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2002

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Articles 1531 - 1560 of 1792

Full-Text Articles in Engineering

Development Of A Micro Power Relay With Static Electrical Actuator, Ren Yang Jan 2002

Development Of A Micro Power Relay With Static Electrical Actuator, Ren Yang

LSU Master's Theses

In this thesis, a research about design and fabrication of a micro power relay is presented. Compared with the traditional electromagnetic relay and solid-state relay, MEMS micro power relay is introduced. After introducing the advantage and other people's research about the MEMS relay, some design and simulation about a new prototype micro power relay are done. Based on the design, UV-LIGA is used as the fabrication method. The bottom part and top part of the micro power relay are fabricated separately. After assembly the top part on the bottom part, some simple tests about the micro power relay are done. …

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The Effects Of Rock And Fluids Characteristics On Reservoir Wettability, Chandra S. Vijapurapu Jan 2002

The Effects Of Rock And Fluids Characteristics On Reservoir Wettability, Chandra S. Vijapurapu

LSU Master's Theses

Wettability is the ability of a fluid to spread or adhere on a rock surface in the presence of other immiscible fluids. Knowledge of wettability is important to decide what production strategy needs to be employed for optimum oil recovery. Wettability is affected by rock mineralogy, rock surface roughness, and brine compositions. Previous studies have dealt with solid-liquid-vapor systems and those involving wettability characterization in solid-liquid-liquid systems have used contact angle techniques known to have reproducibility problems. In this study, a new technique called the Dual-Drop-Dual-Crystal (DDDC) Technique has been used to characterize wettability in terms of dynamic contact angles. …

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Information Domain Modeling Of Emergent Phenomena, Ron Fulbright Jan 2002

Information Domain Modeling Of Emergent Phenomena, Ron Fulbright

Theses and Dissertations

Study in fields such as distributed artificial intelligence (DAI), decentralized artificial intelligence (DzAI), parallel artificial intelligence (PAl), multiagent systems (MAS), computer supported cooperative work (CSCW), artificial life (AL), and complex adaptive systems (CAS) is concerned with the cooperation, coordination, communication, and coherence of multiple agents working together to achieve a common goal. The notion that the ability of a collective can exceed the sum of the individuals is a fundamental concept and a generally accepted truth. However, no general theoretical explanation exists as to why this could or should be the case. This dissertation explores such an explanation by considering …

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Whispering-Gallery Modes In Shielded Hemispherical Dielectric Resonators, Sergey Kharkovsky, Z. E. Eremenko, V. V. Kutuzov, A. E. Kogut, Yuri F. Filipov Jan 2002

Whispering-Gallery Modes In Shielded Hemispherical Dielectric Resonators, Sergey Kharkovsky, Z. E. Eremenko, V. V. Kutuzov, A. E. Kogut, Yuri F. Filipov

Electrical and Computer Engineering Faculty Research & Creative Works

The results of the numerical and experimental investigations of whispering-gallery (WG) modes in shielded hemispherical dielectric resonators are presented in this paper. It is shown that the Q factor of WG modes in the shielded resonator can be ten times much higher than the Q factor of the similar open hemispherical dielectric-resonator modes. Shielding the resonator can decrease the dimensions of both the dielectric hemisphere and resonator as a whole, saving the high-Q factor of WG modes. The usage of a cylindrical shield and local flat reflectors in the experiment provides the investigation of the high-Q factor of WG modes …

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Full Binary Combination Schema For Floating Voltage Source Multilevel Inverters, Xiaomin Kou, Keith Corzine, Yakov L. Familiant Jan 2002

