Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Nebraska - Lincoln (11)
- University of Dar es Salaam (10)
- Missouri University of Science and Technology (9)
- University of Arkansas, Fayetteville (7)
- Technological University Dublin (5)
-
- California Polytechnic State University, San Luis Obispo (3)
- City University of New York (CUNY) (3)
- University of Dayton (3)
- Chapman University (2)
- Clemson University (2)
- LSU New Orleans (2)
- Linfield University (2)
- Purdue University (2)
- University of New Hampshire (2)
- University of New Mexico (2)
- Association of Arab Universities (1)
- Beirut Arab University (1)
- Bucknell University (1)
- Department of Primary Industries and Regional Development, Western Australia (1)
- Embry-Riddle Aeronautical University (1)
- Georgia Southern University (1)
- Louisiana State University (1)
- Old Dominion University (1)
- Southern Methodist University (1)
- Tashkent State Technical University (1)
- The British University in Egypt (1)
- The University of Akron (1)
- Universitas Indonesia (1)
- University of Kentucky (1)
- University of Montana (1)
- Keyword
-
- Earthquakes (3)
- Nuclear magnetic resonance (3)
- Relaxometry (3)
- Sustainability (3)
- Thermography (3)
-
- Aggregate (2)
- Asphalt aging (2)
- Asphalt binder (2)
- Bridge (2)
- Climate Change (2)
- Concrete (2)
- Concrete delamination (2)
- Design (2)
- Geophysics (2)
- Hot mix asphalt (2)
- Insulation (2)
- Modeling (2)
- Nondestructive evaluation (2)
- Physics (2)
- Precariously balanced rocks (2)
- Project Management (2)
- Retrofit (2)
- Rocking (2)
- Seismic Resilience (2)
- Sliding (2)
- ANTI VIRUSES (1)
- Acoustic resonance (1)
- Adaptive Resonance Theory (1)
- Aerodynamic forces (1)
- Aging of fiber-reinforced polymer composites (1)
- Publication Year
- Publication
-
- Tanzania Journal of Engineering and Technology (TJET) (10)
- Civil, Architectural and Environmental Engineering Faculty Research & Creative Works (7)
- Graduate Theses and Dissertations (6)
- Articles (4)
- Department of Construction Engineering and Management: Faculty Publications (4)
-
- Civil and Environmental Engineering and Engineering Mechanics Faculty Publications (3)
- Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research (3)
- Business and Information Technology Faculty Research & Creative Works (2)
- Department of Civil and Environmental Engineering: Faculty Publications (2)
- Faculty Publications (2)
- LSU New Orleans Theses and Dissertations (2)
- Mathematics, Physics, and Computer Science Faculty Articles and Research (2)
- Publications and Research (2)
- Senior Theses (2)
- All Dissertations (1)
- All Theses (1)
- Architectural Engineering (1)
- BAU Journal - Science and Technology (1)
- Branch Mathematics and Statistics Faculty and Staff Publications (1)
- Browse all Datasets (1)
- Chemical Technology, Control and Management (1)
- Civil Engineering (1)
- Civil and Environmental Engineering Theses and Dissertations (1)
- College of Engineering Summer Undergraduate Research Program (1)
- College of Graduate Studies: Theses & Dissertations (1)
- Computer Information Technology Faculty Publications (1)
- Datasets (1)
- Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023– (1)
- Dissertations and Theses (1)
- Doctoral Dissertations and Master's Theses (1)
- Publication Type
- File Type
Articles 31 - 60 of 86
Full-Text Articles in Structural Engineering
Analyzing Ground Motion Records With Cvi Fuzzy Art, Dustin Tanksley, Xinzhe Yuan, Genda Chen, Donald C. Wunsch
Analyzing Ground Motion Records With Cvi Fuzzy Art, Dustin Tanksley, Xinzhe Yuan, Genda Chen, Donald C. Wunsch
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper explores using Cluster Validity Indices Fuzzy Adaptative Resonance Theory (CVI Fuzzy ART) to cluster ground motion records (GMRs). Clustering the features extracted from a supervised network trained for predicting the structure damage results in less overfitting from the trained network. Using Cluster Validity Indices (CVIs) to evaluate the clustering gives feedback to how well the data is being classified, allowing further separation of the data. By using CVI Fuzzy ART in combination with features extracted from a trained Convolutional Neural Network (CNN), we were able to form additional clusters in the data. Within the primary clusters, accuracy was …
The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr.
