Engineering Commons^™

Impact Of Wet-Dry Cycle On Mechanical Properties Of Expansive Clay Under Low Overburden Stress, Md Ashrafuzzaman Khan

Civil Engineering Theses - Archive

The seasonal variation in the water content termed as drying-wetting cycle is one of the most important environmental factor that may cause the degradation of strength for expansive clay. Highway embankment within the north Texas region are mostly constructed on expansive clay and shallow slope failures pose a significant maintenance problem for the Texas Department of Transportation (TxDOT). Understanding the strength loss mechanism of the expansive clay will provide some useful guidelines to design embankment with adequate factor of safety for long term drained condition. Impact of wet-dry cycle on the high plastic clay strength was measured by several researchers …

Algorithms For Lidar Based Traffic Tracking: Development And Demonstration, Vamsi K. Bandaru

Open Access Theses

The current state of the art of traffic tracking is based on the use of video, and requires extensive manual intervention for it to work, including hours of painstaking human examination of videos frame by frame which also make the acquisition of data extremely expensive. Fundamentally, this is because we do not have observability of the actual scene from a camera which captures a 2D projection of the 3D world. Even if video were to be automated, it would involve such algorithms as RANSACK for outlier elimination while matching features across frames or across multiple cameras. This results in algorithms …

Response Of High-Strength Steel Reinforced Concrete Structures To Simulated Earthquakes, Lucas Laughery

Open Access Dissertations

In reinforced concrete (RC) structures expected to resist earthquake demands, substituting smaller amounts of high-strength steel for conventional steel reinforcement can help reduce reinforcement congestion and placement costs while keeping strength unchanged.

Provided cross-sectional dimensions remain unchanged, reducing the amount of longitudinal steel in a member will result in a member with similar initial stiffness but lower post-cracking stiffness. Nominal strength can be kept nearly the same if this reduction in the amount of steel is accompanied by a corresponding increase in the strength of the steel. The topic of this investigation is whether two frames with the same initial …

Modeling Of Frame Structures Undergoing Large Deformations And Large Rotations, Hui Liu

Open Access Dissertations

Numerical simulation of large-scale problems in structural dynamics, such as structures subject to extreme loads, can provide useful insights into structural behavior while minimizing the need for expensive experimental testing for the same. These types of problems are highly non-linear and usually involve material damage, large deformations and sometimes even collapse of structures. Conventionally, frame structures have been modeled using beam-frame finite elements in almost all structural analysis software currently being used by researchers and the industry. However, there are certain limitations associated with this modeling approach. This research focuses on two issues, in particular, of modeling frame structures undergoing …

Framework For Incorporating Probabilistic Building Performance In The Assessment Of Community Seismic Resilience, Henry V. Burton, Gregory Deierlein, David Lallemant, Ting Lin

Civil and Environmental Engineering Faculty Research and Publications

A framework is presented for incorporating probabilistic building performance limit states in the assessment of community resilience to earthquakes. The limit states are defined on the basis of their implications to postearthquake functionality and recovery. They include damage triggering inspection, occupiable damage with loss of functionality, unoccupiable damage, irreparable damage, and collapse. Fragility curves are developed linking earthquake ground motion intensity to the probability of exceedance for each of the limit states. A characteristic recovery path is defined for each limit state on the basis of discrete functioning states, the time spent within each state, and the level of functionality …

Finite Element Analysis For Astm C-76 Reinforced Concrete Pipes With Reduced Steel Cage, Amin Darabnoush Tehrani

Civil Engineering Theses - Archive

Reinforced concrete pipes (RCP) are composite pipes which have been widely used in the industry for more than ten decades. They are generally used for sewerage, water drainage, and industrial waste water. There are two methods for designing the RCP so that it will bear the soil weight and the live load on it: Indirect design (ID) and direct design (DD) methods. ASTM C76 (1) classifies pipes into five categories. The five categories of pipes have been classified in order of ascending pipe diameter with their required load and reinforcement’s area. Typically, there are two reinforcement types: circumferential and longitudinal. …