Full Binary Combination Schema For Floating Voltage Source Multilevel Inverters, Xiaomin Kou, Keith Corzine, Yakov L. Familiant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents schema of operation for floating voltage source multilevel inverters. The primary advantage of the proposed schema is that the number of voltage levels (and thus power quality) can be increased for a given number of semiconductor devices when compared to the conventional "flying capacitor" topology. However, the new schema requires fixed floating sources instead of capacitors and therefore is more suitable for battery power applications such as electric vehicles, flexible AC transmission systems and submarine propulsion. Alternatively transformer/rectifier circuits may be used to supply the floating sources in a similar way to cascaded H-bridge inverters. Computer simulation …

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Forensic Investigation Of Failed Mast Arms Of Traffic Signal Supported Structures, Genda Chen, Michael G. Barker, D. Scott Mackenzie, Christopher W. Ramsay, Joe Alderson, Lokeswarappa R. Dharani, Jiaqing Yu Jan 2002

Forensic Investigation Of Failed Mast Arms Of Traffic Signal Supported Structures, Genda Chen, Michael G. Barker, D. Scott Mackenzie, Christopher W. Ramsay, Joe Alderson, Lokeswarappa R. Dharani, Jiaqing Yu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Missouri, 11 traffic signal mast arms fractured at the arm-post weld connection in 7 years. To reduce this fatigue failure, the Missouri Department of Transportation developed a fatigue-resistant weld profile that increases the weld leg and reduces the slope of the weld at the toe. This study investigated causes of the failed arms, compared performance of new and old weld profiles, and suggested retrofitting measures for further investigation. The scope included a metallurgical investigation of one failed field mast arm, laboratory fatigue testing of five prototype mast arms (two new and three old profiles), and laboratory failure analysis of …

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Mobile Home Security With Gprs, Duy Nguyen Jan 2002

Mobile Home Security With Gprs, Duy Nguyen

Theses : Honours

This thesis presents the results of an honours project on the development of a security system for use on mobile devices. Mobile Home Security (MHS) is a prototype system that aimed to fully investigate a potential use of the wireless high-speed technology General Packet Radio Service (GPRS) in transmitting video from a static location. This thesis Mobile Home Security with GPRS describes in detail the design and developmental stages for the system. The research focused on the sending of video from a security capture device over a high speed radio network. The first stage of the research involved the design …

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Trusted Autonomy, Michael N. Huhns, Duncan A. Buell Jan 2002

Trusted Autonomy, Michael N. Huhns, Duncan A. Buell

Faculty Publications

We describe how agents are the right building blocks for constructing trustworthy systems. Robust software and trusted autonomy represent the future for agent technology and software engineering.

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Weaving A Computing Fabric, Michael N. Huhns, Larry M. Stevens, John W. Keele, Jim E. Wray, Warren M. Snelling, Greg P. Harhay, Randy R. Bradley Jan 2002

Weaving A Computing Fabric, Michael N. Huhns, Larry M. Stevens, John W. Keele, Jim E. Wray, Warren M. Snelling, Greg P. Harhay, Randy R. Bradley

Faculty Publications

As sources of information relevant to a particular domain proliferate, we need a methodology for locating, aggregating, relating, fusing, reconciling, and presenting information to users. Interoperability thus must occur not only among the information, but also among the different software applications that process it. Given the large number of potential sources and applications, interoperability becomes an extremely large problem for which manual solutions are impractical. A combination of software agents and ontologies can supply the necessary methodology for interoperability.

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Agents As Web Services, Michael N. Huhns Jan 2002

Agents As Web Services, Michael N. Huhns

Faculty Publications

Web services are extremely flexible. Most advantageously, a developer of Web services need not know who or what will use the services being provided. The paper discusses current standards for Web services, directory services and the Semantic Web. It considers how agents extend Web services in several important ways.

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Robust Software, Michael N. Huhns, Vance T. Holderfield Jan 2002

Robust Software, Michael N. Huhns, Vance T. Holderfield

Faculty Publications

Agents offer a convenient level of granularity at which to add redundancy a key factor in developing robust software. Blindly adding code introduces more errors, makes the system more complex, and renders it harder to understand. However, adding more code can make software better, if it is added in the right way. As this article describes, the key concepts appear to be redundancy and the appropriate granularity.

