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2019

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Articles 1291 - 1320 of 1769

Full-Text Articles in Civil and Environmental Engineering

Review Of Fiber Optic Sensors For Structural Fire Engineering, Yi Bao, Ying Huang, Matthew S. Hoehler, Genda Chen Feb 2019

Review Of Fiber Optic Sensors For Structural Fire Engineering, Yi Bao, Ying Huang, Matthew S. Hoehler, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Reliable and accurate measurements of temperature and strain in structures subjected to fire can be difficult to obtain using traditional sensing technologies based on electrical signals. Fiber optic sensors, which are based on light signals, solve many of the problems of monitoring structures in high temperature environments; however, they present their own challenges. This paper, which is intended for structural engineers new to fiber optic sensors, reviews various fiber optic sensors that have been used to make measurements in structure fires, including the sensing principles, fabrication, key characteristics, and recently-reported applications. Three categories of fiber optic sensors are reviewed: Grating-based …


Maximum Coverage Capacitated Facility Location Problem With Range Constrained Drones, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi Feb 2019

Maximum Coverage Capacitated Facility Location Problem With Range Constrained Drones, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Given a set of demand and potential facility locations and a set of fully available charged drones, an agency seeks to locate a pre-specified number of capacitated facilities and assign drones to the located facilities to serve the demands. The facilities serve as drone launching sites for distributing the resources. Each drone makes several one-to-one trips from the facility location to the demand points and back until the battery range is met. The planning period is short-term and therefore the recharging of drone batteries is not considered. This paper presents an integer linear programming formulation with the objective of maximizing …


Large-Strain Strength Of Polymer-Modified Kaolinite And Fly Ash-Kaolinite Mixtures, Xin Kang, Junnan Cao, Bate Bate Feb 2019

Large-Strain Strength Of Polymer-Modified Kaolinite And Fly Ash-Kaolinite Mixtures, Xin Kang, Junnan Cao, Bate Bate

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Polymers have gained gradual attention in soil stabilization as a sustainable alternative to inorganic counterparts such as cement. However, the effects of polymers on the strength of soils and soil-waste mixtures are still unclear. Meanwhile, waste recycling has been important in fostering a sustainable environment in recent decades. To solve the deficiency in knowledge, large-strain strength of polymer-modified kaolinite (KA) and Class-F fly ash-kaolinite mixtures (FAKAs) was investigated with isotropically consolidated undrained triaxial compression tests. Both synthetic polymer (polyethylene oxide, PEO) and naturally occurring biopolymers (chitosan and xanthan gum) were used. An interface model was also proposed to account for …


Aid Project Summary Report For Intelligent Compaction, David Q. Hunsucker, Kean H. Ashurst Jr., Brad W. Rister Feb 2019

Aid Project Summary Report For Intelligent Compaction, David Q. Hunsucker, Kean H. Ashurst Jr., Brad W. Rister

Kentucky Transportation Center Research Report

This study reviews data from five roadway construction projects on which intelligent compaction (IC) techniques were used to achieve the more uniform compaction of road-building materials. Kentucky Transportation Center (KTC) researchers looked at IC data collected from these projects — resulting in the production of eight analyzable data sets — to determine whether they complied with the special construction note included in contract documents. The report also compares the intelligent compaction measurement value (ICMV) collected on each project to traditional laboratory results. Researchers used Veta software to analyze geospatial data collected from IC machines during construction work. Of the data …


Closed-Form Solution For Curling Responses In Rigid Pavements, Jaime Hernandez, Imad L. Al-Qadi Feb 2019

Closed-Form Solution For Curling Responses In Rigid Pavements, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

Closed-form expressions for calculating stresses and displacements of partially restrained concrete pavement caused by a linear temperature gradient are presented. Translational and rotational linear elastic springs along the slab edges defined the partial restraint. In addition to plate theory behavior, the model assumes linear elastic concrete and an infinitely long slab resting on a Winkler foundation. The solutions of curling stresses and displacements were validated using the finite-element (FE) method and quantified the effect of semirigid connections, slab and foundation material properties, and slab thickness and width on them. Rotational and translational restraints, which can be related to joint condition …


Deficit Irrigation Management Of Maize In The High Plains Aquifer Region: A Review, Daran Rudnick, Sibel Irmak, C. West, J.L. Chavez, I. Kisekka, T.H. Marek, J.P. Schneekloth, D. Mitchell Mccallister, V. Sharma, K. Djaman, J. Aguilar, M.E. Schipanski, D.H. Rogers, A. Schlegel Feb 2019

