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Full-Text Articles in Engineering
Long-Term Trends From Ecosystem Research At The Hubbard Brook Experimental Forest, John L. Campbell, Charles T. Driscoll, Christopher Eagar, Gene E. Likens, Thomas G. Siccama, Chris E. Johnson, Timothy J. Fahey, Steven P. Hamburg, Richard T. Holmes, Amey S. Bailey, Donald C. Buso
Long-Term Trends From Ecosystem Research At The Hubbard Brook Experimental Forest, John L. Campbell, Charles T. Driscoll, Christopher Eagar, Gene E. Likens, Thomas G. Siccama, Chris E. Johnson, Timothy J. Fahey, Steven P. Hamburg, Richard T. Holmes, Amey S. Bailey, Donald C. Buso
Civil and Environmental Engineering
The Hubbard Brook Experimental Forest was established by the U.S. Forest Service in 1955 as a major center for hydrologic research in the Northeast. The Hubbard Brook Ecosystem Study originated 8 years later with the idea of using the small watershed approach to study element flux and cycling and the response of forest ecosystems to disturbance. Since that time, the research program at Hubbard Brook has expanded to include various physical, chemical and biological measurements collected by researchers from a number of cooperating institutions. Collaborative, long-term data are the keystone of the Hubbard Brook Ecosystem Study and have provided invaluable …
Effects Of Vertical Heterogeneity Of Soil Sediments On Seismic Soil Response, Srikanth Venkatesan, M Neaz Sheikh, Hing Ho Tsang, Nelson Lam
Effects Of Vertical Heterogeneity Of Soil Sediments On Seismic Soil Response, Srikanth Venkatesan, M Neaz Sheikh, Hing Ho Tsang, Nelson Lam
Faculty of Engineering - Papers (Archive)
Site effects are resulted from the non-linear filtering mechanisms within the soil sedimentary layers overlying bedrock. In contemporary design codes, site effects are taken into account by introducing different site factors for different site classes. The prescribed site classification systems are based on averaging shear wave velocity in the soil sediments. However, significant amplification of the seismic displacement demand may be developed from mechanisms which can result in resonance behaviour. In such situations, soil amplification cannot be determined accurately by considering the average shear wave velocity of the sediments alone. The effects of vertical heterogeneity in the soil sediments have …
Rubber-Soil Cushion For Earthquake Protection, Hing Ho Tsang, M Neaz Sheikh, Nelson Lam
Rubber-Soil Cushion For Earthquake Protection, Hing Ho Tsang, M Neaz Sheikh, Nelson Lam
Faculty of Engineering - Papers (Archive)
This paper proposes a promising seismic isolation method particularly suitable for developing countries using rubber-soil mixtures the CUSHION. Apart from reducing the level of shaking in the horizontal direction, the distinctive advantage of the proposed method is that it also significantly reduces the shaking level in the vertical direction, to which increasing attention has been paid by the earthquake engineering community. The use of scrap tyres as the rubber material can provide an alternative way to consume the huge stockpile of scrap tyres from all over the world. Moreover, the low-cost of this proposed seismic protection scheme can greatly benefit …
Numerical Modelling Of Dynamic Soil Liquefaction In Sloping Ground, Deepa S. Liyanapathirana
Numerical Modelling Of Dynamic Soil Liquefaction In Sloping Ground, Deepa S. Liyanapathirana
Faculty of Engineering - Papers (Archive)
In sloping ground, before application of dynamic loading, the ground is subjected to a static shear stress due to the weight of the soil and the slope of the ground. Static shear stresses will act as driving forces and cause very large ground deformations even before the onset of soil liquefaction. Therefore reliable prediction of soil response is essential in the assessment of remediation methods to reduce liquefaction induced soil deformation. This paper investigates the application of a stress path model to simulate the soil liquefaction in sloping ground. Pore pressure generation and liquefaction strength of the soil predicted by …
In Situ Enhanced Soil Mixing, Purdue Ect Team
In Situ Enhanced Soil Mixing, Purdue Ect Team
ECT Fact Sheets
In Situ Enhanced Soil Mixing (ISESM) is a remediation technology that has been used to remediate soils contaminated with volatile organic compounds (VOCs). The technology was developed by industry with the assistance of the U.S. Department of Energy’s Office of Science and Technology and the Office of Environmental Restoration.
Funnel & Gate System, Purdue Ect Team
Funnel & Gate System, Purdue Ect Team
ECT Fact Sheets
The limited success and high cost of traditional 'active' ground-water-contaminant plume management efforts (i.e., pump-and-treat systems) has stimulated a search for less expensive 'passive' plume interception and in-situ treatment technologies. The 'funnel and gate system,' which uses heterogeneous (surface-mediated) reactions on porous media to degrade dissolved contaminants, is one passive technology under consideration.
In Situ Remediation Using Horizontal Wells, Purdue Ect Team
In Situ Remediation Using Horizontal Wells, Purdue Ect Team
ECT Fact Sheets
Horizontal well technology has been widely used in petroleum and underground utility installation. Since late 1980's, the technology has been adapted for environmental remediation applications. Two general methods in drilling horizontal wells have been used in remediation, trenched and directionally-drilled. The first method involves the excavation of a relatively large diameter borehole, with simultaneous installation of well materials and backfill. The second method, directional drilling, produces a smaller diameter borehole and well materials are installed following the completion of drilling activities.