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Agent Societies: Magnitude And Duration, Michael N. Huhns Jan 2002

Agent Societies: Magnitude And Duration, Michael N. Huhns

Faculty Publications

If you only need agents to search the Web for cheap CDs, scalability is not an issue. The Web can support numerous agents if each acts independently. In short order, however, billions of embedded agents that sense their environment and interact with us and other agents will fill our world, making the human environment friendlier and more efficient. These agents will need not only scalable infrastructures and communication services, but also scalable social services encompassing ethics and laws. Research projects are under way around the world to develop and deploy such services. The author takes a look at the critical …

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High Definition Manufacturing Cell Model, Wayne Wakeland, Leupold & Stevens, Inc. Jan 2002

High Definition Manufacturing Cell Model, Wayne Wakeland, Leupold & Stevens, Inc.

Complex Systems Faculty Publications and Presentations

The purpose was to study the capacity, staffing requirements and alternative equipment configurations. This presentation provides a preview of the results.

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Modeling Of Electrofusion Coils For Performance Optimization, Steve Farmer, Robert A. Sims Jan 2002

Modeling Of Electrofusion Coils For Performance Optimization, Steve Farmer, Robert A. Sims

Journal of the Arkansas Academy of Science

Modeling physical parameters provides a virtual design environment allowing the confirmation and optimization of electrofusion characteristics. Finite element incorporate physical parameters and their interactions along common boundaries defined within a model geometry. The electrofusion of polymeric piping is a widely accepted means of assembling piping systems with zero-leakage integrity. The key parameters in the fusion process are the coil resistance, the current passing through the coil and the time the current is applied. Modeling the coil and applying current to the model is accomplished using the MATLABpartial differential equations (PDE) toolbox. This paper presents the method of modeling and the …

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Co-Polymers Of Furan With Pyrrole Or Thiophene: A Synthetic Study, Rose M. Mcconnell, Walter E. Godwin, Susan E. Baker, Kenya Powell, Martha Baskett, Amy Morara, Xiadong Ma Jan 2002

Co-Polymers Of Furan With Pyrrole Or Thiophene: A Synthetic Study, Rose M. Mcconnell, Walter E. Godwin, Susan E. Baker, Kenya Powell, Martha Baskett, Amy Morara, Xiadong Ma

Journal of the Arkansas Academy of Science

The use of conductive polymers as a substitute for metallic conductors and semiconductors has attracted much attention in the literature. In particular, aromatic heterocyclic polymers constitute an important class since they possess chemical and electrical stability in both the oxidized (doped) and neutral (undoped) state. Doping a polymer allows one to vary its electrical, mechanical, optical, and thermal properties. The properties of these polymers are promising for their many technological uses such as antistatic coatings, solar cells, and electronic devises. Polyfuran is among the least common heterocyclic polymers. Polyfuran has been reported to be much less stable that either polypyrrole …

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Pressure And Flow Validation Of A Second Generation Gas Extraction Probe For A Hybrid Rocket Gas Extraction System, Constance Meadors, Andrew B. Wright Jan 2002

Pressure And Flow Validation Of A Second Generation Gas Extraction Probe For A Hybrid Rocket Gas Extraction System, Constance Meadors, Andrew B. Wright

Journal of the Arkansas Academy of Science

A gas extraction system (GES) has been designed for use with the hybrid rocket facility at the University of Arkansas at Little Rock (UALR) for spectroscopic analysis of rocket plumes. While monitoring gas flow-rate and pressure, the GES extracts gases from the hybrid rocket plume and transports them to a mass spectrometer. This paper describes design and construction of a gas extraction probe (GEP) prototype capable of extracting gases directly from the plume. Gas dynamics equations were used to design two venturi-type GEP, converging and converging-diverging. The probe was tested with air to verify design assumptions. Flow rate through the …

