Geotechnical Engineering

 

• Introduction
• Research
• Faculty
• Facilities and Resources
• Courses
• Qualifying Exam

 

 

Program Coordinator:
Charles D. Shackelford
shackel@engr.colostate.edu
(970) 491-5051

 

Introduction

Geotechnical Engineering focuses on the study, design, and use of natural geomaterials (soil and rock), geosynthetic (polymer) materials, and other types of man-made materials (industrial by-products with potential for use in engineering applications).  Geotechnical Engineering employs concepts of soil and rock mechanics to the analysis and design of geotechnical structures such as (i) shallow and deep foundations, (ii) retaining walls and structures, (iii) excavations and excavated slopes, (iv) earth dams and embankments, and (v) liners and covers for waste containment facilities (e.g., landfills).  Since an advanced degree normally is required for engineers working in this field, the program prepares students to solve complex geotechnical problems based on a fundamental understanding of geomaterial behavior and use of modern tools for geotechnical design and analysis.  State-of-the-art computing and experimental facilities are used extensively in the teaching and research conducted by faculty and students.
Graduate studies in Geotechnical Engineering typically consider issues like the following:

• Advanced experimental methods for laboratory testing of geomaterials
• Beneficial use of waste materials
• Characterization of the mechanical behavior of geomaterials
• Constitutive modeling of geomaterials
• Development of new materials for geotechnical engineering applications
• Earth fills and tailings dams
• Expansive soils
• Foundation design and analysis
• Geotechnical earthquake engineering
• Hydraulic conductivity of geomaterials
• In situ testing of geomaterials
• Liquefaction induced by earthquakes and explosives
• Slope stability and earth-retaining structures
• Unsaturated soils

 

Research

Current research interests and activities of Geotechnical Engineering faculty at CSU are performed in a variety of areas, from fundamental to applied research, and from experimental to theoretical research.

Fundamental research includes basic aspects of soil mechanics, such as the experimental determination of the physical and mechanical properties of geological, geosynthetic, and waste materials used in civil engineering applications under both saturated and unsaturated conditions.  Examples of fundamental research activities in Geotechnical Engineering at CSU include the determination of the physical and mechanical properties of expansive, collapsible, residual and cemented soils, sands containing fines, and soil-bentonite backfills used in vertical cutoff walls.  Other fundamental research is focused on:

• the development of new materials (e.g. rubber-soil mixtures and fiber-reinforced soils) for stabilization of slopes, embankments and foundations;
• design of shallow foundations and pavement subgrades;
• evaluation of the liquefaction potential of transitional soils;
• characterization of the stress-strain response of soils using hollow-cylinder and triaxial apparatuses;
• evaluation of the effect of principal stress rotation and intermediate principal stress on the stress-strain response of soils;
• determination of the effect of soil fabric and anisotropy on soil behavior;
• evaluation of contaminant transport through fine-grained materials used as waste containment barriers (e.g., compacted clay liners, geosynthetic clay liners, and soil-bentonite backfills for vertical cutoff walls);
• and evaluation of the effects of interactions between pore fluids other than water (e.g., contaminant solutions) on the properties of fine-grained barrier materials.

Applied research refers to studies that are directly applicable to engineering practice.  Examples of applied research in Geotechnical Engineering at CSU include the evaluation of the use of helical piers as foundations for structures resting on expansive soils, evaluation of blast induced liquefaction of soils surrounding hardened missile silos, and dam safety analysis for existing earthen dams subjected to earthquake loading.

Experimental research is performed at both the laboratory and the field scales.  Laboratory experimental research typically is associated with the fundamental characterization of geomaterials, whereas field experimental research is more typically applied research.

Theoretical research pertains to the development of new theories to describe the fundamental behavior of geomaterials or the evaluation of existing theories of geomaterial behavior, typically expressed in the form of analytical or numerical models.  Examples of theoretical research in Geotechnical Engineering at CSU include computer applications in geotechnical engineering, analysis of soil resistance during cone penetration, soil fabric modeling, modeling and analysis of dynamic soil-structure interaction, modeling unsaturated water flow through soil covers for landfills and waste containment facilities, and coupled flux modeling of flow and solute transport through engineered clay barriers.

 

Faculty

The following faculty members are part of Colorado State University's Geotechnical Engineering Program:  

Antonio Carraro, Assistant Professor
Wayne Charlie, Professor
John Nelson, Emeritus Professor
Charles Shackelford, Professor
Thomas Siller, Associate Dean and Associate Professor

 

Facilities and Resources

The Geotechnical Engineering program has several facilities and resources to enhance graduate studies and research.  Laboratory facilities include the Geotechnical Engineering Teaching Laboratory in the Glover Building and the recently-renovated Geotechnical Engineering Research Laboratory in the Engineering Building, which includes world-class testing devices such as Hollow Cylinder, Triaxial, and Bender Element equipment and capabilities for testing of unsaturated soils.  Research facilities also include Expansive Soils Test Site, including a large-scale, 139-m2 simulated slab on grade that is fully instrumented to measure soil suction, water content at various depths and surface heave, and four fully instrumented full-scale drilled straight shaft piers 8-m deep.

Students have access to state-of-the-art computing facilities for numerical modeling and data analysis.  Additional computing resources are available from Engineering Network Services, who maintain several computer laboratories in the Engineering building as well as centralized networks and grids on workstations that are capable of processing very computationally intensive procedures.

 

Courses

Students entering the Geotechnical Engineering program are expected to have a Bachelor of Science degree in Civil Engineering from an accredited undergraduate program.  Students can be admitted without this prerequisite, but additional background courses will have to be taken that will not count as part of the credits required for their graduate program.  The following courses are offered by this program:

	CIVE550 (3)	Foundation Engineering
	CIVE553 (3)	Slope Stability and Retaining Structures
	CIVE556 (3)	Seepage and Earth Dams
	*CIVE580 (3)	Soil Stabilization Using Sustainable Materials
	CIVE654 (3)	Experimental Soil Mechanics
	CIVE655 (3)	Advanced Soil Mechanics
	CIVE751 (3)	Soil Dynamics
	CIVE754(3)	Special Topics in Geotechnical Engineering
		(previous offerings include:  Foundation Design in Expansive Soils, Unsaturated Soil Mechanics, etc.)
	* denotes temporary course number

The curriculum for the graduate Geotechnical Engineering program is generally flexible and allows students to choose from a wide range of courses in various areas other than geotechnical engineering such as geo-environmental engineering, structural mechanics, geological sciences, soil science, mathematics, and statistics.  The curriculum is tailored to the student's desires and needs based on their thesis or dissertation research.

The Master of Science (Plan A) degree requires a research thesis and is primarily for students who plan to continue their studies toward a Ph.D. degree.  The M.S. (Plan B) degree requires a professional-related independent study rather than a thesis and is intended for students who plan to enter design/analysis careers after completing their M.S. program of study.  The Ph.D. degree is for students who are seeking a career in academia or in research.

 

PhD Qualifying Exam

The PhD Qualifying exam in the Geotechnical Engineering program is administered by the student’s PhD thesis committee and consists of both written and oral components.  For the written component, which is administered first, each committee member is asked to submit 2-4 questions/problems to the student’s advisor which are then assembled into a single written exam.  The student then schedules with her/his advisor an 8-h period over which the written exam is taken.  The written exam then is graded by the committee members, and a follow-up oral component of the exam is scheduled approximately 1-2 weeks after the written exam.  The final determination of the student's performance on the exam is based on the combined results of both the written and oral components.