Infiltration Study Using Tdr Techniques, Saurav Sinha

Civil Engineering Theses - Archive

The study of water flow or infiltration in an unsaturated soil is a highly non-linear and complex problem, simultaneous verification of field and laboratory results is a convenient and practical approach to test the results. In this study, Time domain reflectometry (TDR) sensors are installed at three different locations close to a water body (Creek) in Arlington, Texas which is a part of the National Science Foundation Project titled “Cyper SEES: Type 2: Integrative Sensing and Prediction of Urban Water for Sustainable Cities (iSPUW)”. Time Domain Reflectometry (TDR) and Time Domain Transmissometry (TDT) sensors were deployed at five different depths …

A Decision Support System Tool For Dynamic Pricing Of Managed Lanes, Maryam Zabihi

Civil Engineering Dissertations - Archive

Congestion pricing and managed lanes (ML) have been recently gaining interest around the country as a congestion management tool and as a means of revenue generation for facility maintenance and expansion as well repayment of highway construction debts. Congestion pricing in MLs entails one of several strategies, including time of day pricing, dynamic pricing based on predicted/anticipated traffic conditions, and real-time dynamic pricing based on actual traffic conditions. The overall goal of this study has been to develop a Decision Support System (DSS) tool based on drivers’ revealed willingness to pay (WTP) values. This should determine more effective dynamic toll …

Evaluation Of Structural Capacity Of Epoxy-Coated Concrete Pipes And Its Interaction With Soil, Elmira Riahi

Civil Engineering Dissertations - Archive

Rehabilitation of concrete structures by using synthetic resins such as epoxy is increasing worldwide. Understanding the structural behavior of the resultant composite structure and the interaction between the coating and concrete can be beneficial in predicting performance of the rehabilitated structure. However, very little is known about the strength of the epoxy-coated concrete. This researcher conducted laboratory experiments designed to evaluate epoxy coated concrete specimens under different load configurations with an emphasis on its stress-strain characteristics. The tests include uniaxial compression cylindrical specimens, three-point and four-point bending and tests on beam specimens and three-edge bearing tests on concrete pipe specimens. …

Laboratory Characterization Of Ohio Gold Frac Sand, Maria Gabriela Alvarado Calle

Open Access Theses

The mechanical response of sand depends on state variables (such as density, stress state and fabric) and intrinsic variables (such as particle size distribution and particle shape). The mechanical response of sand is also a function of sand crushability. Recent research studying the cone penetration process in a unique digital image correlation (DIC) chamber is underway at Purdue University. The test sand is Ohio Gold Frac sand, which meets criteria regarding particle size and gradation related to elimination of chamber boundary and scale effects.

The mechanical behavior of this sand can be simulated by a suitable constitutive model, such as …

Role Of River Bathymetry In Hydraulic Modeling Of River Channels, Sayan Dey

Open Access Theses

Accurate geometric representation of the river channel is required for accurate hydraulic modeling of rivers. These are generally obtained through remote sensing techniques such as Light Detection and Ranging (LIDAR). However, these techniques lack the ability to model the submerged channel bed effectively and need to be complemented with surveyed bathymetric data for complete representation of the channel bathymetry, which can be time and cost prohibitive. An alternative to address this issue is to develop conceptual models that can estimate bathymetry.

This study aims to evaluate the potential of a conceptual model, the River Channel Morphology Model (RCMM) which estimates …

Visualizations Of Travel Time Performance Based On Vehicle Re-Identification Data, Stanley E. Young, Elham Sharifi, Christopher M. Day, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

This paper provides a visual reference of the breadth of arterial performance phenomena based on travel time measures obtained from reidentification technology that has proliferated in the past 5 years. These graphical performance measures are revealed through overlay charts and statistical distribution as revealed through cumulative frequency diagrams (CFDs). With overlays of vehicle travel times from multiple days, dominant traffic patterns over a 24-h period are reinforced and reveal the traffic behavior induced primarily by the operation of traffic control at signalized intersections. A cumulative distribution function in the statistical literature provides a method for comparing traffic patterns from various …

Seismic Response Of An Older Bridge In Nevada Under Maximum Considered Earthquake, Ryan Thomas Isaac

