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Research Interests
engineering properties of soils, slope stability, hydraulics
and hydrology, logging mechanics, forest roads
Current Research
Marv Pyles continues to conduct a broad array of research, extending
from applications of classical hydraulics and hydrology, through
theoretical and experimental studies of soil shear strength and
root reinforcement, to cable logging mechanics. In Marv's words,
"I'm a problem solver, so, much of the research that I
do is directly related to an applied problem currently at the
forefront in Forest Engineering practice". Applied science
shows up clearly in Marv's work with fish passage at road stream
crossings. "The biggest bang for our buck in helping threatened
and endangered fish species is to provide access to the habitat
that currently exists. Design and construction of stream crossing
culverts to provide for free movement of fish throughout their
natural range will be costly, but it is still the most effective
use of monies intended to restore fish species". Theoretical
work can be seen in Marv's studies of soil shear strength and
the effect that roots have on soil strength. "The root
reinforcement story and its' link to landslides on steep forest
land - which is very compelling to the layman - is just full of
holes that are begging to be filled with high quality research.
There is little doubt in my mind that roots provide reinforcement
of forest soil that translates into a greater resistance to landsliding
than in non-rooted soils, however, current simple models of root
reinforcement are simply not adequate to explain when and where,
and under what circumstances roots make the difference between
a stable slope and a landslide. There is a big difference between
showing that roots can influence slope stability, and showing
the real magnitude of that influence." Logging
mechanics has always been an enjoyable application of structural
mechanics for Marv. "I have had a lot of fun over the
years adapting classical structural mechanics analysis techniques
from Civil Engineering to cable logging problems." Do
we know all that we need to know about logging mechanics? "It
is clear that good loggers know how to get the job done, but that
doesn't mean that there are not opportunities to improve practices
and most importantly, improve safety." Logging mechanics
serves as a foundation for new ideas, and for examining the safety
implications of proposed practices.
Current Programs
fish passage at low volume road crossings, analytical modeling
of tail spars and intermediated supports, failure mechanisms in
shallow forest soils, peak flow hydrology
Courses
- FE 315: Soil Engineering
- FE 316: Soil Mechanics
- FE 330: Fluid Mechanics and Hydraulics
Educational Philosophy
I believe that Engineering Education should be an appropriate
balance of basic fundamentals that will serve an engineer throughout
a professional career and current topics that have a short half-life,
and yet are essential to current practice. In general, the Engineering
Sciences, which include the courses that I teach, are lasting
fundamentals that will have application to engineering problems
many years into the future. The Engineering Sciences should dominate
any engineering program. The engineering problems that a professional
encounters change over time, but the solutions are always based
on fundamental theories and principles. Adapting fundamental theories
to solve new problems is the essence of engineering. For this
reason, I expect students to understand engineering fundamentals.
Getting the correct answer to a problem is not the test of success
in the classroom. Rather, success is understanding the problems
well enough to seek out an appropriate solution method. Along
the way, the correct answer will be forthcoming. The key to success
in my courses is understanding. You should be satisfied
with nothing less. One of the best tests of understanding
is to explain what you know and how it applies to engineering
problems. For this reason, complete work in my courses includes
thorough written documentation that explains your approach to
a problem and the method of solution. Calculations without written
narrative documentation are not acceptable in professional practice,
therefore, they are not acceptable in school.
Selected Publications
Pyles, M. R. and C.K. Lyons. 2001. Analysis of Unguyed Spar-Trees.
International Journal of Forest Engineering. 12(2).
Beschta, R. L., M.R. Pyles, A.E. Skaugset, and C.G. Surfleet.
2000. Peakflow responses to forest practices in the western cascades
of Oregon, USA. Journal of Hydrology, 233(2000): 102-120.
Pyles, M.R., P.W. Adams, R.L. Beschta, and AE Skaugset. 1998.
Forest practices and landslides. A report prepared for Governor
John Kitzhaber. Forest Engineering Department, OSU, Corvallis.
Pyles, M.R., and AE Skaugset. 1998. Landslides and forest practice
regulation in Oregon In: Environmental, Groundwater, and Engineering
Geology: Applications from Oregon, Scott Burns (ed.), Star Publishing
Co., Belmont, CA. pp. 481-488.
Bakke, P.D., and M.R. Pyles. 1997. Predictive model for nitrate
load in the Bull Run Watershed Oregon. Journal of the American
Water Resources Association, 33(4):897-906.
Nodes, J.E., M.R. Pyles, and F.R. Butruille. 1997. Repeated-load
test performance of a forest road subgrade soil at field stree
levels. Proceedings, International Symposium on Thin Pavements,
Surface Treatments, Unbound Roads, University of New Brunswick,
Fredericton, New Brunswick, Canada, June 24-25, pp. 109-116.
Pyles, M.R., K.C. Womack and H.I. Laursen. 1994. Dynamic characteristics
of a small skyline logging system with a guyed tailspar. Journal
of Forest Engineering, 6(1):35-49.
Charland, J., A.G. Hernried and M.R. Pyles. 1994. Cable Systems
with elastic supporting elements. Journal of Structural Engineering.
ASCE, 120(12):3649-3665.
Pyles, M.R., J.W. Anderson and S.G. Stafford. 1991. Capacity
of second-growth Douglas-fir and Western Hemlock stump anchors
for cable logging. Journal of Forest Engineering. 3(1):20-37.
Schoenemann, M.R. And M.R. Pyles. 1990. Statistical description
of triaxial shear test results. Geotechnical Testing Journal,
GTJODJ, 13(1):58-62.
Selected Recent Theses
Lyons, C. Kevin. 2001. Mechanical Stresses in Trees Resulting
from Strain Compatibility in an Anisotropic Material. PhD.
House, Matthew R. 2001. Countersunk Culvert Hydraulics for Upstream
Juvenile Fish Passage. MS.
Bransom, Mark. 1997. Geohydrologic conditions on a steep forested
slope: modeling transient piezometric response to precipitation.
PhD
Skaugset, Arne. 1997. Modeling root reinforcement in shallow
forest soils. PhD
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