Robert Mitchell, Geology,
Western Washington University
This is a geology course that focuses on the core activities of engineering geologists – site characterization and geologic hazard identification and mitigation. Through lectures, labs, and case study examination students learn to couple their geologic expertise with the engineering properties of rock and unconsolidated materials in the characterization of geologic sites for civil work projects and the quantification of processes such as rock slides, soil-slope stability, settlement, and liquefaction.
Lecture and lab
University with graduate programs, primarily masters programs
This is a junior-level course for geology majors and is required for the Environmental and Engineering Geology Concentration within the BS Degree in Geology. Pre-requisites include physical geology and the first course of calculus-based physics (mechanics).
This course introduces the engineering mechanics of Earth materials and how they respond to forces and stresses. The first half of the course covers rock mechanics and the process of characterizing the failure susceptibility of rock masses. Using data from case studies, students assess rock-mass quality by examining intact rock strength and rock-core designation data; plot planar discontinuity data on stereonets and perform kinematic analyses; and analyze rock-slope stability (slides and topples) by applying factor of safety equations. The second half of the course focuses on the mechanics of unconsolidated materials (soils). Students learn to apply relations that quantify processes such consolidation and settlement, compaction, soil slope stability, and liquefaction. In the solution of these problems students use geotechnical engineering methods such as the Unified Soil Classification System and testing standards established by the American Society for Testing Materials (ASTM).
Upon completion of this course students should understand:
- Site characterization and how to collect, analyze, and report geologic data using standards in engineering practice (e.g., ASTM methods).
- The fundamentals of the engineering properties of Earth materials and fluids.
- Rock mass characterization and the mechanics of planar rock slides and topples.
- Soil characterization and the Unified Soil Classification System.
- The mechanics of soils and fluids and their influence on settlement, liquefaction, and soil slope stability.
The key feature that facilitates learning in this course is coupling actual field data from case studies with analysis in a software package produced by Rocsience. Through industrial contacts I received an extensive data set from a site characterization of a rock mass along a freeway expansion in Washington State. The data set includes hundreds of discontinuity measurements, core-log data, site photos, intact rock test data, core-log photos, and borehole data. In a series of lab projects student assess the rock-mass quality, determine RQD value from core photos, examine intact rock compression test data, plot discontinuity data on stereonets, and perform a kinematic analysis using the Rocscience software—I push them toward a limited equilibrium analysis, but we aren't quite there. Students take ownership in their learning because the project is 'real' and most of them drive by the site on a frequent basis. The Rocscience software allows them to visualize the concepts, experiment with parameter sensitivity, and stretch their curiosity about the processes. Students step through the same procedure with a soil mechanics case study. A local geotechnical engineer visits the classroom and discusses multiple regional case studies—the students use data from these studies to explore settlement and rotational slide scenarios using tools in Rocscience and learn about the key 'troublesome' unconsolidated deposits in the region. I am also an advocate of ArcGIS and have designed lab projects that allow them use available digital data to characterize the geologic hazards of a potential site and research the government regulations and the policy steps required to develop the site.
This course was designed in part to develop the quantitative skills of geology students, but mainly to introduce geology students to a career option that allows them to apply their science, and, a career that satisfies the needs of the State of Washington. Although Washington State regulates the practice of Engineering Geology (through licensure), academic institutions in the state are not addressing the training of engineering geologists at the BS level. I saw this as an opportunity, because the demand for engineering geologists in Washington State is growing. Population growth, development in challenging geologic terrain, forest practices, sea-level rise, geologic hazard mitigation efforts, and government policy are increasing the demand for engineering geologists. I have a geoscience, physics, and engineering academic background, and enjoy sharing my quantitative approaches with students; thus, developing and teaching this course has been professionally gratifying.
Students in this course are assessed through lab experiences, problem sets, two quarterly exams, and a comprehensive final exam. The lab exercises and problem sets enforce the theory and develop problem solving skills and critical thinking. I do not require the memorization of equations; therefore, I provide an equation sheet that students use for the exercises and exams.
Engineering Geology Syllabus (Acrobat (PDF) 25kB Feb22 13)
References and Notes:
Coduto, D. P., (1999) Geotechnical Engieering: Principles and Practice, Prentice Hall, Inc.
Additional references include:
Sabatini, P. J., Bachus, R. C., Mayne, P. W., Schneider, T. E., Zettler, T. E., FHWA-IF-02-034, 2002, Evaluation of soil and rock properties, Geotechnical Engineering Circular No. 5. (http://isddc.dot.gov/OLPFiles/FHWA/010549.pdf).
Washington Department of Transportation, Geotechnical Design Manual, Publication No. M 46-03 (http://www.wsdot.wa.gov/publications/manuals/m46-03.htm).