UNLV Theses, Dissertations, Professional Papers, and Capstones

Given the aging infrastructure in the United States, a study was conducted on an older bridge in Nevada to determine its performance under the maximum considered earthquake. A suite of eight synthetic site-specific ground motions, including a spectrum-matched “RSP” record, were applied along both the longitudinal and transverse axes of Bridge G-953 in Las Vegas, Nevada. The supplementary materials contain the original drawings of Bridge G-953 for reference, including changes to the expansion joints and the addition of cable restrainers at the in-span hinges. A detailed model, including the effects of column nonlinearity, material degradation such as shear keys, abutment …

Experimental Investigation Of Discharge Capacity Of Labyrinth Weirs With And Without Nappe Breakers, Omer Bilhan, Emin Emiroglu, Carol J. Miller

Civil and Environmental Engineering Faculty Research Publications

Labyrinth weirs provide higher discharge capacity than conventional weirs, with the ability to pass large flows at comparatively low heads. Labyrinth weirs are primarily used as spillways for dams where the spillway width is restricted. In recent years, many research investigations have considered the hydraulic performance of labyrinth weirs, particularly as dependent on the geometric features. The previous work has improved the design basis for such weirs. However, their design still requires experimentally derived and generalized performance curves. It is especially important to observe the behavior of the weir nappe to ensure the design provides hydraulic optimization and to account …

Soil-Bentonite Slurry Trench Cutoff Wall Closeout Report, Daniel Ruffing

NSF Soil-Bentonite Slurry Trench Cutoff Wall Documents

Assessment report of the construction of a soil-bentonite slurry wall including milestone dates, work description, and quality control.

Development And Assessment Of A Groundwater Sustainability Index In Climatically Diverse Groundwater Irrigated Regions In Nebraska, Maria A. Mulet Jalil

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The aim of this research was to evaluate the impact of regional change in ET on groundwater level changes and the assessment and development of a groundwater sustainability index for climatically diverse regions across Nebraska during 2000-2014. Irrigation in the selected regions is predominantly supplied by groundwater. The hypothesis is that groundwater use can become sustainable if the regional evapotranspiration (ET) is managed so that it equals the ET of vegetation that is native to the region. Site locations were Box Butte, Chase, Dundy, Holt LNNRD and York Counties and 3 ecosystems were evaluated: native vegetation, dryland and irrigated cropping …

Fire-Spotting Modelling And Parametrisation For Wild-Land Fires, Inderpreet Kaur, Gianni Pagnini

International Congress on Environmental Modelling and Software

This article describes a mathematical formulation for simulating the effects of firebrands on the propagation of the wild-land fires. Among the different approaches available in literature, this formulation is defined in a way to provide a versatile approach for application to operational wildfire models. Most of the operational wildfire models like WRF-SFIRE and ForeFire model only the evolution of the fire-line according to the definition of the rate of spread, fuel characterisation and the average fire properties and concurrent atmospheric conditions. But this information is not enough to simulate the effects of turbulence and fire-spotting. The formulation presented here can …

A Generator Of Landuse Application For Complex And Heterogeneous Agricultural Practices, Odile Leccia-Phelpin, Jean-Marie Lescot, Françoise Vernier

International Congress on Environmental Modelling and Software

Non-point source pollution from agriculture has become a major concern for water managers and institutional stakeholders. To reduce diffuse pollution, agricultural conservation measures are widely used with efficiency. On non-monitored territories environmental modelling enables the assessment of their long term impacts on water and soils and to evaluate land-use change scenarios. We developed an innovative Generator of Landuse (GenLU) application in order to build up multi-year spatial crop successions from identified crop rotations with their related management schedule s. GenLU can be used solely for generating landuse or coupled with the Soil and Water Assessment Tool (SWAT) model so as …

Water Supply System Classification For Water Quality Improvement, Bruno Melo Brentan, Gustavo Meirelles Lima, Edevar Luvizotto Junior, Joaquín Izquierdo, Rafael Pérez-García

