Geotechnical / Geoenvironmental Engineering

Research Project Abstracts: 2002 - 2003

Development of Permeable Reactive Barriers (PRBs) using Edible Oils
R. C. Borden
Department of Defense, SERDP
01/01 to 01/05
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. Evaluate the performance of these procedures in a series of year long continuous flow column experiments; 4) Modify the model RT3D to simulate the major processes controlling the performance of edible oil barriers. Use this model to identify alternative barrier configurations and injection procedures to improve barrier performance and reduce costs.

Use of Soybean Oil and Soybean Products for Groundwater Bioremediation
R. C. Borden
United Soybean Board
04/02 to12/02
Emulsified soybean oil can be used to treat groundwater contaminated with a variety of pollutants including rocket fuel, heavy metals, acid mine drainage and nitrate from agricultural and waste management operations. The objective of this proposal is to evaluate the use of soybean oil and soy-based products for use in treating these pollutants.
1. Construct and monitor batch laboratory incubations to evaluate the potential of several different soybean products to enhance biodegradation and/or immobilization of four major types of pollutants: (1) nitrate; (2) perchlorate; (3) chromium; and (4) acid mine drainage.
2. Evaluate the in-situ treatment efficiency of these materials in laboratory scale columns,
3. Compare the cost and effectiveness of this technology to alternative approaches for aquifer remediation.

A Unified Approach to Predicting Long Term Performance of Asphalt-Aggregate Mixtures
Y.R. Kim, R.H. Borden and Y. Horie
National Science Foundation
09/98 to 12/02
The research objective is to develop test methods and models for predicting long term performance of asphalt concrete that can account for viscoelasticity, damage, volumetric/deviatoric coupling, temperature, and aging. The objective will be accomplished by applying the elastic-viscoelastic correspondence principle and the continuum damage theory. The constitutive model will be incorporated into the ABAQUS finite element code, and used to predict the response and performance of laboratory pavements loaded by the Model Mobile Load Simulator. Nondestructive surface wave tests will be performed to determine the change in material properties due to fatigue damage growth.

Jetting Techniques for Pile Installation and Environmental Impact Minimization
M. A. Gabr
NC Department of Transportation
07/02 to 06/04
The objective of this research is to characterize and define disturbance due to jetting installation method as manifested by zone of influence and volume of debris area. This disturbance will be defined as a function of jetting pressure, flow rate, and site conditions including soil types. Second, specifications will be developed with recommendations regarding jetting parameters to minimize disturbance as well as possible conjugate practice modification of the jetting procedure such as addition of vacuum and/or water extraction/ circulation techniques. Ecological impacts of jetting will be presented in terms of the jetting disturbance effect on the hydric soils. Accordingly, and depending on the specific site inventory for different regions of North Carolina, the impact of disturbing the hydric soil layer on aquatic and vegetative ecosystems can be evaluated using established assessment techniques.

Vacuum-Enhanced Flushing of Cesium Using the Well Injection Depth Extraction (WIDE) Deployment at the Battelle Columbus Laboratories Decommissioning Project
M. A. Gabr
Battelle/US DOE
08/02 to 04/03
The overall objective of this project is to deploy the WIDE technology for soil flushing of subsurface contaminants at the Battelle Columbus Laboratories Decommissioning Project (BCLDP) West Jefferson facility's middle site filter bed. When the abandoned filter beds were replaced the water tiles and much of the contaminated sand and gravels were removed leaving only the soluble isotopes.

Internet-Enabled Laboratory Experiences for Undergraduate Civil Engineering Students
V.C. Matzen, M. Gabr and A. Gupta
National Science Foundation CCLI program
06/01/03 to 05/31/05
This proposal is aimed at adaptation of recent developments in information technology for incorporation of internet-enabled civil engineering laboratory experiments in undergraduate structures and geotechnical courses. Faculty and students will be able to remotely access, run, and control these experiments either independently or in a classroom setting. Such a capability would facilitate the offering of these courses via distance learning program to provide opportunities for "non-traditional" students (e.g., part-time student, working parent, and career-changing adult) seeking careers in Civil Engineering. Implementation of this work will lead to enhancing the quality of undergraduate Civil Engineering courses and making laboratory curriculum widely accessible.