The Living Breakwaters Pdr Efforts: Conceptual Scheduling, Calvin O. Walters Jr.
Publications and Research
On October 29, 2012, Superstorm Sandy caused nearly $19 billion in damages in New York City including 69,000 residential units across the five boroughs. This disaster precipitated a post-disaster-rebuilding (PDR) project including roughly $4.2 billion in a Community Development Block Grant allocated towards PDR projects. A portion of the grant was used to construct a living breakwater in Tottenville, Staten Island, consisting of a resiliency approach to risk reduction through erosion prevention, wave energy attenuation, and enhancement of ecosystems and social resiliency to improve resistance to storms for the community of Tottenville. The ridges of each breakwater are designed with …
Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi
Resilient Modulus Of Siliciclastic Unbound Granular Materials Under Repeated Wheel Loading, Siya Rimoyi
Tanzania Journal of Engineering and Technology (TJET)
The Resilient Modulus (Mr) is a fundamental material property input in modern Mechanistic-Empirical (M-E) pavements structural design. Empirical pavement design methods have been in use over a long period during which large databases of four- days-soaked California Bearing Ratio (CBR) values at or near the Maximum Dry Density have been generated in the strength assessments for Unbound Granular Materials (UGMs). In the adoption of the M-E design approach researchers have so far attempted with various degrees of success to develop models to derive resilient modulus from the conventional CBR-based databases. This study provides an extensive laboratory experimental study to investigate …
Assessing The Vertical Displacement Of The Grand Ethiopian Renaissance Dam During Its Filling Using Dinsar Technology And Its Potential Acute Consequences On The Downstream Countries, Hesham El-Askary, Amr Fawzy, Rejoice Thomas, Wenzhao Li, Nicholas Lahaye, Erik Linstead, Thomas Piechota, Daniele Struppa, Mohamed Abdelaty Sayed
Assessing The Vertical Displacement Of The Grand Ethiopian Renaissance Dam During Its Filling Using Dinsar Technology And Its Potential Acute Consequences On The Downstream Countries, Hesham El-Askary, Amr Fawzy, Rejoice Thomas, Wenzhao Li, Nicholas Lahaye, Erik Linstead, Thomas Piechota, Daniele Struppa, Mohamed Abdelaty Sayed
Mathematics, Physics, and Computer Science Faculty Articles and Research
The Grand Ethiopian Renaissance Dam (GERD), formerly known as the Millennium Dam, is currently under construction and has been filling at a fast rate without sufficient known analysis on possible impacts on the body of the structure. The filling of GERD not only has an impact on the Blue Nile Basin hydrology, water storage and flow but also poses massive risks in case of collapse. Rosaries Dam located in Sudan at only 116 km downstream of GERD, along with the 20 million Sudanese benefiting from that dam, would be seriously threatened in case of the collapse of GERD. In this …
A Novel Probabilistic Framework Of Rc Corroded Structures Under Dynamic Loading, Rawan Mouin Mashmoushy Eng., Wael Slika, Adel Elkordi
A Novel Probabilistic Framework Of Rc Corroded Structures Under Dynamic Loading, Rawan Mouin Mashmoushy Eng., Wael Slika, Adel Elkordi
BAU Journal - Science and Technology
Steel corrosion in reinforced concrete structures can lead to severe deterioration damage under static and seismic loads. In practice, it is essential to mitigate failure risk by quantifying the extent of damage and simulating the structural response of damaged structures. However, numerical modeling of the dynamic behavior of corroded structure is challenging due to high nonlinearity of the problem and its multidisciplinary nature. In addition, corrosion damage exhibits various sources of uncertainty that impede accurate deterministic modeling of the dynamic response of RC structures. Therefore, this study presents a simplified framework, to simulate the non-linear response of corroded structures under …
Computational Design Of Nonlinear Stress-Strain Of Isotropic Materials, Askhad M.Polatov, Akhmat M. Ikramov, Daniyarbek Razmukhamedov
Computational Design Of Nonlinear Stress-Strain Of Isotropic Materials, Askhad M.Polatov, Akhmat M. Ikramov, Daniyarbek Razmukhamedov
Chemical Technology, Control and Management
The article deals with the problems of numerical modeling of nonlinear physical processes of the stress-strain state of structural elements. An elastoplastic medium of a homogeneous solid material is investigated. The results of computational experiments on the study of the process of physically nonlinear deformation of isotropic elements of three-dimensional structures with a system of one- and double-periodic spherical cavities under uniaxial compression are presented. The influence and mutual influence of stress concentrators in the form of spherical cavities, vertically located two cavities and a horizontally located system of two cavities on the deformation of the structure are investigated. Numerical …