Deficit Irrigation Management Of Maize In The High Plains Aquifer Region: A Review, Daran Rudnick, Sibel Irmak, C. West, J.L. Chavez, I. Kisekka, T.H. Marek, J.P. Schneekloth, D. Mitchell Mccallister, V. Sharma, K. Djaman, J. Aguilar, M.E. Schipanski, D.H. Rogers, A. Schlegel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigated agriculture is a major economic contributor of the High Plains Region and it primarily relies on the High Plains Aquifer as a source of water. Over time, areas of the High Plains Aquifer have experienced drawdowns limiting its ability to supply sufficient water to sustain fully irrigated crop production. This among other reasons, including variable climatic factors and differences in state water policy, has resulted in some areas adopting and practicing deficit irrigation management. Considerable research has been conducted across the High Plains Aquifer region to identify locally appropriate deficit irrigation strategies. This review summarizes and discusses research conducted …


From Micro To Macro-Contaminants: The Impact Of Low-Energy Titanium Dioxide Photocatalysis Followed By Filtration On The Mitigation Of Drinking Water Organics, Brooke K. Mayer, Carlan Johnson, Yu Yang, Nicole Wellenstein, Emily K. Maher, Patrick J. Mcnamara Feb 2019

From Micro To Macro-Contaminants: The Impact Of Low-Energy Titanium Dioxide Photocatalysis Followed By Filtration On The Mitigation Of Drinking Water Organics, Brooke K. Mayer, Carlan Johnson, Yu Yang, Nicole Wellenstein, Emily K. Maher, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

This study evaluated strategies targeting macro- and micro-organic contaminant mitigation using low-energy titanium dioxide photocatalysis. Energy inputs of 1, 2, and 5 kWh m−3 resulted in incomplete oxidation of macro-organic natural organic matter, signified by greater reductions of UV254 and specific ultraviolet UV absorbance (SUVA) in comparison to dissolved organic carbon (DOC). The rate of UV254 removal was 3 orders of magnitude greater than the rate of DOC degradation. Incomplete oxidation improved operation of downstream filtration processes. Photocatalysis at 2 kWh m−3 increased the bed life of downstream granular activated carbon (GAC) filtration by 340% relative …


Toxicity Of Various Pyrolysis Liquids From Biosolids On Methane Production Yield, Seyedfatemeh Seyedi, Kaushik Venkiteshwaran, Daniel Zitomer Feb 2019

Toxicity Of Various Pyrolysis Liquids From Biosolids On Methane Production Yield, Seyedfatemeh Seyedi, Kaushik Venkiteshwaran, Daniel Zitomer

Civil and Environmental Engineering Faculty Research and Publications

Aqueous pyrolysis liquid (APL) is a high-COD byproduct of wastewater biosolids pyrolysis that is comprised of numerous complex organic compounds and ammonia nitrogen (NH3-N). One potential beneficial use of APL is as a co-digestate to produce more biogas in anaerobic digesters. However, some APL organics and NH3-N are known to inhibit methane-producing microbes. Autocatalytic pyrolysis which uses previously-produced biochar as a catalyst during biosolids pyrolysis, increases energy-rich py-gas while eliminating bio-oil production and reducing COD concentration in the APL (catalyzed APL). However, the catalyzed APL still has a high organic strength and no suitable treatment strategies …


The Bridge Newsletter Spring 2019, Missouri University Of Science And Technology Feb 2019

The Bridge Newsletter Spring 2019, Missouri University Of Science And Technology

The Bridge Newsletter

-Building better aerogels
-Bridge repair needs
-Incoming ASCE President speaks


Biomaterial Substrate Modifications That Influence Cell-Material Interactions To Prime Cellular Responses To Nonviral Gene Delivery, Amy Mantz, Angela K. Pannier Feb 2019

Biomaterial Substrate Modifications That Influence Cell-Material Interactions To Prime Cellular Responses To Nonviral Gene Delivery, Amy Mantz, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gene delivery is the transfer of exogenous genetic material into somatic cells to modify their gene expression, with applications including tissue engineering, regenerative medicine, sensors and diagnostics, and gene therapy. Viral vectors are considered the most effective system to deliver nucleic acids, yet safety concerns and many other disadvantages have resulted in investigations into an alternative option, i.e. nonviral gene delivery. Chemical nonviral gene delivery is typically accomplished by electrostatically complexing cationic lipids or polymers with negatively charged nucleic acids. Unfortunately, nonviral gene delivery suffers from low efficiency due to barriers that impede transfection success, including intracellular processes such as …


