Numerical Study Of Sediment Suspension Affected By Rigid Cylinders Under Unidirectional And Combined Wave-Current Flows, Sha Lou, Xiaolan Chen, Shengyu Zhou, Gangfeng Ma, Shuguang Liu, Larisa Dorzhievna Radnaeva, Elena Nikitina, Irina Viktorovna Fedorova

Civil & Environmental Engineering Faculty Publications

Sediment transport modeling for flows with cylinders is very challenging owing to the complicated flow–cylinder–sediment interactions, especially under the combined wave-current flows. In this paper, an improved formulation for incipient sediment suspension considering the effect of cylinder density (i.e., solid volume fraction) is employed to simulate the bottom sediment flux in the flow with cylinders. The proposed model is calibrated and validated using laboratory measurements under unidirectional and combined wave-current flows in previous studies. It is proved that the effects of cylinders on sediment suspension can be accounted for through a modified critical Shields number, and the proposed model is …

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an eort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Cascadia Subduction Zone Earthquake Vertical Ground Acceleration Investigation And Potential Impact On Bridges In The Pacific Northwest, Rachel C. Bassil

Civil and Environmental Engineering Master's Project Reports

The effects of vertical ground accelerations during subduction zone earthquakes currently are not sufficiently understood. There are numerous case studies and evidence that effects of vertical ground accelerations can significantly impact the performance of bridges during a seismic event, but most previous research has been focused on shallow crustal earthquakes. Current bridge design codes provide little guidance for accounting for vertical ground accelerations in seismic design, in part because additional information is needed about the characteristics of vertical ground motions during Cascadia Subduction Zone (CSZ) earthquakes in the Pacific Northwest.

For this study, recorded seismic data from recent subduction zone …

Erosion And Resuspension Of Cohesive Sediments In Coastal Louisiana, Laith Qasem Shamaileh

University of New Orleans Theses and Dissertations

The research presented in this study is motivated by the need to improve the predictions of cohesive sediment erosion and subsequent transport. In addition, the knowledge of the geotechnical engineering soil properties related to the erosion of sediments in coastal Louisiana has broad implications as these properties are used in transport models guiding the current restoration efforts. The erosion measuring device used in the study is the Cheng-Han Tasi and Wilbert Lick Shaker. Previous studies have been conducted before using the Shaker, but challenges with the calibration of the shear stress hampered the resuspension results produced by the Shaker. Therefore, …

Continuous Moisture Measurement During Pavement Foundation Construction: Laboratory Measurements, Isaac Esteban Zuniga

Open Access Theses & Dissertations

Moisture content directly affects all properties of subgrade materials. A rapid, continuous, and accurate technique to determine moisture content during subgrade construction is the next step needed to improve the mechanistic-based quality of pavement foundations. In this study, six geomaterials were compacted to standard/modified proctor specifications and subjected to laboratory measurements to study the variations in their electromagnetic and electric properties with moisture content. The relationships between the seismic modulus, unconfined compressive strength, lightweight deflectometer, and moisture content for the same geomaterials were also established. Large-scale replicate specimens were also compacted and subjected to numerous measurements. The dielectric constant measured …

Development Of An Excel Model To Evaluate The Stability Of Slopes, Bradley Davis

All Graduate Plan B and other Reports

This objective of this study is to determine a method or tool for taking given slope stability parameters and quickly and effectively determining the factor of safety against sliding of fully softened slopes. This study evaluates the effects of soil and geometric parameters of common slopes, and models these properties in a hypothetical model. The methodology is based on a parametric analysis using the Spencer’s Method of Slices limit equilibrium analysis used in the computer program Slide2. A parametric analysis is performed to determine which soil and/or geometric properties have a high influence on slope stability. The parametric analysis is …

Investigation Of Geopolymer Based Soil Stabilization Methods For Expedient Airfield Pavement Surfaces, Brett Albertson

All Theses

The United States Air Force (USAF) has the unique capability of being able to interdict superior airpower anywhere, at any time. However, superior airpower is only as effective as the amount of time an aircraft can spend in a particular area. The closer an aircraft can get to the mission need, the more time that can be spent in the air, or the less time that must be spent moving in and out of the operational area. Through the use of skilled and experienced men and women, the USAF is able to apply expedient and unsurfaced airfield paving techniques that …

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

Publications and Research

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

Geology-Based Shear-Wave Velocity Model Of Reference Site Conditions In South Carolina For Seismic Site Response Analysis, Camilius Amevorku

All Dissertations

Assessing earthquake hazard in the State of South Carolina is important because it is one of the most seismically active regions of the eastern United States and has experienced earthquakes of damaging levels in the historical past. Examples of these damaging seismic events are the 1886 Charleston earthquake (M 6.7 to 7.5) and the 1913 Union County earthquake (M 4.5 to 5.5).