Improving Logistics Efficiency Through Collaborative Truck Routing, Patrick Dougherty
Improving Logistics Efficiency Through Collaborative Truck Routing, Patrick Dougherty
Industrial Engineering Undergraduate Honors Theses
The logistics industry is among the world’s largest and most essential. Specifically, trucking is a massive component of the modern logistics system. In 2012, truck transportation carried 68% of all freight tonnage in the U.S. However, trucking currently faces significant problems with efficiency and sustainability. Of all miles driven by trucks yearly in the U.S., 25% are driven with empty loads and 36% are driven with underutilized loads. In addition to this economic inefficiency, the industry faces social and environmental challenges. Driver turnover rates are near 100%, and trucking accounts for a significant level of greenhouse gas emissions. One potential …
Workshop Outcomes Report: 1st International Workshop On Seismic Resilience Of Arctic Infrastructure And Social Systems, Majid Ghayoomi, Katharine Duderstadt, Alexander Kholodov, Alexander Shiklomanov, Matthew Turner, Elham Ajorlou
Workshop Outcomes Report: 1st International Workshop On Seismic Resilience Of Arctic Infrastructure And Social Systems, Majid Ghayoomi, Katharine Duderstadt, Alexander Kholodov, Alexander Shiklomanov, Matthew Turner, Elham Ajorlou
Faculty Publications
No abstract provided.
Artificial Intelligence And Soft Computing In Smart Structural Systems, Sajad Javadinasab Hormozabad
Artificial Intelligence And Soft Computing In Smart Structural Systems, Sajad Javadinasab Hormozabad
Theses and Dissertations--Civil Engineering
Next-generation smart cities are the key feature in the next chapter of human life. Cities that employ innovative and technology-driven solutions to improve the sustainability, resilience, prosperity, and amenity of the community are considered smart cities. Development of smart cities requires fundamental innovations in many technical and technological aspects including those contributing to smart structures. Smart technologies improve the structural performance against natural disasters like earthquakes, hurricanes, tornados, and promote the sustainability of structural systems. Next-generation smart structures encompass a variety of technologies including Structural Control (SC) and Structural Health Monitoring (SHM). SC covers methodologies and technologies that modify the …
Optimisation Of Retrofit Wall Insulation: An Irish Case Study, Rakshit D. Muddu, D M. Gowda, Anthony James Robinson, Aimee Byrne
Optimisation Of Retrofit Wall Insulation: An Irish Case Study, Rakshit D. Muddu, D M. Gowda, Anthony James Robinson, Aimee Byrne
Articles
Ireland has one of the highest rates of emissions per capita in the world and its residential sector is responsible for approximately 10% of total national CO2 emissions. Therefore, reducing the CO2 emissions in this sector will play a decisive role in achieving EU targets of reducing emissions by 40% by 2030. To better inform decisions regarding retrofit of the existing building stock, this study proposes Optimum Insulation Thicknesses (OIT) for typical walls in 25 regions in Ireland. The calculation of OIT includes annual heat energy expenditure, CO2 emissions, and material payback period. The approach taken is based on Heating …
Seismic Loading Effects Within Orthogonally Connected Steel Lateral Force Resisting Systems, Alhussin Faraj Aliwan
Seismic Loading Effects Within Orthogonally Connected Steel Lateral Force Resisting Systems, Alhussin Faraj Aliwan
Graduate Theses and Dissertations
Steel buildings located within seismically active regions require special design considerations to ensure public safety and prevent collapse during an extreme seismic event. Two commonly used steel systems are special moment frames (SMFs) and buckling-restrained braced frames (BRBFs). When two seismic systems share a common column in an orthogonal configuration (such as at a building corner), design specifications currently consider a 100+30 rule wherein the shared column is designed for 100% fuse demand in one direction, plus 30% fuse demand from the other direction. While this rule has been shown to be reasonable for elastic building response, a few studies …
Deep Learning Techniques For Structural Response Prediction During Strong Ground Motions, Ahmed A. Torky, Susumu Ohno Prof., Toshide Kashima Prof.
Deep Learning Techniques For Structural Response Prediction During Strong Ground Motions, Ahmed A. Torky, Susumu Ohno Prof., Toshide Kashima Prof.