Meaningful Learner Information For Mooc Instructors Examined Through A Contextualized Evaluation Framework, Kerrie Douglas, Mitch Zielinski, Hillary Merzdorf, Heidi Diefes-Dux, Peter Bermel Feb 2019

Meaningful Learner Information For Mooc Instructors Examined Through A Contextualized Evaluation Framework, Kerrie Douglas, Mitch Zielinski, Hillary Merzdorf, Heidi Diefes-Dux, Peter Bermel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Improving STEM MOOC evaluation requires an understanding of the current state of STEM MOOC evaluation, as perceived by all stakeholders. To this end, we investigated what kinds of information STEM MOOC instructors currently use to evaluate their courses and what kinds of information they feel would be valuable for that purpose. We conducted semi-structured interviews with 14 faculty members from a variety of fields and research institutions who had taught STEM MOOCs on edX, Coursera, or Udacity. Four major themes emerged related to instructors’ desires: (1) to informally assess learners as an instructor might in a traditional classroom, (2) to …


17-07 Phase-Ii: Community-Aware Charging Station Network Design For Electrified Vehicles In Urban Areas: Reducing Congestion, Emissions, Improving Accessibility, And Promoting Walking, Bicycling, And Use Of Public Transportation, Saravanan Venkatachalam, Ratna Babu Chinnam, Alper E. Murat Jan 2019

17-07 Phase-Ii: Community-Aware Charging Station Network Design For Electrified Vehicles In Urban Areas: Reducing Congestion, Emissions, Improving Accessibility, And Promoting Walking, Bicycling, And Use Of Public Transportation, Saravanan Venkatachalam, Ratna Babu Chinnam, Alper E. Murat

Transportation Research Center Reports

A major challenge for achieving large-scale adoption of EVs is an accessible infrastructure for the communities. The societal benefits of large-scale adoption of EVs cannot be realized without adequate deployment of publicly accessible charging stations due to mutual dependence of EV sales and public infrastructure deployment. Such infrastructure deployment also presents a number of unique opportunities for promoting livability while helping to reduce the negative side-effects of transportation (e.g., congestion, emissions, and noise pollution). In this phase, we develop a modeling framework (MF) to consider various factors and their associated uncertainties for an optimal network design for electrified vehicles. The …


Performance Test On Styrene-Butadiene-Styrene (Sbs) Modified Asphalt Based On The Different Evaluation Methods, Chen Zhang, Hainian Wang, Zhanping You, Junfeng Gao, Muhammad Irfan Jan 2019

Performance Test On Styrene-Butadiene-Styrene (Sbs) Modified Asphalt Based On The Different Evaluation Methods, Chen Zhang, Hainian Wang, Zhanping You, Junfeng Gao, Muhammad Irfan

Department of Civil, Environmental, and Geospatial Engineering Publications

To uniform the evaluation indicators of Styrene-Butadiene-Styrene (SBS) modified asphalt, the SK70# and SK90# matrix asphalt were modified by different SBS modifier dosage in this study. The test methods in China and Superpave were used to test the performance of each SBS-modified asphalt respectively, from which the appropriate evaluation index of SBS-modified asphalt was determined. The results showed that the addition of SBS modifier improved the high temperature performance and lowered the temperature sensitivity of asphalt binder, while it increased the viscosity of asphalt binder in high temperatures. Due to the variability that appeared in the results of the penetration …


Optimization Of The Calcium Alginate Capsules For Self-Healing Asphalt, Shi Xu, Amir Tabakovic, Xueyan Liu, Damian Palin, Erik Schlangen Jan 2019

Optimization Of The Calcium Alginate Capsules For Self-Healing Asphalt, Shi Xu, Amir Tabakovic, Xueyan Liu, Damian Palin, Erik Schlangen

Research and Innovation - Articles

Featured Application: This self-healing technology for asphalt pavements has the potential to greatly disrupt asphalt production methods (which have been stable over the past 100 years).This paper presents a development process of ‘calcium-alginate microcapsules encapsulating an asphalt bitumen rejuvenator’. The encapsulated rejuvenator is released when required (on demand) which rejuvenates the aged binder. Once crack is initiated and starts propagating it encounters a microcapsule, energy at tip of the crack opens the microcapsule, releasing the rejuvenator (healing agent). The rejuvenator will infuse into the aged binder soften it, allowing to flow, two broken edges to get into a contact and …


