understanding for O₃ formations. Application of High-order Decoupled Direct Method (HDDM), brute force method (BFM), O₃ source apportionment technology (OSAT) and source-oriented method in O …

Estimation Of Evapotranspiration And Energy Fluxes Using A Deep-Learning-Based High-Resolution Emissivity Model And The Two-Source Energy Balance Model With Suas Information, Alfonso F. Torres-Rua, Andres Ticlavilca, Mahyar Aboutalebi, Héctor Nieto, Maria Mar Alsina, Alex White, John H. Prueger, Joseph Alfieri, Lawrence Hipps, Lynn Mckee, William Kustas, Calvin Coopmans, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

Surface temperature is necessary for the estimation of energy fluxes and evapotranspiration from satellites and airborne data sources. For example, the Two-Source Energy Balance (TSEB) model uses thermal information to quantify canopy and soil temperatures as well as their respective energy balance components. While surface (also called kinematic) temperature is desirable for energy balance analysis, obtaining this temperature is not straightforward due to a lack of spatially estimated narrowband (sensor-specific) and broadband emissivities of vegetation and soil, further complicated by spectral characteristics of the UAV thermal camera. This study presents an effort to spatially model narrowband and broadband emissivities for …

A System-Of-Systems Model To Simulate The Complex Emergent Behavior Of Vehicle Traffic On An Urban Transportation Infrastructure Network, Rayan Assaad, Cihan H. Dagli, Islam H. El-Adaway

Engineering Management and Systems Engineering Faculty Research & Creative Works

Transportation agencies face escalating challenges in forecasting the traffic demand. Traditional prediction methods focused on individual transportation sectors and failed to study the inter-dependencies between the different transportation systems. Hence, there is a need for more advanced and holistic modeling techniques. To this end, this paper models and analyses an urban transportation system-of-systems incorporating seven various systems: population and GDP, CO₂ emission, gasoline price and total vehicle trips, traffic demand, public and private transportation, transportation investment, and traffic congestion. Accordingly, this research simulates transportation networks as a collection of task-oriented systems that combine their resources to form a complex …

A System Dynamics Approach For Study Of Population Growth And The Residential Housing Market In The Us, Gasser Galal Ali, Islam H. El-Adaway, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The US Consensus bureau estimated the total construction spending at 1,320,305 Million Dollars, in February 2020, with an increase of 1.1% since last February. The construction market is large, and risky. Prediction of the market behavior, for several years ahead, is needed in order to take strategic investment decision for long and expensive projects. The goal of this research is to study the relationship between population growth and the housing market. To that end, a system dynamics model is developed. System dynamics is a top-down approach that starts with the high-level behavior of a complex system to simulate the behavior …

A System Dynamics Model For Construction Safety Behavior, Mohamad Abdul Nabi, Islam H. El-Adaway, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction Industry has always been reputed by its high incident rates and poor safety performance. Construction accidents are, in most cases, resulted from the unsafe behaviors of construction workers on site. The study of workers' behavior is crucial in order to understand the causation of unsafe behaviors. Therefore, the objective of this paper is to simulate construction safety behavior in order to predict the number of safety incidents and better understand their causation factors. The simulation model illustrates how construction system influences construction labors on site in terms of unsafe behavior. The standard leading indicators of safety performance are first …

An Agent-Based Model To Study Competitive Construction Bidding And The Winner's Curse, Amr Elsayegh, Cihan H. Dagli, Islam H. El-Adaway

Engineering Management and Systems Engineering Faculty Research & Creative Works

Reverse auction theory is the basis for competitive construction bidding process. The lowest bid method is utilized for selecting contractors in public projects. The winning contractor having the lowest bid value could be cursed when the submitted bid value results in negative profits. This is caused by many factors such as the contractor's estimation accuracy and markup. This is addressed in this paper by providing a model simulating the construction competitive bidding and the occurrence of the winner's curse. To this end, the authors show the extent to which the winner's curse affects the status of contracting companies. The objectives …

Evaluation Of Undrained Shear Strength Of Soil, Ultimate Pile Capacity And Pile Set-Up Parameter From Cone Penetration Test (Cpt) Using Artificial Neural Network (Ann), Md Ariful Hassan Mojumder

LSU Master's Theses

Over the years, numerous design methods were developed to evaluate the undrained shear strength, S_u, ultimate pile capacity and pile set-up parameter, A. In recent decades, the emphasis was given to the in-situ cone and piezocone penetration tests (CPT, PCPT) to estimate these parameters since CPT/PCPT has been proven to be fast, reliable and cost-effective soil investigation method. However, because of the paucity of a vivid comprehension of the physical problem, some of the developed methods incorporate correlation assumptions which might compromise the consistent accuracy. In this study, the Artificial Neural Network (ANN) was exerted using CPT data …