Small-strain shear-wave velocity (V_S) is an important parameter in performing site response analysis. The deep nature of the top of reference firm rock (i.e., V_S ≥ 760 m/s or B-C boundary) due to …

Experimental Investigation Of Clay Aggregate And Granular Biofilm Behavior, Tao Jiang

Doctoral Dissertations

Clay minerals are a class of phyllosilicates as the major solid constituents in cohesive fine-grained soils (e.g., clays). Owing to their tiny size (i.e., < 2 μm), high aspect ratio, and active surface properties that inherit from the geological process, clay minerals can extensively interact with other suspended matter (e.g., exoployemers, microorganisms) and dissolved ions via the process of flocculation and aggregation, resulting in the formation of larger, porous cohesive particulate aggregates or flocs. Such a complex mechanism of microscale particle interaction generates significant challenges for understanding the bulk clay behavior as a particulate system. In order to better characterize the flocculation and aggregation of clay minerals under various stimuli and to understand the underlying mechanism of particle interactions, particle/aggregate size kinetics of flocculated suspensions of illite, a representative 2:1 clay mineral abundant in marine soils, are studied with varied ionic strength induced by monovalent salt (NaCl), pH, and hydrodynamic shearing in the first phase of this research. Furthermore, a new statistical data binning method termed “bin size index” (BSI) was employed to determine the probability density function (PDF) distributions of flocculated illite suspensions. The statistical results demonstrate that the size kinetics of flocculated illite suspensions is chiefly controlled by the face-to-face and edge-to-face interparticle interactions under the mutual effects of ionic strength and pH, while the hydrodynamic shearing has minimal effects on the variation of particle size groups.

In the second phase of this research, the mechanics of clay aggregates are studied using an innovative measurement technique and analytical approach. Individual clay minerals prepared with different mineralogy and salinities are tested via unconfined compression, which shows that the increasing ionic strength can improve the strength and stiffness of clay aggregates, which are further affected by the mineralogical compositions and dominant microfabric in different water chemistry.

In the final phase of this research, a collaborative …

Randomly Generating The 3d Mesostructure Of Soil Rock Mixtures Based On The Full In Situ Digital Image Processed Information, Zhengsheng Li, Haiyang Yi, Cheng Zhu, Zhuang Zhuo, Guoshuan Liu

Henry M. Rowan College of Engineering Faculty Scholarship

Understanding the occurrence and evolution of geological disasters, such as landslides and debris flows, is facilitated by research on the performance of soil rock mixes (SRM). Recently, more and more researchers have been interested in studying the mesostructure reconstruction process of SRM. The present mesostructure generation approaches, however, have several weaknesses. One of the weaknesses is that they do not consider the impact of particle shape and therefore cannot ensure similarity to the in situ SRMs. In this study, a new mesostructure generation method that randomly generates SRMs based on the full in situ digital image processing (DIP) information is …

Analysis Of Behaviour Of T Junctions By Varying Angles And Type Of Flow., Rhitam Chakroborty, A.R. Vinod

Undergraduate Academic Research Journal

T-junctions are one of the most difficult pipe fitting in terms of calculation of the head loss occurring through it. Various attempts have been made to derive the value of loss coefficients of the two branches of the tjunctions. Some formulas which involve area ratios and flow ratios are available. However, the use of these coefficients has to be further scrutinized. The erroneous effect of the use of constant loss co-efficients needed to understood and reviewed. This has been done, through the use of a standard network and the simplest network having one T-junction. Further efforts have been made to …

Master Plan Of Water Distribution System For Srinagar And Hanumanth Nagar Wards - Using Epanet, Sneha G, Nikhil B, K Galajalaxmi Prof., Syed Abdulla Furkhan, Narasimhamurthy H, Jagadish Babu Mr.

Undergraduate Academic Research Journal

Every metropolitan city requires a master plan which provides a conceptual layout to guide future growth and development of the city. One of the reasons for water crisis in developing countries is due to inefficient and wasteful water management systems. In this research paper EPANET is used to build the water network model, optimize it, compute head-loss, velocity of flow in each node and flow in each pipe in the water distribution. It can be used to consider and understand the growth of the demand of city with the design period of 30 years. The above knowledge is used to …

Simulating The Impact Of Urban Sprawl In Spatiotemporal Variation Of Air Pollution In Bangalore Region Using Ml And Gis., Gagan Vernekar, Dhanush B. Naidu, K Galajalaxmi Prof., Kiran K, Manjunatha Havinal