Low-Density Static Granular Media Filter Bed Turbidity Removal Model, Matthew Louque Jan 2019

Low-Density Static Granular Media Filter Bed Turbidity Removal Model, Matthew Louque

LSU Master's Theses

The scattering of light within a fluid, referred to as its turbidity, was investigated against the presence of suspended solids. A linear regression analysis was conduced against turbidity and the total count, combined surface area, and combined volume of the suspended particles for various surface water sources (lakes, rivers, indoor aquaculture systems). It was found that the total combined surface area of suspended particles had the best linear correlation to turbidity, with an adjusted R2 of 81.79%. This correlation was integrated with a current theoretical model for predicting solids removal across a granular bed to yield an Integrated Turbidity …


Long-Term Durability Of Frp Bond In The Midwest United States For Externally-Strengthened Bridge Components, Sasan Siavashi, Christopher D. Eamon, Abdel A. Makkawy, Hwai-Chung Wu Jan 2019

Long-Term Durability Of Frp Bond In The Midwest United States For Externally-Strengthened Bridge Components, Sasan Siavashi, Christopher D. Eamon, Abdel A. Makkawy, Hwai-Chung Wu

Civil and Environmental Engineering Faculty Research Publications

In this study, the bond strength of a typical FRP system subjected to long-term natural weathering in the Midwest United States is experimentally investigated, and the rate of degradation is estimated. To do this, the bond strength of an FRP system exposed to over fifteen years of weathering is determined with pull-off testing, and a relationship between strength reduction and exposure time is developed using regression analysis. For unweathered specimens, it was found that the attachment strength of the FRP system was governed by the concrete substrate, while for weathered specimens, the FRP system could detach by either a failure …


Webinar: Modeling Freeway Traffic In A Mixed Environment: Connected And Human-Driven Vehicles, Xianfeng Terry Yang Jan 2019

Webinar: Modeling Freeway Traffic In A Mixed Environment: Connected And Human-Driven Vehicles, Xianfeng Terry Yang

TREC Webinar Series

Although connected vehicles (CVs) will soon go beyond testbeds, CVs and human-driven vehicles (HVs) will co-exist over a long period. Hence, it is critical to consider the interactions between these two types of vehicles in traffic flow modeling. In this study, we aim to develop a macroscopic model to understand how CVs would impact HVs in the traffic stream. Grounded on the second-order traffic flow model, we study the relationships among flow, density, and speed by two sets of formulations for the groups of CVs and HVs, respectively. A set of friction factors, which indicate CVs' impact to HVs, are …


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 Jan 2019

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 …


Observational Time Series For Lakes Azuei And Enriquillo: Surface Area, Volume, And Elevation, Mahrokh Moknatian, Michael Piasecki Jan 2019

Observational Time Series For Lakes Azuei And Enriquillo: Surface Area, Volume, And Elevation, Mahrokh Moknatian, Michael Piasecki

Publications and Research

In this report, we present historical time series of surface area, volume, and elevation for lakes Azuei (Haiti) and Enriquillo (Dominican Republic). The intention is to present a history of the lakes’ levels for both bodies of water as derived from Landsat imagery that is augmented by reports and narratives that reach further back in time. We also summarize lake level time series data collected and developed through various other efforts and compare these data sets to our time series. The time series contains 45 years’ worth of data ranging from 1972 to 2017 which we developed from Landsat imagery …


Modeling Of Leakage Through Fault-Zone Structures In Co2 Geological Storage, Dayna Rodriguez Zambrano Jan 2019

Modeling Of Leakage Through Fault-Zone Structures In Co2 Geological Storage, Dayna Rodriguez Zambrano

LSU Master's Theses

Faults intersecting target geological CO2 storage zones have important implications for storage integrity. Potential leakage pathways due to fluid over-pressurization are investigated in this project to ensure long-term containment of injected CO2. Numerical flow simulations coupled with a geomechanical module are presented in this work with the purpose of determining the extent of CO2 up-fault migration, the driving mechanisms of leakage and the corresponding response of quantified pore pressure and stress variations.

