1. Teaching Geology to Civil, Architectural, and Environmental Engineering Students
Patricia Gallagher, Ph.D., P.E. and Robert Swan
Civil, Architectural and Environmental Engineering, Drexel University
Earth Educators Rendezvous
July

2. Welcome to my favorite class!
I might be an engineer, but I LOVE geology

3. Background Drexel is a quarter school with a 5-year co-op program
Years 1 & 5: attend classes F, W, S quarters
Years 2, 3, & 4: rotate 6 months of classes with 6 months of employment
Quarters are 10 weeks long
Ten weeks is a very short time for students to learn everything they need to know about geology!!!

4. Geologic Principles for CAE Engineers
Text: Geology for Engineers & Environmental Scientists (Kehew)
Four credit hours (quarter system)
Two lectures (80 minutes)
One lab (120 minutes) – meets in classroom with all students!
Students are 3rd or 4th year
Civil & architectural students have taken or are taking mechanics & construction materials.
Environmental students don’t take either mechanics or construction materials

5. Objectives
Explain all aspects of the geologic cycle, including igneous, sedimentary and metamorphic rock forming processes, tectonic processes, and weathering and erosion processes.
Identify and distinguish between igneous, metamorphic, and sedimentary rocks and explain how the inherent properties of each rock type influence the engineering properties of the rock.
Explain how the engineering properties of geologic materials influence the design, construction, and maintenance of infrastructure and environmental projects

6. Objectives
Explain how infrastructure projects are influenced by their topographic, hydrologic, surficial soil and underlying geologic settings.
Interpret rock testing data and do basic stress-strain calculations using that data.
Learn geologic and agronomic nomenclature and use it to interpret published reports, surveys and maps.
Acquire background for further concrete, hydrology, environmental, and geotechnical study

7. How do we teach about engineering properties?
Minerals and Rocks
Focus on the intrinsic properties of minerals and rocks & how those properties influence the engineering properties
Crystalline vs clastic rocks
Formation processes and how they influence mechanical properties
Assignments focus on the origin of construction materials
Concrete
Steel
Brick

8. Example: Engineering in Different Types of Rocks
Different types of rocks vary greatly in suitability for different engineering projects
Questions to ask/answer:
What types of rocks are present?
How are they distributed?
How have the rocks been changed or altered?

9. Example: Engineering in Sedimentary Rocks
Difficult to generalize 
Wide range in lithology
Wide range in degree of lithification
ENGINEERING PROPERTIES VARY BASED ON ORIENTATION OF BEDDING PLANES AND OTHER SEDIMENTARY STRUCTURES

10. Example: Important Considerations for Engineering in Sedimentary Rocks
Bedding orientation
Direction and amount of slope critical
Horizontal bedding good
Bedding parallel to downslope angle of slope BAD!
Cementation:
Well-cemented sandstones & limestones usually okay for foundation support & excavations
but watch out for water infiltration in limestone, as it can lead to KARST formation

11. Example: Difficulties with Engineering in Sedimentary Rocks
Engineering properties CHANGE after deposition/lithification
Strength may increase after compaction, cementation
Strength may decrease upon weathering (shales are especially susceptible because they weather to clay minerals)
FRACTURES, JOINTS, DISCONTINUITIES WEAKEN ROCK & INCREASE FLOW OF WATER

12. Example: Engineering in Sedimentary Rocks
Typical exam question: Select 2 considerations related to engineering in the following material:
A highway road cut through shale with bedding inclined at 35° from the horizontal (see sketch below). (Choose the best two answers)
Usually strong with few limitations for construction
Bedding planes act as zones of weakness
Slopes cut parallel to bedding planes may be problematic and need rock bolts; slopes perpendicular to bedding planes should have adequate stability
Strength depends on cementation, particle size and shape, and particle mineralogy
Dashed lines indicate proposed cut slopes,
solid lines indicate bedding planes

13. How do we teach about engineering properties?
Rock mechanics
Stress-strain behavior of rocks
Rock testing & analysis of results
Engineering classification of rocks and rock materials
Factors affecting the strength of the rock mass as compared to intact specimens
Assignments and labs focus on analysis of rock core data to calculate rock quality designation, modulus ratio and rock mass rating
Stress strain behavior: nonlinear behavior; plastic vs ductile, effect of confining pressure & temperature, influence of asperities on strength
Rock testing: unconfined compression, direct shear, unconfined compression, Brazilian tensile, Mohr’s circle
Discontinuities, weathering, defects,

14. How do we teach about engineering properties?
Rock mechanics
Assignments and labs where rock core data is analyzed to calculate rock quality designation, modulus ratio and rock mass rating
Unconfined compression
Triaxial compression - gneiss
Mohr’s circle- gneiss
Calculate unconfined compressive strength, tangent modulus, modulus ratio, shear strength,
Use triaxial results to calculate unconfined compressive strength and compare results with actual test results
RQD, RMR
𝜎a= 𝐹𝑜𝑟𝑐𝑒 𝐴𝑟𝑒𝑎
∈=change in length/initial length
Et50=σa 50%ϵ
Mr=Et50/σa
𝜎3=𝑚𝑖𝑛𝑜𝑟 𝑝𝑟𝑖𝑛𝑐𝑖𝑝𝑎𝑙 𝑠𝑡𝑟𝑒𝑠𝑠 
𝜎1=𝑚𝑎𝑗𝑜𝑟 𝑝𝑟𝑖𝑛𝑐𝑖𝑝𝑎𝑙 𝑠𝑡𝑟𝑒𝑠𝑠= 𝜎3 +𝛥𝑃 
𝛥𝑃=𝑑𝑒𝑣𝑖𝑎𝑡𝑜𝑟 𝑠𝑡𝑟𝑒𝑠𝑠 
𝜏=𝑐+ 𝜎
σa = 2 C tan (45 + 𝛷 2 )

15. How do we teach about engineering properties?
Structural geology
Focus on the discontinuities in rock masses and their influence on the strength, settlement and permeability characteristics of the rock mass
Use case histories (e.g. dams and dam disasters) to illustrate how to engineer in different types of rock

16. How do we teach about engineering properties?
Earthquakes and earthquake engineering
Focus on site response (i.e. soft soil versus rock) to earthquake motion
Overview of designing earthquake- resilient structures
Structural damage intensity for different height buildings related to depth of soil and fundamental period of soil. Tall buildings sustain maximum damage when constructed on long-period soil deposits (after Kehew, 2006)
Increasing fundamental period of soil

17. How do we teach about engineering properties?
Geomorphology
For different landforms, we use the following approach:
Geology 
geologic processes/weathering 
specific landform 
soils/rocks 
engineering information/potential problems at a site

18. Where do we go from here?
We are currently in the process of flipping the class
Main topic areas
Introduction
Rocks and Minerals
Structural Geology
Geomorphology
Inaugural offering of flipped class: Winter 2017

19. Questions?