International Congress on Environmental Modelling and Software

Universal access to drinkable water is a constitutional right guaranteed in Brazil. However, not all cities in this country are able to supply the population with the expected quality. Important actions should be taken to improve the supply of drinkable water. To define a strategic plan for this purpose, classification tools can facilitate the design of plans, by grouping cities with similar quality conditions. During the last decades, neural network approaches have been used in environmental models, allowing more accurate representation of some complex systems. This work proposes the use of self-organizing maps (SOM’s) coupled with the k-means algorithm …

Optimal Land Use?! – A Review On Optimization Techniques Used In Multi-Criteria Decision Analysis, Andrea Kaim, Anna Cord, Martin Volk

International Congress on Environmental Modelling and Software

Agriculture, forest management, conservation planning and other related disciplines have specific land use demands, and thus different perspectives on how land should be used in an “optimal way”. One way to solve arising land use conflicts is employing the ecosystem services concept together with methods from the field of multi-criteria decision analysis (MCDA). Especially optimization techniques provide the possibility to include socio-economic and ecological aspects as well as the protection of biodiversity. In this study, we give an overview of these methods, focusing especially on their application in agricultural areas. We explore their abilities for the identification of ecosystem service …

The Economics Of Agricultural Water Productivity In The Blue Nile, Imeshi Weerasinghe, James Booker, Wim Bastiaanssen, Lisa-Marie Rebelo, Ann Van Griensven

International Congress on Environmental Modelling and Software

Agricultural Water Productivity (AWP) is often simplified as the ‘crop per drop’, described as the output in terms of yield or biomass per unit of water input. This purely physical measure of Water Productivity (WP) using only a single factor input (water) does not consider: (1) the level of other inputs used in conjunction with water, (2) the opportunity cost of water as an input, (3) the value of the output and (4) the costs of production for different crops. This study presents a justification and methodology for incorporating these factors into WP indicators. The application of these extensions to …

Atlas: A Tool To Model Spatial-Temporal Dynamics Of Processes Influencing Ecosystem Services, Hugo Thierry, Aude Vialatte, Claude Monteil, Annie Ouin

International Congress on Environmental Modelling and Software

Biodiversity provides various benefits to humankind throughout what is defined as ecosystem services. Within a specific ecosystem, a wide range of ecosystem services can be identified. During the past decades, human intervention has aimed to increase some services such as food production through agricultural intensification, at the expense of other services such as water regulation. Mapping, evaluating and quantifying each of these ecosystem services provided by biodiversity to crop production could help to increase the multi-functionality of agricultural landscapes. In this context, we developed a spatially-explicit model called ATLAS (AgriculTural LandscApe Simulator). ATLA …

Understanding The Relationships Between Sanitation And Health In Nicaragua And Honduras, Through Data Mining Tools, Ginevra Marina Lazerini, Josep Nualart, Sergio Ruiz-Cayuela, Maialen Urbina, Miquel Sànchez Marrè, Karina Gibert

International Congress on Environmental Modelling and Software

The aim of this work is to analyze water and sanitation supply data from Nicaragua and Honduras by using different data mining tools. The data has been provided by SIASAR (Rural Water and Sanitation Information System), which is a water and sanitation management and information platform created through the joint effort of different Central American Governments and the World Bank. In the study data from a survey performed in all the rural communities in Nicaragua and in a sample of the rural communities in Honduras from 2012 to 2015 is analyzed. Database contains 10206 communities described by 23 numerical variables …

Data-Driven Wildfire Behaviour Modelling: Application Of Firefly To Field-Scale Grassland Controlled Burns, M. C. Rochoux, C. Zhang, D. Lucor, S. Ricci, A. Trouve

International Congress on Environmental Modelling and Software

Assessing epistemic uncertainties is now considered as a milestone for improving numerical predictions of a dynamically evolving system. The objective of this project is to demonstrate the benefits of data assimilation combined with sensor observations of the fire front position to both quantify and reduce the uncertainties in wildfire behaviour forecasting capability. The challenges found on the route to modelling wildfire behaviour are two-fold. There is the modelling challenge associated with providing accurate representations of the multi-scale multi-physics processes governing wildfire dynamics. There is also the data challenge associated with providing accurate estimates of the environmental conditions (biomass moisture, near-surface …