Undergraduate Academic Research Journal

The rapid expansion of urban areas due to rise in population and economic growth is increasing the additional demand on natural resources thereby causing land-use changes especially in megacities. Bengaluru, being a city of India’s high-tech industry has been facing deteriorating environmental conditions. This paper deals with studying the problems by designing the Machine Learning (ML) model which helps in detecting the Green Cover Change, Urban sprawl, Air Quality Parameters concentration in Bangalore region for the future and analyse them with Geographic Information System (GIS) data’s using Remote Sensing (RS) satellite images of various years of Bangalore city along with …

Time Motion Study On Soil Protection Works, Santosh Tekkannavar

Undergraduate Academic Research Journal

Soil protection works have become popular due to their immense contribution to protecting the building from land sliding. A building structure requires a stable foundation to ensure best construction and durability. There are various engineering techniques in soil protection works, this paper consists of the Soil nailing procedure adopted in the Northwest Commercial multi-use (NWCM) Project of Karle Infra Pvt. Ltd Company, currently executed by the vendor Geoengineering Pvt. Ltd. Soil nailing technique is used to stabilize the existing slope and construct retaining walls from top down. Steel nails are used as a reinforcement of soil which are drilled and …

Development Of Deep Shear Wave Velocity Profiles And An Approach To Generate Site Signature Consistent Pseudo Shear Wave Velocity Profiles In The Mississippi Embayment, Ashraf Kamal Himel

Graduate Theses and Dissertations

This dissertation details the development of a surface wave method (SWM) technique to generate deep shear wave velocity profiles (VS profiles), applying this technique at 24 sites across the Mississippi embayment and developing an approach to generate pseudo site signature consistent VS profiles from velocity functions and fundamental frequency. In the presented SWM technique, active and passive source surface wave measurements are inverted along with fundamental frequency to develop a site signature consistent VS profile. Multiple transformation methods, including MSPAC, HRFK and FK are used to resolve experimental dispersion data from surface wave measurements. SWM VS profile at the Central …

Compound Flooding In Convergent Estuaries: Insights From An Analytical Model, Ramin Familkhalili, Stefan Talke, David A. Jay

Civil & Environmental Engineering Faculty Publications

We investigate here the effects of geometric properties (channel depth and cross-sectional convergence length), storm surge characteristics, friction, and river flow on the spatial and temporal variability of compound flooding along an idealized, meso-tidal coastal-plain estuary. An analytical model is developed that includes exponentially convergent geometry, tidal forcing, constant river flow, and a representation of storm surge as a combination of two sinusoidal waves. Nonlinear bed friction is treated using Chebyshev polynomials and trigonometric functions, and a multi-segment approach is used to increase accuracy. Model results show that river discharge increases the damping of surge amplitudes in an estuary, while …

Temporal Lidar Scanning In Quantifying Cumulative Rockfall Volume And Hazard Assessment: A Case Study At Southwestern Saudi Arabia, Abdullah A. Alotaibi, Norbert H. Maerz, Kenneth J. Boyko, Ahmed M. Youssef, Biswajeet Pradhan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Rockfalls and unstable slopes pose a serious threat to people and property along roads/highways in the southwestern mountainous regions of Saudi Arabia. In this study, the application of terrestrial light detection and ranging (LiDAR) technology was applied aiming to propose a strategy to analyze and accurately depict the detection of rockfall changes, calculation of rockfall volume, and evaluate rockfall hazards along the Habs Road, Jazan Region, Saudi Arabia. A series of temporal LiDAR scans were acquired at three selected sites. Our results show that these three sites have different degrees of hazard due to their geological differences. The mean volume …

Permeability And Porosity Of Loose Granular Salt, Evan J. Babcock

Civil Engineering ETDs

In this study, permeability and porosity measurements are made and reported for loose granular salt from the Waste Isolation Pilot Plant (WIPP). Measurements are made on a particularly wide range of particle sizes of this salt in a permeameter constructed large enough to fit and represent mixtures containing salt particles up to 25.4 cm in size. Salt samples with different particle size distributions are constructed and tested at varying levels of consolidation due to induced vibrations. Permeability measurements are made at a varying range of porosities for a given sample. Measurements are also compared with a predictive model for permeability …

Assessment Of Geo-Mechanical Properties Of Lunar Simulants, Devansh Joshi

Electronic Thesis and Dissertation Repository

Abstract

Sophisticated manned and unmanned lunar missions are being developed by international collaborations of the USA, Canada, EU, India, China, Japan etc. for a long-term human presence on the moon. These lunar missions require prototype testing of rovers and other hardware on the earth to successfully interact with the lunar surface. This laboratory testing requires various simulant (terrestrial soil mimicking one or more lunar regolith characteristics) testbeds. Actual lunar soil is too pristine and scarce to be used for destructive testing. Hence, simulants have been developed by research institutions, space research organizations, or commercial manufacturers to cater to a wide …