Civil Engineering
In this paper, deep learning techniques are applied to predict a building’s structural response to strong ground motions. Data from sensors near and inside structures measure accelerations during strong ground motions. The Building Research Institute (BRI) ANX building, an eight-story structure, has experienced major earthquakes since 1998. Sensors in the building provide and accumulate big data of historic events. Changes of the natural frequency of the ANX building from the big data is initially quantified. The time-series data of the historic events can be used to predict future response to future events using deep learning models rapidly. Although previous literature …
Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen
Automatic Delamination Segmentation For Bridge Deck Based On Encoder-Decoder Deep Learning Through Uav-Based Thermography, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen
Department of Construction Engineering and Management: Faculty Publications
Concrete deck delamination often demonstrates strong variations in size, shape, and temperature distribution under the influences of outdoor weather conditions. The strong variations create challenges for pure analytical solutions in infrared image segmentation of delaminated areas. The recently developed supervised deep learning approach demonstrated the potentials in achieving automatic segmentation of RGB images. However, its effectiveness in segmenting thermal images remains under-explored. The main challenge lies in the development of specific models and the generation of a large range of labeled infrared images for training. To address this challenge, a customized deep learning model based on encoder-decoder architecture is proposed …
On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez
On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez
Graduate Theses and Dissertations
Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …
Macro - And Microstructure Evaluation And Field Applications Of Concrete With Recycled Glass Pozzolan, Marija Krstic
Macro - And Microstructure Evaluation And Field Applications Of Concrete With Recycled Glass Pozzolan, Marija Krstic
Dissertations and Theses
Concrete is the most used material in the world, second only to water. Conventional concrete is produced with Portland cement (PC). The production of cement is an energy intensive operation that has raised significant environmental concerns, since one ton of cement generates an equal ton of CO2. In the USA about 90 million tons of cement are used annually, with 3 million tons used in New York. Most contemporary concrete applications for buildings and infrastructure use high-performance concrete (HPC) mixtures which are produced by replacing a percentage of cement with supplementary cementitious materials (SCMs), consisting mainly of fly-ash …
Time-Dependent Reliability Framework For Durability Design Of Frp Composites, Rajneesh Kumar Bharil
Time-Dependent Reliability Framework For Durability Design Of Frp Composites, Rajneesh Kumar Bharil
Graduate Theses, Dissertations, and Problem Reports (ETD)
The life-cycle performance, durability, and aging characteristics of Fiber Reinforced Polymer (FRP or Structural Composites) have been of keen interest to the engineers engaged in the FRP design, construction, and manufacturing. Unlike conventional construction materials such as steel and concrete, the design guidelines to account for the aging of FRP are somewhat scattered or not available in an approved or consistent format. Loss of strength over time or aging of any structural material should be of concern to engineers as the in-service lifespan of many engineering structures is expected to exceed 100 years. Use of durability strength-reduction factors or factors …
The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1
The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1
Tanzania Journal of Engineering and Technology (TJET)
Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …
Incorporating Geophysical Data In Slope Stability Modeling For Two Slopes In Arkansas, Vanessa Lebow
Incorporating Geophysical Data In Slope Stability Modeling For Two Slopes In Arkansas, Vanessa Lebow
Graduate Theses and Dissertations
Slope failures in the United States alone cause millions of dollars in damage to infrastructure, threaten national monuments, create environmental hazards, and take an average of 25-50 lives a year. With the inevitable construction that occurs on slopes, it is imperative that the slopes be properly designed which requires a thorough understanding of slope grade, subsurface soil conditions, soil strength parameters, water table locations, and depth to bedrock across the entire site. The preferred method of data collection would be to use borings and other in-situ methods; however, sometimes due to cost constraints or site accessibility only a very limited …
The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen
The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen
Department of Construction Engineering and Management: Faculty Publications
Conventional nondestructive delamination detection of concrete pavements through thermography is often based on temperature contrasts between delaminated and sound areas. Non-uniform backgrounds caused by the environmental conditions are often challenging for contrast-based methods to robustly differentiate the delaminated areas from the sound areas. Instead of focusing on the temperature contrast, this study proposes a temperature gradient-based level set method (LSM) to detect boundaries for delamination segmentations. A modified edge indicator function is developed to represent the normalized temperature gradient of a thermal image. The experimental study was conducted to evaluate its applicability and stability for boundary detection in terms of …