Nonlinear Dynamic Tests Of A Reinforced Concrete Frame Building At Different Damage Levels, Seyedsina Yousefianmoghadam, Mingming Song, Mohammad E. Mohammadi, Brittany Packard, Andreas Stavridis, Babak Moaveni, Richard L. Wood

Department of Civil and Environmental Engineering: Faculty Publications

This paper discusses the dynamic tests of a two-story infilled reinforced concrete (RC) frame building using an eccentric-mass shaker. The building, located in El Centro, CA, was substantially damaged prior to the tests due to the seismic activity in the area. During the testing sequence, five infill walls were removed to introduce additional damage states and to investigate the changes in the dynamic properties and the nonlinear response of the building to the induced excitations. The accelerations and displacements of the structure under the forced and ambient vibrations were recorded through an array of sensors, while lidar scans were obtained …

Intersection Illumination – Collision Correlation: How Does Street Lighting Affect Roadway Safety?, Josh R. Pinchek

Aurora

Understanding the relationship between roadway intersection safety and street lighting is essential to developing effective intersection lighting standards. This study uses data from the Ohio Department of Transportation’s (ODOT) Accident Databases (1 million+ accidents over 10 years) to explore the relationship between street lamps and accident occurrence via comparative statistics. Accident occurrence ratios, calculated based upon seasonally categorized, time-matched accident data are compared and reported with and without artificial lighting as a variable.

The results of the study indicate that artificial lighting is an important factor on accident rate occurrence via a correlation between lighting and roadway safety, guiding the …

Lead In Drinking Water And The Effectiveness Of Point-Of-Use Filtration, Donald Hopper

Honors Theses

Lead in drinking water has been proven harmful to human health and is an ongoing problem in the state of Mississippi. The goal of this thesis is to analyze lead contamination data in Mississippi, its implications, and possible short-term solutions for remediation. This was done through community outreach events and voluntary sampling in the Jackson, MS area, analyzing published data from the Mississippi State Department of Health, and conducting controlled sampling and testing in Lafayette County, MS.

Community engagement events were executed in which researchers informed citizens in the Jackson, MS area about the impacts of lead in drinking water …

College Of Engineering Senior Design Competition Spring 2020, 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 …

Beaver Creek Restorative Design Using Engineering In Nature, Lindsay M. Levatino

Senior Honors Projects, 2020-current

Stream restoration work can be instrumental for the wellbeing of an ecosystem. Located in the Shenandoah Valley in Virginia is Beaver Creek, a well-known spot for fly-fishing due to its pristine water conditions and open surroundings. In order to maintain these conditions, a 100-foot stretch of Beaver Creek needed to be restored to prevent further erosion, stabilize the banks, and enhance the natural habitats. The project involved excavating a sediment island, filling in an eroded bank, building a cross vane, and adding stakes. Local stakeholders came together to complete this project contributing their expertise, equipment, and time. The construction was …

Forecasting The Gas Fluiding Process Deposits With Application Of The Universal Regression Model, Sh.Zh. Mirboboev, Z.A. Razykov, S.K. Sokhoshko, Yu. Sultonov

Gorniy vestnik Uzbekistana

This article discusses mathematical methods for predicting the degree of flooding of gas deposits using the Universal regression model, using the example of actual data from observation wells of the Yamburgskoye oil and gas condensate field.

2-D Non-Linear Finite Element Analysis Of Folsom Dam: Seismically Induced Separation And Pore Pressure Along The Soil-Concrete Interface, Grace Amoussou

Master of Science in Civil Engineering Theses

The seismic soil-concrete interface stability of composite dams has been an area of interest to many researchers. However, the true interface behavior during a seismic event has not been well understood. During a ground shaking, bonding and de-bonding action along the interface may cause significant separation of soil and concrete surfaces, and such a separation may take place at any depth along the interface creating a stability concern for the overall dam. Moreover, the repetitive nature of bonding/debonding behavior may induce excess pore pressure along the interface, which in turn, may trigger a liquefaction failure or a hydraulic fracture in …

Quantitative Assessment Of Contested Water Uses And Management In The Conflict-Torn Yarmouk River Basin, Nicolas Avisse, Amaury Tilmant, David E. Rosenberg, Samer Talozi

Civil and Environmental Engineering Faculty Publications

The Yarmouk River basin is shared between Syria, Jordan, and Israel. Since the 1960s, Yarmouk River flows have declined more than 85% despite the signature of bilateral agreements. Syria and Jordan blame each other for the decline and have both developed their own explanatory narratives: Jordan considers that Syria violated their 1987 agreement by building more dams than what was agreed on, while Syria blames climate change. In fact, because the two countries do not share information, neither on hydrological flows nor on water management, it is increasingly difficult to distinguish between natural and anthropogenic factors affecting the flow regime. …