Geotechnical/Geoenvironmental Engineering

Research Project Abstracts: 2006 - 2007

Development of Permeable Reactive Barriers (PRBs) using Edible Oils
R.C. Borden
Department of Defense, SERDP
01/01 to 01/07
The overall objective of this proposal is to develop the information needed to reliably design, construct, and evaluate edible oil barriers, including (1) identify factors controlling the loss of permeability during oil injection; (2) identify factors controlling oil biodegradation rate in aquifer sediments; (3) use these results to develop improved procedures for distributing and immobilizing oils that (a) do not cause an excessive decline in permeability, and (b) result in a slow, steady rate of in situ oil decay; and (4) use emulsion transport model to identify alternative barrier configurations and injection procedures to improve barrier performance and reduce costs.

Anaerobic Biotreatment of Acid Mine Drainage at Ore Knob Mine
R.C. Borden
NC Department of Environment and Natural Resources
08/05 to 07/08
Ore Knob Branch and Peak Creek are impaired due to discharge of acid mine drainage (AMD) from an abandoned copper/zinc mine. AMD production from the large tailings impoundment will be controlled by injecting emulsified soybean oil into the sediments to stimulate growth of naturally occurring bacteria. These bacteria will then use the soybean oil as a food source, consuming any dissolved oxygen and stopping further AMD production. Once oxygen is depleted, the sulfate reducing bacteria will reduce sulfuric acid to sulfide and precipitating heavy metals.

Development of a Design Tool for Planning Aqueous Amendment Injection Systems
R.C. Borden (NCSU), G. Mahinthakumar (NCSU) T. J. Simpkin (CH2M HILL) and C. Zawtocki (Solutions-IES)
DOE, Environmental Security Technology Certification Program
03/06 to 12/08
The overall objective of this project is to develop a set of tools to assist design engineers in developing effective, reasonably efficient systems for distributing aqueous amendments for in situ treatment of groundwater contaminants. At this time, the primary applications for the tools will be for design of in situ chemical oxidation systems using permanganate and in situ anaerobic bioremediation systems using soluble substrates and emulsified oil. However, as technology evolves, this general approach should be applicable to distribution of other aqueous amendments.

Treatment of Acid Mine Drainage Using Emulsified Soybean Oil
R.C. Borden
United Soybean Board (through Smith, Bucklin & Associates, LLC)
08/05 to 07/07
The United Soybean Board will provide matching support for a NC Department of Environment and Natural Resources (NC DENR) project to evaluate the use of emulsified soybean oil for treatment of acid mine drainage at the Ore Knob Mine in Ashe County, NC.

Impacts of Sampling and Handling Procedures on DNA- and RNA-based Microbial Characterization and Quantification of Groundwater and Saturated Soil
F. L. de los Reyes III and R. C. Borden
Strategic Environmental Research and Development Program
03/07 to 06/09
The overall objective of this project is to determine the relationships of sample processing procedures to the effectiveness and efficiency of three molecular techniques used in qualitative and quantitative analysis of microbial populations in groundwater and associated saturated soil samples.

Numerical Study of Loading Conditions with Applications Using a Particulate Approach
T.M. Evans
Unsponsored (new faculty start-up funds)
01/06 to present
Axisymmetric laboratory tests are typically used for the characterization of the mechanical response of granular soils when determining design parameters. However, many of the structures of interest to geotechnical engineers result in plane strain loading conditions in the field (e.g., retaining walls, highway embankments). It is well understood that laboratory tests having plane strain boundary conditions will produce different results than those performed under axisymmetric boundary conditions. However, what is not understood is how these differences manifest themselves in soil microstructure and in field performance. The current study seeks to provide insight into these topics.

Geosynthetics Workplan
M.A. Gabr
FHWA
09/05 to 08/06
No definitive guidance on the value of systematically including geosynthetics in highway construction projects is currently available for the Federal Land Program of FHWA. It has been identified by engineers that geosynthetics are "under-used in Federal Lands Highway practice." Accordingly, this study aims at developing a geosynthetics work plan to identify, promote, and advance the use of geosynthetics materials across FLH Divisions in the Pavement and Geotechnical areas. The target areas include pavement and geotechnical applications. Geotechnical applications will be focused on slopes, walls, base reinforcement, column supported embankments, capillary barriers to mitigate frost heaving, deep patches for soft shoulders, and geocomposite clay liners to control seepage from ditches.