Probabilistic Analysis Of Slide-Rocking Structures Under Earthquake Loads, Taylor J. Knickerbocker
Probabilistic Analysis Of Slide-Rocking Structures Under Earthquake Loads, Taylor J. Knickerbocker
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Estimates of rare seismic hazard are essential for the resilience of critical infrastructure and facilities. However, these estimates are highly uncertain at long return periods due to the lack of observed earthquake records. Several ground motion prediction equations have been proposed to close this gap and estimate rare seismic demands; however, these models were developed based on more moderate earthquake records and can yield physically unrealizable ground motions when extrapolated to long return periods. For this reason, seismologists have proposed using precariously balanced rocks (PBRs) as a way to constrain rare seismic hazard. PBRs are a type of fragile geologic …
Detection Of Sand Boils From Images Using Machine Learning Approaches, Aditi S. Kuchi
Detection Of Sand Boils From Images Using Machine Learning Approaches, Aditi S. Kuchi
LSU New Orleans Theses and Dissertations
Levees provide protection for vast amounts of commercial and residential properties. However, these structures degrade over time, due to the impact of severe weather, sand boils, subsidence of land, seepage, etc. In this research, we focus on detecting sand boils. Sand boils occur when water under pressure wells up to the surface through a bed of sand. These make levees especially vulnerable. Object detection is a good approach to confirm the presence of sand boils from satellite or drone imagery, which can be utilized to assist in the automated levee monitoring methodology. Since sand boils have distinct features, applying object …
Urban Underground Infrastructure Monitoring Iot: The Path Loss Analysis, Abdul Salam, Syed Shah
Urban Underground Infrastructure Monitoring Iot: The Path Loss Analysis, Abdul Salam, Syed Shah
Computer Information Technology Faculty Publications
The extra quantities of wastewater entering the pipes can cause backups that result in sanitary sewer overflows. Urban underground infrastructure monitoring is important for controlling the flow of extraneous water into the pipelines. By combining the wireless underground communications and sensor solutions, the urban underground IoT applications such as real time wastewater and storm water overflow monitoring can be developed. In this paper, the path loss analysis of wireless underground communications in urban underground IoT for wastewater monitoring has been presented. It has been shown that the communication range of up to 4 kilometers can be achieved from an underground …
Bridge Deck Delamination Segmentation Based On Aerial Thermography Through Regularized Grayscale Morphological Reconstruction And Gradient Statistics, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen
Bridge Deck Delamination Segmentation Based On Aerial Thermography Through Regularized Grayscale Morphological Reconstruction And Gradient Statistics, Chongsheng Cheng, Zhexiong Shang, Zhigang Shen
Department of Construction Engineering and Management: Faculty Publications
Environmental and surface texture-induced temperature variation across the bridge deck is a major source of errors in delamination detection through thermography. This type of external noise poises a significant challenge for conventional quantitative methods such as global thresholding and k-means clustering. An iterative top-down approach is proposed for delamination segmentation based on grayscale morphological reconstruction. A weight-decay function was used to regularize the reconstruction for regional maxima extraction. The mean and coefficient of variation of temperature gradient estimated from delamination boundaries were used for discrimination. The proposed approach was tested on a lab experiment and an in-service bridge deck. The …
Development Of Poly-Vinyl Alcohol Stabilized Silver Nanofluids For Solar Thermal Applications, James Walshe, George Amarandei, Hind Ahmed, Sarah Mccormack, John Doran
Development Of Poly-Vinyl Alcohol Stabilized Silver Nanofluids For Solar Thermal Applications, James Walshe, George Amarandei, Hind Ahmed, Sarah Mccormack, John Doran
Articles
Nanofluids offer the potential to address the low thermal conductivities found in conventional heat transfer fluids, through their unique electrical, optical and thermal properties, but their implementation remains restricted due to absorption and stability limitations. Here, we characterize and exploit the distinctive plasmonic properties exhibited by polyvinyl-alcohol stabilized silver nanostructures by tuning their absorption and thermal properties through controlling the nanoparticle size, morphology and particle-size distribution configuration at the synthesis stage. The photo-thermal efficiency of different water-based silver nanofluids under a standard AM1.5G weighted solar spectrum were explored, the influence of each of these components on the resulting fluids performance …
Efficient Intensity Measures Of Slide-Rocking Structures For Precariously Balanced Rocks, Taylor J. Knickerbocker, Christine E. Wittich