Resilience Of Punta S’Aliga Barrier Beach To Storm Impacts, Andrea Sulis

International Congress on Environmental Modelling and Software

Beach and dune provide natural defense against erosion and flooding, and associated mitigation measures are classical coastal engineering problems studied by many researchers. Winter storms cause severe erosion leading to dune breaching and then flooding of the hinterland areas. Resiliency of a barrier beach depends on the ability of the dune (resistor) to recover in height and extent following storms. Whereas erosion of the beach and dune occurs over hours and days, it can be years to decades before the beach and dune are able to recover to their pre-storm state. In the last two decades, numerical modelling methods have …

E3.Pt – An E3 Portabledyme Model For Portugal, Anett Großmann, Frank Hohmann

International Congress on Environmental Modelling and Software

E3 models are environmentally extended economic models. They are extensively used for impact assessment of energy, climate and resource policies at national and international level. E3 models have proven to be suitable tools for quantifying effects on the economy, environment and energy system. Usually, the structure and documentation of such models are only accessible by the model builders. They are facing the allegation to be a "black box" meaning that only their creators are able to operate and fully understand the model system. Decision makers are often only engaged at the end of the model building process to discuss the …

A Markov Decision Process Model To Compare Ecosystem Services Provided By Agricultural Landscapes, Sabrina Gaba, Nathalie Peyrard, Régis Sabbadin, Julia Radoszyckic

International Congress on Environmental Modelling and Software

One current challenge in managing agricultural landscapes, is to reach a trade-off between provision of food and biodiversity conservation. Two extreme land-use strategies, land sharing and land sparing, are often discussed. The design of decision rules for allocating crops and lands for biodiversity conservation (e.g. grasslands) can be formalized as an optimization problem. However the target to optimize, representing the trade-off between ecosystem services (ES) can be complex to model since ES are usually not defined on comparable scales and may rely on different sides of biodiversity. Here, we will investigate how landscape composition and structure affect the magnitude of …

A Framework For Decision-Making In Cases Of Invasive Species, Peter A. Khaiter, Marina G. Erechtchoukova, Sina Roushan

International Congress on Environmental Modelling and Software

Invasion of nonindigenous species is one of the most pressing global challenges, causing substantial environmental, economic and social harm. Invasion of alien species alters the composition, structure and functioning of invaded ecosystems as well as the services they generated before the invasion. Decisions about the management of invasive cases are inherently difficult because of the multifactorial and multiattribute scope of the problem. In particular, the resilience limits of invaded ecosystems to fully recover original, pre-invaded states remain unclear. To facilitate management efforts, decision-makers and environmental practitioners require a framework integrating relevant knowledge and acting as a supporting expert system. The …

A Mathematical Model For Ghg From Sb-Mbr: Calibration By An Innovative Protocol, Giorgio Mannina, Alida Cosenza

International Congress on Environmental Modelling and Software

A mathematical model to quantify greenhouse gases (GHG) (carbon dioxide, CO₂ and nitrous oxide, N₂O) for a membrane bioreactor (MBR) is presented. The model has been applied to a pilot plant with a pre-denitrification MBR scheme. The pilot plant was cyclically filled with real saline wastewater according to the fill-draw-batch operation. The model was calibrated by adopting a specific protocol based on extensive field dataset. Standardised Regression Coefficient (SRC) method was adopted to select the most influential model factors to be calibrated. Results related to SRC method show that among the important model factors a key role …

Sectorization Of Intermittent Water Supply Networks Based On Graph Theory And Clustering Techniques, Amilkar E. Ilaya-Ayza, David Ayala-Cabrera, Joaquín Izquierdo, Enrique Campbell, Rafael Pérez-García

International Congress on Environmental Modelling and Software

Intermittent water supply is the form of access to water in many countries around the world. It is very common that design, operation, maintenance and, in general, decision-making in these systems are performed using tools originally developed for systems with continuous supply, which are not adequate. However, these tools can be reasonably applied to network sectorization of intermittent supply networks. We propose a sectorization methodology for networks that do not have the possibility of working with continuous supply. In addition, to ensure sufficient pressure, sector design must guarantee equity in the supply. Furthermore, it is not enough to establish sector …