This study uses dual-continuum models performed by using CMG (2017) to correctly account of flow through fractures in a fault damage zone. Numerical simulations …


Mechanical Vibration For The Control Of Membrane Fouling In Direct Contact Membrane Distillation, Frank Y.C. Huang, Carolyn Medin, Allie Arning Jan 2019

Mechanical Vibration For The Control Of Membrane Fouling In Direct Contact Membrane Distillation, Frank Y.C. Huang, Carolyn Medin, Allie Arning

Department of Civil, Environmental, and Geospatial Engineering Publications

One of the biggest challenges for direct contact membrane distillation (DCMD) in treating wastewater from flue gas desulfurization (FGD) is the rapid deterioration of membrane performance resulting from precipitate fouling. Chemical pretreatment, such as lime-soda ash softening, has been used to mitigate the issue, however, with significant operating costs. In this study, mechanical vibration of 42.5 Hz was applied to lab-scale DCMD systems to determine its effectiveness of fouling control for simulated FGD water. Liquid entry pressure and mass transfer limit of the fabricated hollow fiber membranes were determined and used as the operational constraints in the fouling experiments so …


Assessing Landscape Scale Heterogeneity In Irrigation Water Use With Remote Sensing And In Situ Monitoring, T. Foster, I. Z. Goncalves, I. Campos, C. M.U. Neale, N. Brozovic Jan 2019

Assessing Landscape Scale Heterogeneity In Irrigation Water Use With Remote Sensing And In Situ Monitoring, T. Foster, I. Z. Goncalves, I. Campos, C. M.U. Neale, N. Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Understanding how irrigation is used across agricultural landscapes is essential to support efforts to grow more food while reducing pressures on limited freshwater resources. However, to date, few studies have analyzed the underlying spatial and temporal variability in farmers’ individual water use decisions at a landscape scale.Wecompare estimates of irrigation water requirements derived using state-of-the-art remote sensing models with metered abstraction records for 1400 fields over a 13 year period in the US state of Nebraska, one of the world’s most intensively irrigated agricultural regions. Weshow that farmers’ observed water use decisions often diverge significantly from biophysical estimates of crop …


Sea Level Rise And Land Subsidence In Coastal Louisiana: Forecasting, Mapping And Identification Of At-Risk Transportation Infrastructure, Sanjay Tewari, Francis Manning, Wesley Palmer Jan 2019

Sea Level Rise And Land Subsidence In Coastal Louisiana: Forecasting, Mapping And Identification Of At-Risk Transportation Infrastructure, Sanjay Tewari, Francis Manning, Wesley Palmer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The coast of Louisiana is under threat because of sea level rise and land subsidence. Sea water is encroaching deeper inland and as a result Louisiana is losing land at an alarming rate. The combined effect of sea level rise and land subsidence is variable spatially. This paper focuses on this combined effect in identifying the transportation infrastructure that is at risk of getting affected by the seawater inundation of the land.

This paper attempts to account for land elevation data monitored continuously at various locations along the coast of Louisiana and combining it with local sea level rise to …


Pedestrian Safety -- Fundamental To A Walkable City, Joshua Herrera, Patrick Mcdevitt, Preeti Swaminathan, Raghuram Srinivas Jan 2019

Pedestrian Safety -- Fundamental To A Walkable City, Joshua Herrera, Patrick Mcdevitt, Preeti Swaminathan, Raghuram Srinivas

SMU Data Science Review

In this paper, we present a method to identify urban areas with a higher likelihood of pedestrian safety related events. Pedestrian safety related events are pedestrian-vehicle interactions that result in fatalities, injuries, accidents without injury, or near--misses between pedestrians and vehicles. To develop a solution to this problem of identifying likely event locations, we assemble data, primarily from the City of Cincinnati and Hamilton County, that include safety reports from a five year period, geographic information for these events, citizen survey of pedestrian reported concerns, non-emergency requests for service for any cause in the city, property values and public transportation …


From Drought To Food-Energy-Water-Security Nexus: An Assessment Of Food Insecurity In The Middle East, Maysoun Ayad Hameed Jan 2019

From Drought To Food-Energy-Water-Security Nexus: An Assessment Of Food Insecurity In The Middle East, Maysoun Ayad Hameed

Dissertations and Theses

Drought is an extreme climate phenomenon that happens slowly and periodically threatens the environmental and socio-economic sectors. Developing countries have experienced crucial conditions in meeting the needs for food, energy, and water security. Natural disasters contribute as risky sources of food insecurity and vulnerability in the Middle East. This dissertation presents a country-level review and quantitative assessment of the current issues associated with the Food-Energy-Water-Security (FEWS) Nexus in the Middle East. In this study, sixteen countries in the Middle East are chosen, namely, Arabian Peninsula, Iran, Syria, Lebanon, Israel, Palestine, Egypt, and Turkey. The most recent datasets are used to …


An Airlifted Tidal Mesocosm For Oil Degradation Studies, Daniel Christopher Alt Jan 2019

An Airlifted Tidal Mesocosm For Oil Degradation Studies, Daniel Christopher Alt

LSU Doctoral Dissertations

Mesocosms were constructed to allow scientists to isolate variables in a microtidal marsh environment, mimicking the natural conditions found in Terrebonne Bay. The control offered by these mesocosms is given by a process control system that takes user inputs and automates water movement. Twelve mesocosms were constructed, each holding 4.02 m3 (142 ft3) of marsh soil and 3.88 m3 (137 ft3) of water to give 3 experimental levels and a control, all in triplicate.