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Mechanism For Membrane Electroporation Irreversibility Under High-Intensity, Ultrashort Electrical Pulse Conditions, R. P. Joshi, K. H. Schoenbach Jan 2002

Mechanism For Membrane Electroporation Irreversibility Under High-Intensity, Ultrashort Electrical Pulse Conditions, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

An improved electroporation model is used to address membrane irreversibility under ultrashort electric pulse conditions. It is shown that membranes can survive a strong electric pulse and recover provided the pore distribution has a relatively large spread. If, however, the population consists predominantly of larger radii pores, then irreversibility can result. Physically, such a distribution could arise if pores at adjacent sites coalesce. The requirement of close proximity among the pore sites is more easily satisfied in smaller organelles than in outer cell membranes. Model predictions are in keeping with recent observations of cell damage to intracellular organelles (e.g., mitochondria), …

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Self-Assembly Of Spatially Separated Silicon Structures By Si Heteroepitaxy On Ni Disilicide, Elena A. Guliants, Chunhai Ji, Wayne A. Anderson Jan 2002

Self-Assembly Of Spatially Separated Silicon Structures By Si Heteroepitaxy On Ni Disilicide, Elena A. Guliants, Chunhai Ji, Wayne A. Anderson

Electrical and Computer Engineering Faculty Publications

A nonlithographic approach to produce self-assembled spatially separated Si structures for nanoelectronic applications was developed, employing the metal-induced silicon growth. Densely packed Si whiskers, 500–800 nm thick and up to 2500 nm long, were obtained by magnetron sputtering of Si on a 25 nm thick Ni prelayer at 575 °C. The nucleation of the NiSi2 compound at the Ni–Si interface followed by the Si heteroepitaxy on the lattice-matched NiSi2 is suggested to be the driving force for the whisker formation.

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Iron Phosphate Glass For The Vitrification Of Ineel Sodium Bearing Waste And Hanford Low Activity Waste, Robert Douglas Leerssen Jan 2002

Iron Phosphate Glass For The Vitrification Of Ineel Sodium Bearing Waste And Hanford Low Activity Waste, Robert Douglas Leerssen

Masters Theses

"The current study investigates the feasibility of using iron phosphate glass for the immobilization of nuclear wastes that have limited solubility in the current borosilicate glass used for vitrification. These wastes contain elements such as sulfur and phosphorus, which have proven problematic (causing phase separation at >1 wt%) for vitrification in borosilicate glasses, as well as having a high soda content (50-75 wt%) which also limits wasteloading"--Abstract, page iv.

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An Evaluation Of Innovative Transportation Financing Techniques For Indiana, Kristine Drike, A. Vincent Genetti, Kumares C. Sinha Jan 2002

An Evaluation Of Innovative Transportation Financing Techniques For Indiana, Kristine Drike, A. Vincent Genetti, Kumares C. Sinha

JTRP Technical Reports

Innovative financing techniques can complement current methods of financing highway projects in Indiana. Annual federal apportionments and Indiana state revenues are not sufficient to maintain and improve state highways, so innovative approaches in transportation project financing should be sought. There are several available innovative financing techniques associated with the use of federal funds. Although, they do not provide new sources of revenue and cannot create enough funds for all identified projects, they provide flexibility in the use of available funds that can expedite the implementation of individual projects. The main objective of this study was to evaluate the major innovative …

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Design Of Durable Concrete Railroad Crossings, Anthony J. Lamanna, Charles F. Scholer Jan 2002

Design Of Durable Concrete Railroad Crossings, Anthony J. Lamanna, Charles F. Scholer

JTRP Technical Reports

Existing precast concrete railroad crossings in the state of Indiana are experiencing too short a life expectancy. This study proposes methods that can be used to produce durable concrete railroad crossings with satisfactory rideability, durability, and longevity. Thirty-two precast concrete railroad crossings were visited in central and northern Indiana. Failures were determined to belong to three major categories: structural capacity causes, environmental causes, and material property causes. A concrete mix was evaluated at three different polyolefin fiber contents and without fibers. Beams were tested in flexure, and modulus of rupture and first crack deflection were recorded for each beam. Cylinders …