Efficient Intensity Measures Of Slide-Rocking Structures For Precariously Balanced Rocks, Taylor J. Knickerbocker, Christine E. Wittich
Department of Civil and Environmental Engineering: Faculty Publications
Precariously balanced rocks (PBRs) and other fragile geologic features are important in both the engineering and seismological communities since they are indicative of the maximum ground motion at a site over the rock’s lifetime. Precariously balanced rocks are individual or stacks of freestanding rocks that tend to respond in rigid body modes when subject to seismic excitation – namely, rocking, sliding, slide-rocking, and free-flight, which can lead to overturning. The seismic response of freestanding structures, such as PBRs, is known to be extremely sensitive to small changes in geometry, position, and earthquake excitation. As such, deterministic methods are limited in …
Utilizing The Hvsr Second Peak For Surface Wave Inversions In The Mississippi Embayment, Ashraf Kamal Himel
Utilizing The Hvsr Second Peak For Surface Wave Inversions In The Mississippi Embayment, Ashraf Kamal Himel
Graduate Theses and Dissertations
Ambient noise data from 24 sites within the Mississippi Embayment were analyzed to estimate the fundamental frequency using the horizontal to vertical spectral ratio (HVSR) method. The fundamental frequency ranged from 0.17 to 3.43 Hz for the tested sites. At seventeen of the sites, a second higher frequency HVSR peak, which ranged from 0.617 Hz to 2.154 Hz, was observed in addition to the fundamental HVSR peak. The second peak frequency in the HVSR curve has been attributed by previous researchers as either an odd harmonic of the fundamental peak or a shallow impedance contrast from the Memphis sand layer …
Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti
Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti
Shared Knowledge Conference
Ultrasonic monitoring in cementitious materials is challenging due to the high degree of attenuation. In wellbore environments, monitoring becomes more challenging due to inaccessibility. Meta materials, also known as acoustic bandgap materials, exhibit an interesting feature of forbidding the propagation of elastic/sound waves and isolate vibration in a certain frequency band. Traditionally, acoustic bandgap materials are developed with inclusions such as tin, aluminum, gold, steel in a polymer matrix. In this study, we present the development of three-dimensional cementitious sensors capable of exhibiting stopbands in the acoustic transmission spectra using carbon nanotubes. Relatively wide stopbands were engineered using Floquet-Bloch periodic …
3-D Reconstructions And Numerical Simulations Of Precarious Rocks In Southern California, Christine E. Wittich, Tara C. Hutchinson, J. Desanto, D. Sandwell
3-D Reconstructions And Numerical Simulations Of Precarious Rocks In Southern California, Christine E. Wittich, Tara C. Hutchinson, J. Desanto, D. Sandwell
Department of Civil and Environmental Engineering: Faculty Publications
Reliable estimates of seismic hazard are essential for the development of resilient communities; however, estimates of rare, yet high intensity earthquakes are highly uncertain due to a lack of observations and recordings. Lacking this data, seismic hazard analyses may be based on extrapolations from earthquakes with more moderate return periods, which can lead to physically unrealistic earthquake scenarios. However, the existence of certain precariously balanced rocks (PBRs) has been identified as an indicator of an upper bound ground motion, which precludes toppling of the balanced rock, over its lifetime. To this end, a survey of PBRs was conducted in proximity …
Effects Of Tension On Resonant Frequencies Of Strings, Blake Burnett
Effects Of Tension On Resonant Frequencies Of Strings, Blake Burnett
Senior Theses
This project tests and explores resonance of strings. Since all materials and mechanisms are affected by vibrations, it is important to know the frequencies at which resonance occurs. To explore this subject, strings were used as a model material to test the effect tension has on resonance. The fundamental frequencies and the corresponding modes of resonance were used to analyze the data. The results of this experiment show that increasing tension on a string increases its resonance frequency. Understanding the physics behind resonance frequency allows systems to be designed to take advantage of resonance properties, or to avoid resonance where …
Liquefaction-Induced Dragload And/Or Downdrag On Deep Foundations Within The New Madrid Seismic Zone, Ishimwe Elvis
Liquefaction-Induced Dragload And/Or Downdrag On Deep Foundations Within The New Madrid Seismic Zone, Ishimwe Elvis
Graduate Theses and Dissertations
Deep foundation elements are typically used to transfer structural loads for multi-story buildings and large-span bridges to a competent soil layer when 1) the soil close to the ground surface has no sufficient bearing capacity, and when 2) liquefiable soils are encountered. The majority of the bridges constructed within seismic zones rely upon the stability of earthen embankments and deep foundation that are installed above or within liquefiable soil deposits. Despite large factor of safety values or different load and resistance factors being used to adequately design deep foundations within seismic areas, soil liquefaction may cause extensive damage to the …