Each mesocosms that was constructed contained marsh plants in soil plugs 9 feet in diameter and 3 feet deep. These …


Experiment Study Of Lateral Unloading Stress Path And Excess Pore Water Pressure On Creep Behavior Of Soft Soil, Wei Huang, Kejun Wen, Dongsheng Li, Xiaojia Deng, Lin Li, Haifei Jiang, Farshad Amini Jan 2019

Experiment Study Of Lateral Unloading Stress Path And Excess Pore Water Pressure On Creep Behavior Of Soft Soil, Wei Huang, Kejun Wen, Dongsheng Li, Xiaojia Deng, Lin Li, Haifei Jiang, Farshad Amini

Civil and Architectural Engineering Faculty Research

The unloading creep behavior of soft soil under lateral unloading stress path and excess pore water pressure is the core problem of time-dependent analysis of surrounding rock deformation under excavation of soft soil. The soft soil in Shenzhen, China, was selected in this study. The triaxial unloading creep tests of soft soil under different initial excess pore water pressures (0, 20, 40, and 60 kPa) were conducted with the K0 consolidation and lateral unloading stress paths. The results show that the unloading creep of soft soil was divided into three stages: attenuation creep, constant velocity creep, and accelerated creep. The …


Design And Evaluation Of Iot-Enabled Instrumentation For A Soil-Bentonite Slurry Trench Cutoff Wall, Jeffrey C. Evans, Alan Marchiori, Yadong Li Jan 2019

Design And Evaluation Of Iot-Enabled Instrumentation For A Soil-Bentonite Slurry Trench Cutoff Wall, Jeffrey C. Evans, Alan Marchiori, Yadong Li

Faculty Journal Articles

In this work, we describe our approach and experiences bringing an instrumented soil-bentonite slurry trench cutoff wall into a modern IoT data collection and visualization pipeline. Soil-bentonite slurry trench cutoff walls have long been used to control ground water flow and contaminant transport. A Raspberry Pi computer on site periodically downloads the sensor data over a serial interface from an industrial datalogger and transmits the data wirelessly to a gateway computer located 1.3 km away using a reliable transmission protocol. The resulting time-series data is stored in a MongoDB database and data is visualized in real-time by a custom web …


Near-Field Mean Flow Dynamics Of A Cylindrical Canopy Patch Suspended In Deep Water, Jian Zhou, Subhas K. Venayagamoorthy Jan 2019

Near-Field Mean Flow Dynamics Of A Cylindrical Canopy Patch Suspended In Deep Water, Jian Zhou, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The time-averaged flow dynamics of a suspended cylindrical canopy patch with a bulk diameter of D is investigated using large-eddy simulations (LES). The patch consists of Nc constituent solid circular cylinders of height h and diameter d, mimicking patchy vegetation suspended in deep water (H/h ≫ 1, where H is the total flow depth). After validation against published data, LES of a uniform incident flow impinging on the canopy patch was conducted to study the effects of canopy density (0.16 ≤ φ = Nc(d/D)2 ≤ 1, by varying Nc) and bulk aspect ratio (0.25 ≤ AR = h/D ≤ …


Failure Mode Identification Of Masonry Infilled Rc Frames, Rabab Allouzi, Ayhan Irfanoglu Jan 2019

Failure Mode Identification Of Masonry Infilled Rc Frames, Rabab Allouzi, Ayhan Irfanoglu

Emirates Journal for Engineering Research

This paper presents a new method to identify the ultimate failure mode of reinforced concrete (RC) frames due to the presence of masonry infill walls. The proposed method is based on simple geometry, reinforcement ratios and material properties of the elements involved in the frame-wall assembly. A simple engineering tool, expressed in terms of infill wall-to-RC frame stiffness and strength ratios, is developed to estimate whether the ultimate failure mode that would evolve during strong earthquake ground shaking in the infilled RC frame is brittle or ductile. The brittle failure mode, that is, shear failure in columns, should be avoided …