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Design Of Mse Walls For Fully Saturated Conditions, Antonio Bobet Jan 2002

Design Of Mse Walls For Fully Saturated Conditions, Antonio Bobet

JTRP Technical Reports

The current design of MSE walls, which is based on limit state analysis, does not apply to undrained conditions. Laboratory and numerical pullout tests are performed to determine the relation between drained and undrained pullout capacities for different soil types (clean sand, 5, 10, 15 and 35 % silty sand), overburden pressures (30, 100 and 200 kPa), and scale and permeability effects in the dissipation of excess pore pressures. The results of the pullout tests show that both drained and undrained pullout capacities change as silt content changes since the pullout capacity increases as the internal friction angle of the …

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Effectiveness Of The Borman Expressway Its Program On Local Air Quality, Timothy M. Labreche, Robert Bertram Jacko, Barry K. Partridge, William H. Schneider, Ahmed S. Soliman Jan 2002

Effectiveness Of The Borman Expressway Its Program On Local Air Quality, Timothy M. Labreche, Robert Bertram Jacko, Barry K. Partridge, William H. Schneider, Ahmed S. Soliman

JTRP Technical Reports

Particulate Matter less than 2.5 μm in diameter (PM2.5), carbon monoxide (CO), and meteorological parameters were monitored at 10 second averaging intervals adjacent the Borman Expressway in Northwestern Indiana before and during the implementation of an Intelligent Transportation System. Traffic data was collected from sensors on the expressway. The high-resolution data permitted the expressway contribution to local air quality to be separated from background components of local air quality and significant correlations were made between pollutant flux and traffic flow and pollutant flux and highway occupancy. Traffic incidents (accidents / congestion) were shown to have a rapid impact on local …

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Effects Of Heavier Truck Loadings And Super-Single Tires On Subgrades, Rodrigo Salgado, Daehyeon Kim Jan 2002

Effects Of Heavier Truck Loadings And Super-Single Tires On Subgrades, Rodrigo Salgado, Daehyeon Kim

JTRP Technical Reports

Due to their efficiency and economy, super-single tires have gradually been replacing conventional dual tires in the trucking industry. According to recent studies, super-single tires generate much higher vertical contact stresses than do conventional dual tires, resulting in larger deformations and more severe damage to the subgrade. In order to better assess the higher stresses generated by super-single tires and their effect on the subgrade, analyses are done taking into account soil plasticity rather than simple elastic analysis. In this study, the effects of super-single tires on subgrades for typical road cross-sections are investigated using plane-strain (2D) and 3D static …

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Fatigue Behavior Of Beam Diaphragm Connections With Intermittent Fillet Welds, Part I, Volume 1, Field Evaluation, Tammy L. Canna, Mark D. Bowman Jan 2002

Fatigue Behavior Of Beam Diaphragm Connections With Intermittent Fillet Welds, Part I, Volume 1, Field Evaluation, Tammy L. Canna, Mark D. Bowman

JTRP Technical Reports

This report is the first of a two-part, three volume final report presenting the findings of the research work that was undertaken to evaluate the behavior of Indiana highway bridges with diaphragm members welded directly to the web of the primary beams and girders. Fatigue cracks have been observed at several bridges that utilize the welded diaphragm connection. The seriousness of the cracking and the corresponding potential risk on the integrity of the bridge superstructure were assessed. Inspection and repair guidelines for bridges with the welded diaphragm connections were also developed as part of the research effort. This volume presents …

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Guidelines For Use And Types Of Retaining Devices, Antonio Bobet Jan 2002