Lateral Capacity of Drilled Shafts Embedded in Soft Weathered Rock
M. A. Gabr and R. H. Borden
NC Department of Transportation
07/01 to 07/02
The overall objective of ongoing research is to define the shape and magnitude of the P-y curves appropriate for use in designing deep foundation to resist lateral loads in the Piedmont soft weathered rock profiles and to develop systematic design procedure for these types of foundations. Emphasis will be placed on performing additional field tests to investigate shaft embedment in soft rock based on a deformation criterion, while maintaining an acceptable level of safety. The results of the additional field tests, laboratory tests, as well as the rock dilatometer tests, will be used to verify the P-y design model and demonstrate the validity of the developed analysis/design procedure.

Translation of Scanned Data Into Finite Element Meshes
D. F. Laefer
North Carolina State University
06/03 to 05/04
Pioneering the translation of scanned data into finite element meshes for the purpose of facilitating the analysis of existing structures. Using the data from Low Library to create three-dimensional opportunities for the application of differential displacements to determine allowable movements.

Translation of Scanned Data into Finite Element Meshes
D. F. Laefer
Robert Silman Assoc., PCA
03/02 to 05/03
Pioneering the translation of scanned data into finite element meshes for the purpose of facilitating the analysis of existing structures. Using the data from Low Library to create three-dimensional opportunities for the application of differential displacements to determine allowable movements.

Rehabilitation of Existing Pile Groups in Clay using Innovative Ground Iimprovement Techniques
D. F. Laefer
Unsponsored
2002, ongoing
Pile reuse is a key component of sustainability. Having a reliable design methodology with which to do this is a critical component. For this the concept of superposition is proposed. The current research uses small and large laboratory tests to investigate the reliability of such a design methodology.

New Shear and Tensile Testing Procedures for Low Strength Masonry
D. F. Laefer
Unsponsored
2002, ongoing
Developing new shear and tensile tests for low strength masonry for the purpose of demonstrating high levels of variability of historic structures,

Freezing as an Alternative to Rock Blasting
D. F. Laefer
Unsponsored
2002, ongoing
Increasingly communities are banning blasting. This work investigates the viability of modifying traditional freezing techniques for the commercial removal of rock and old concrete.

Impact of Clay Inclusions on Early Soilcrete Strength
D. F. Laefer
Unsponsored
2002, ongoing
Small amounts of clay in cement grouts . This investigation considers whether there is the same dramatic compressive strength loss in jet grouted mixes.

Management Information Systems for Pre- and Post-incident Hazard Assessment
D. F. Laefer
Unsponsored
2001, ongoing
Creating a seamlessly integrated management information system with GIS, CAD, and relational databases for pre-and post-incident hazard assessment for urban areas using the World Trade Center September 11, 2001 data.

Expansion Quantification of Soundless Demolition Materials
D. F. Laefer
Unsponsored
2002, ongoing
Devising meaningful laboratory tests for soundless demolition materials to quantify the expansion characteristics of the material.

Subsurface and Surface Soil Movements due to Tunneling in Seoul
D. F. Laefer
Unsponsored
2002, ongoing
Using collected field data for tunnel lining and surface changes, analysis of below ground and surface soil movements due to tunneling in Seoul is being done.

Somerset Plantation Building Settlement
D. F. Laefer
Unsponsored
2001, ongoing
Somerset plantation is a national historic landmark located in northeastern North Carolina and is the largest extent plantation in the state. The main house and many of the smaller, outlying buildings are currently exhibiting distress. At many locations, there is sufficient differential settlement to impact building functionality (inoperable doors and windows and sidewalk collapse). Heavy visitor traffic was proposed by the site staff as the cause of the building displacements. Site investigation identified a change in the ground water table as the probable cause of building movement. Two potential sources of ground water change are currently being investigated -- water level management of an adjacent lake and a nearby mining operation.