Jet-Grouting Constructed Laminar Diaphragms, Purdue Ect Team
Jet-Grouting Constructed Laminar Diaphragms, Purdue Ect Team
ECT Fact Sheets
The high cost of digging and hauling contaminated soil has made enclosure of the contaminated soil an alternative to prevent contamination of ground water and adjacent sites. The jet-grouting method uses special grout nozzles to create a grout sheet of controlled width and thickness from each drilled grout hole. This sheet is commonly 100 mm. to 150 mm. in thickness, 2 to 3 meters in width, and of any desired length. The width of the sheet in one pass can go up to 6 meters. Actual lateral soil penetration of the grout jets is a function of the nature of …
Extraction Of Contaminated Soil Using High Pressure Jet Grouting, Purdue Ect Team
Extraction Of Contaminated Soil Using High Pressure Jet Grouting, Purdue Ect Team
ECT Fact Sheets
Removal of contaminated soil underneath existing structures causes settlement. There is a need for a remediation technology that eliminates this problem. The jet grouting by the triple rod system can be combined with an on site remediation technology (e.g., soil washing). Jet grouting was developed primarily for underpinning and/or excavation support. The benefits of this technology lie in the future reduction of structural settlement, and site access flexibility.
Glass Diaphragm Walls, Purdue Ect Team
Glass Diaphragm Walls, Purdue Ect Team
ECT Fact Sheets
The materials currently applied to confine contaminated soils are not the best solution (ex. slurry walls). A new contaminant confining material is presented where the costs of digging and hauling the contaminated soil are eliminated. For contaminant enclosure, the new technology incorporates a diaphragm wall system consisting of special glass panels with a sealing made out of glass.
In-Situ Vitrification, Purdue Ect Team
In-Situ Vitrification, Purdue Ect Team
ECT Fact Sheets
While landfills are the predominant form of solid-waste disposal for municipalities in the U.S., people are objecting to the establishment of new landfills in their communities. Decreasing availability of land, worries about potential health problems and a growing concern for the environment have made the disposal of solid waste a challenge. This technology represents a safety improvement. There is no need for contaminated soil transportation and handling. The need for disposal landfills disappears. Any type of radioactively contaminated buried waste unit, which because of its high activity represents significant risk for exhumation and re-disposal, would be a potential application for …
Ehydraulic Pneumatic Fracturing, Purdue Ect Team
Ehydraulic Pneumatic Fracturing, Purdue Ect Team
ECT Fact Sheets
The technology is an enhancement process designed for integration with primary in-situ treatment technologies such as vapor extraction, bioremediation, thermal treatment, and 'pump and treat'. Fractures in dense soils are created, using hydraulic or pneumatic methods, making existing fractures larger to get at contaminants and allowing a more effective distribution of the extractive air throughout the soil. Pneumatic Fracturing was jointly developed by Accutech Remedial Systems Inc. and the New Jersey Institute of Technology. It involves the injection of air (or another gas) into a contaminated geologic formation at sufficient pressure and flow rate to create artificial fractures or to …
Undrained Shear Strength Of A Residual Soil Measured By Triaxial And Direct Simple Shear Tests, G H. Meng, J Chu, C Klotz
Undrained Shear Strength Of A Residual Soil Measured By Triaxial And Direct Simple Shear Tests, G H. Meng, J Chu, C Klotz
Faculty of Engineering - Papers (Archive)
The undrained shear strength of soil is one of the most important parameters required for geotechnical design. Depending on the design situations, the undrained shear strength of soil may have to be determined by different tests. In this paper, some testing data on the determination of the undrained shear strength of a residual soil in Singapore are presented. A series of tests including Ko consolidated undrained triaxial compression and extension tests, and Ko consolidated undrained direct simple shear tests have been conducted on large block undisturbed soil samples taken from the construction site ofT-06 (Queensway Tunnel) of the Deep Tunnel …
Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke
Improved Parameterization To Invert Rayleigh-Wave Data For Shallow Profiles Containing Stiff Inclusions, Carlos Calderon-Macias, Barbara Luke
Civil and Environmental Engineering and Construction Faculty Research
Inversion of shear-wave velocity profiles from phase-velocity measurements of Rayleigh-wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model. Incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution. Resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer, uncemented media is an application for which locating shallow stiff inclusions has important implications. Identification of the stiff layers is critical for foundation design and cost estimating of excavations. A parameterization that seems adequate for this …
Plasma Arc Torch Technology Stabilization And Ground Improvement, Purdue Ect Team
Plasma Arc Torch Technology Stabilization And Ground Improvement, Purdue Ect Team
ECT Fact Sheets
This technology represents an additional alternative for stabilizing weak foundation soils upon which buildings, bridges, roads or other structures are to be constructed. A plasma is a gas that has been ionized by the electric arc of a plasma torch and can therefore respond to electrical and magnetic fields. Plasma arc technology can create plasma using almost any type of gas (oxygen, nitrogen, carbon monoxide, air, etc.) and in a wide range of pressures (vacuum to 20 atmospheres).