Guidelines For Use And Types Of Retaining Devices, Antonio Bobet

JTRP Technical Reports

A large number of types of retaining devices are currently available but their limitations, recommendations and guidelines are scattered in the technical literature. A synthesis study has been made in which different technologies have been investigated to develop guidelines for the use of the different types of retaining devices. For this purpose, an extensive literature review has been performed and a new classification has been proposed. An electronic database with 207 selected cases from the technical literature and INDOT archives has been created. The database stores the following information: (1) Type of Retaining Device; (2) Geometry (3) Soil conditions; (4) …

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Improving Efficiency Of Indot Traffic Data Collection Using Gps Devices, Shuo Li, Karen Zhu, Boudewijn H. W. Van Gelder, John Nagle, Carl Tuttle Jan 2002

Improving Efficiency Of Indot Traffic Data Collection Using Gps Devices, Shuo Li, Karen Zhu, Boudewijn H. W. Van Gelder, John Nagle, Carl Tuttle

JTRP Technical Reports

INDOT has utilized many new technologies to reduce travel delay, mitigate traffic congestion, and enhance public and employees’ safety. Many projects are underway, including re-timing of most existing traffic signals and pavement maintenance and rehabilitation. To evaluate signal system performance, prioritize alternatives of improvement, conduct before and after studies and investigate work zone safety, it requires a large amount of traffic data such as travel time, speed and delay. Issues, such as safety, efficiency and cost, may arise associated with the current methods. For the current manual or automatic data collection, it usually requires two operators, a driver and a …

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Internet-Supported Evaluation Of Highway Safety, Andrzej P. Tarko, Brian Desalle Jan 2002

Internet-Supported Evaluation Of Highway Safety, Andrzej P. Tarko, Brian Desalle

JTRP Technical Reports

Few current methods of identifying hazardous locations take into account the perspective of highway users. It is generally accepted by human factor experts that user feedback can provide valuable insight into safety at highway locations that is not obtainable through the use of crash data. However, little research has been conducted in the highway transportation area, and the relationship between user perception and actual safety at a location is not well known. Currently, motorist feedback in Indiana is gathered by individual highway agencies through the use of a phone and mail collection process. A centralized feedback collection would not only …

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Mid-Panel Cracking Of Portland Cement Concrete Pavements In Indiana, Hung-Ming Chen, Yunus Dere, Elisa D. Sotelino, Graham C. Archer Jan 2002

Mid-Panel Cracking Of Portland Cement Concrete Pavements In Indiana, Hung-Ming Chen, Yunus Dere, Elisa D. Sotelino, Graham C. Archer

JTRP Technical Reports

Portland cement concrete slabs are a common form of highway pavements in Indiana. As a result of their widespread use, the economic impact of their maintenance and life span is therefore tremendous. In Indiana, these types of pavements have been experiencing premature random transverse mid-panel cracking. This phenomenon has been observed under a variety of environmental and traffic conditions. Also, it has been found that the cracking occurs in conjunction with the opening of the lanes to traffic, within months of construction. In this project, a research synthesis was carried out to determine exactly what the current state of knowledge …

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Load Tests On Pipe Piles For Development Of Cpt-Based Design Method, Kwangkyum Kim, Rodrigo Salgado, Junhwan Lee, Kyuho Paik Jan 2002

Load Tests On Pipe Piles For Development Of Cpt-Based Design Method, Kwangkyum Kim, Rodrigo Salgado, Junhwan Lee, Kyuho Paik

JTRP Technical Reports

This research focused on the drivability and load-carrying capacity of both open and closed-ended steel pipe piles. Two pipe piles (one open-ended, the other closed-ended) were installed in a sandy soil to the same depth. The site was extensively characterized. SPT and CPT tests were performed both before and after pile installation. A variety of soil indices and shear strength parameters (such as the constant-volume friction angle) were measured in the laboratory. The piles were fully instrumented, permitting separate measurement of shaft and base capacity for the closed-ended pile and shaft, annulus and soil plug capacities for the open-ended pile. …

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