The Problem of Unknown Foundation: An Exploratory Study and Recommendation
M. S. Rahman
NC Department of Transportation (Technical Assistance)
01/0 to 03/03
A large number of bridges in North Carolina are primarily supported by piles or shallow foundations. The years of scour have caused significant changes in their embedment depth leading to substantial reduction in their load carrying capacity. For many old bridges, often the records of foundations do not exist and a great deal of uncertainty in relation to foundation subsurface geometry and condition. There is an urgent need for reliable and accurate predictive tools to solve these problems of unknown foundation.. This brief study presents: (i) a preliminary review of literature, (ii) an evaluation of the difficulties associated with the current method being used by NCDOT, (iii) an exploratory study to evaluate the potential of wavelet analysis to process the data from NDT, and (iv) recommendation for a comprehensive study for the problem of unknown foundation.

Traffic Barrier Deflection Under Vehicular Impacts
M. S. Rahman
NC Department of Transportation (Technical Assistance)
06/02 to 08/02
The North Carolina Department of Transportation (NCDOT) has been using several types of traffic barrier. Recently on the basis of a crash test, a specific barrier was accepted by FHWA. However, there exist some concerns about the currently adopted 'minimum back distance' between the barriers and an edge or another working zone. Of course this distance should be governed by a realistic estimate of the maximum displacement of the barrier under an anticipated vehicle impact. It is certainly desirable to minimize this back distance with the constraint of required safety. In this study we looked into the available bases for estimating the above mentioned maximum barrier displacement under the impact loading of an errant vehicle. A comprehensive review was done including the literature on both crash tests and computer based simulation. On the basis of this study, a research proposal was submitted to NCDOT.

Load and Resistance Factor Design (LRFD) for Reliability Analysis/Design of Driven Piles Axial Capacity
M. S. Rahman and M.A. Gabr
NC Department of Transportation
07/01 to 12/02
The main objective of this study is to develop the resistance factors for the design of driven piles in North Carolina. These factors are being developed for the unique soil types of various regions of North Carolina. The development of these factors are being attempted in the framework of 'advanced reliability analysis' using the results from Pile Driving Analyzer (PDA) and static load test data embodying the uncertainty associated with soil parameters. The results from this study will lead to an implementation of the Load and Resistance Factor Design (LRFD) for piles, bringing NCDOT in compliance with AASHTO guidelines.

A Mechanistic Approach to Evaluate Contribution of Prime and Tack Coats in Composite Asphalt Concrete Pavements
A. A. Tayebali and S. Rahman
NC Department of Transportation (NCDOT)
7/00 to 6/03
The importance of proper AC layer interface bonding cannot be overemphasized for good performance of AC pavements. A strong bonding between layers is critical to dissipate shear stresses into the entire pavement structure. On the other hand, lack of bonding may cause slippage phenomenon and activate distress mechanisms that will rapidly lead to total failure of the pavement. The objective of this study is to evaluate the effects of different prime and tack coats on the bond strength in relation to the thickness of the asphalt concrete layer. In particular, the distribution and dissipation of shear stresses under traffic loading and how they effect the interlayer bonding will be studied. Based on the results of the study, correlation will be developed between delamination parameters and stress-strain-displacement field.

Soft Computing for Geotechnical Problems
M. S. Rahman
Unsponsored
07/97 to 12/02
Uncertainty, imprecision, complexity, and nonlinearity are inherent in many geotechnical problems. The conventional modeling of the underlying systems becomes quite difficult. Recently a new approach to modeling has emerged under the rubric of 'soft computing'. This consists of many complementary tools: fuzzy logic, neural network, probabilistic reasoning, genetic algorithm and others. Among these, neural networks can handle complexity and nonlinearity, while fuzzy logic provides a rational framework to incorporate imprecision. In this research program, applications of 'soft computing' are being developed for some important geotechnical problems.

Wave-seabed Interaction
M. S. Rahman
Unsponsored
06/96 to 12/02
Water waves propagating on the ocean creates a cyclic pressure on the ocean floor that may be significant in shallow water. This in turn induces stress and pore pressure fields in fluid-saturated seabed, which can cause instability in the seabed. The general theme of this ongoing research program has been to understand the mechanism of wave-induced seabed response and instability, and to develop predictive analytical tool to study this problem. At present, the following specific problems are being studied: (i) effects of inertial forces on wave-induced seabed response, (ii) wave-induced response of seabed containing a gas-laden layer, and (iii) development of a simple analysis for the coupled flow and inelastic deformation of seabed including the pore water pressure generation under cyclic loading.