Geologic and Environmental Modeling for Implementation of WIDE at Former Lockbourne Air Force Base
M.A. Gabr
Department of Defense, through W. Virginia University Water Resources Institute
07/05 to 06/07
This project implements Well Injection Depth Extraction (WIDE) technology for removal of JP-4 aviation fuel from the subsurface. Performance evaluation for deployment of WIDE will be performed with continuous monitoring for optimization of contaminant extraction. Baseline comparison of expanded deployment pads to existing field installation will be conducted and results compiled to discern predominant mass transfer mechanisms (vapor, product, or aqueous phases).

Pile Bent Design Criteria
M.A. Gabr and R.C. Borden
NC Department of Transportation
07/07 to 06/10
The main objective of the proposed project is to develop undercut criteria for different site conditions and provide tools for identifying depth of undercut, as well as alternative or supplemental approaches to improving soil bearing properties and workability. The approach to be developed will be supplemented with the use of expedient in situ probing technique, such as shear vane or Dynamic Cone Penetromenter (DCP), which are currently used by NCDOT but not necessarily to define undercut criteria. The research work will encompass laboratory and field work as well as modeling and analysis of data.

Comprehensive Performance Evaluation of Polymer Modified Hot Mix Asphalt Mixtures
Y.R. Kim and R.H. Borden
Korea Kumho Petrochemical Co., Ltd.
10/06 to 10/07
With the goal of accurate pavement performance evaluation, the PI and his co-workers at NCSU have been developing advanced models for hot-mix asphalt (HMA) mixtures under complex loading conditons. Over the past decade, they have been successful in developing material models that can accurately capture various critical phenomena such as: microcrack induced damage this is critical for fatigue modeling; strain rate-temperature interdependence; and viscoplastic flow that is critical for rutting evaluation The resulting model is termed the viscoelastoplastic continuum damage (VEPCD) model.

Performance-Based Mix Design For Lime-Modified Asphalt Mixtures
Y.R. Kim, R. H. Borden
Chemical Lime Company
08/06 to 12/06
The proposed research is designed to determine the optimum asphalt content of the Lsub mixture for the Charlotte lime test sections using performance testing. The performance tests to be used in this study include: Dynamic modulus tests at varying frequencies and temperatues; Direct tension tests at 5 degrees and 40 degrees C for the viscoelastoplastic continuum damage (VEPCD) model; and Triaxial repeated load permanent deformation tests at 55 degrees C.

Design Criteria for Post and Beam Bents with Drilled Shafts and Other Structures
M.J. Kowalsky and M. Gabr
NC Department of Transportation
07/05 to 06/07
The research described in this proposal aims to expand upon work currently underway for Pile-Bent bridge structures to all sub-structure systems employed by the NC Department of Transportation, including spread footings and columns supported on drilled shaft foundations. The research tasks encompass identifying issues specific to drilled shaft bent design and selection of a series of sample structures for analysis and design, as well as structural testing of bridge sub-structure to superstructure connections.

Pile Bent Design Criteria
M.J. Kowalsky and M.A. Gabr
NC Department of Transportation
$326,813
Detailed 3D analysis models will be used to provide a better understanding of the actual performance of NC Department of Transportation sub-structure systems (depth to fixity; connection performance, effective length factors). In addition, the proposed work aims at providing a rational basis for identification of key performance limit states (drift and strength limits) as well as design examples comparing LFD and LRFD criteria for bridge sub-structures.

Fuzzy Neural Network Models for Geotechnical Problems
M. Shamimur Rahman
NC Department of Transportation
07/04 to 06/07
Recently an alternative approach to modeling has emerged under the rubric of 'soft computing' with 'neural network' and 'fuzzy logic' as its main constituents. The general nature of geotechnical problems and the consequent role engineering judgments play in their treatment, make them ideally amenable to modeling through these emerging methods of modeling. The main objective of the proposed research is to: (i) develop a general framework and a computational toolbox for development of fuzzy neural network models to geotechnical problems, and (ii) to develop fuzzy neural network model for a variety of geotechnical problems of interest to NCDOT: (a) hammer approval, and (b) settlement prediction.