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Department of Forest Engineering
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Marv Pyles

 

 

Marvin R. Pyles


Professor
Gene D. Knudson Chair in Forestry

Registered Professional Civil Engineer:
California and Oregon
BS, 1973 Oregon State University
MS, 1975 Oregon State University
PhD, 1981 University of California, Berkeley
Email:

 

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 101: Introduction to Forest Engineering
  • FE 315: Soil Engineering
  • FE 316: Soil Mechanics
  • FE 330: Fluid Mechanics and Hydraulics
  • FE 480: Forest Engineering Practice and Professionalism

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

Boston, Kevin, Marvin R. Pyles, and Andrea Bord. 2008. “Compaction of Forest Roads in Northwestern Oregon – Room for Improvement.” International Journal of Forest Engineering 19(1):24-28.

Pyles, Marvin R. and Robert A. Douglas. 2007. “Inappropriate productivity measures: the demise of university forestry programs?” Forest Products Journal.

Pyles, Marvin R. and Mari Kramer. 2006. “A Case Study of DEM Based Slope Stability Assessment on Managed Forest Land in the Oregon Coast Range.” Western Journal of Applied Forestry, 21(4):195-102.

House, Matthew R., Marvin R. Pyles, and Dale White. 2005. “Velocity Distributions in Streambed Simulation Culverts Used for Fish Passage.” Journal of the American Water Resources Association [JAWRA], 41(1):209-217.

Pyles, Marvin R., 2005. “Monitoring: Its our Job from Beginning to End.” Proceedings of the COFE, HSU, 2005.

Appt, Jeremy, Arne Skaugset, Marvin Pyles, and Michael Wing. 2003. “Discriminating between Landslide Sites and Adjacent Terrain Using Topographic Variables.” Hydrological Science and Technology, American Institute of Hydrology, Vol. 19, Number 1-4, 2003. pp 363-374.

Kirkham, Tracie, and Marvin Pyles. 2003. “Seasonal Mechanisms of Peak flows and Flood Frequency at Reynolds Creek, Idaho.” Hydrological Science and Technology, American Institute of Hydrology, Vol. 19, Number 1-4, 2003. pp 267-276.

Pyles, M.R. and K. Lyons. 2001. “Analysis of Unguyed Spar-Trees.” International Journal of Forest Engineering. Vol.12, No.2, July 2001.

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, Marvin R. 2000. “Occurrence of Landslides on Forest Land: the devil is in the details.” Proceedings of Summit 2000 – Washington Private Forest Forum. University of Washington, College of Forest Resources, March 29-30, 2000, Olympia, WA. 8p.

Bakke, Paul D. and Marvin 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.

Charland, James, Alan G. Hernried, and Marvin R. Pyles. 1994. “Cable Systems with Elastic Supporting Elements.” Journal of Structural Engineering, ASCE, 120(12):3649-3665.

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.

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):29-37.

Commandeur, Paul R. and Marvin R. Pyles. 1991. “Modulus of Elasticity and Tensile Strength of Douglas-fir Roots.” Canadian Journal of Forest Research, 21:48-52.

Schoenemann, Mark R. and Marvin R. Pyles. 1990. “Statistical Description of Triaxial Shear Test Results.” Geotechnical Testing Journal, GTJODJ, 13(1):58-62.

 

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