Terrain Dynamics for Trail Folks

2 Day Workshop- Day 1 in classroom, day 2 in the field.
Dates: Sunday, March 17 & Monday, March 18, 2019
(lunch provided both days)
Cost: $300
Michael Shields, 
Michael D. Shields Consulting, PTBA Member
Alex Man, PhD, PEng, Scatliff+Miller+Murray


A 2-day in-depth look at the variable nature and basic mechanics of the ground we build trails across, including the potential snares hidden within it. Treats that ground as a dynamic “structure” and covers slope stability factors (including on “flat ground”); soil mechanics (deposition mechanisms, granulation, density and porosity, internal friction, rock/gravel content, organics, soil chemistry, soil moisture); terrain hydrology (water entry, surface and subsurface water movement, drainage area, flat ground drainage, sheet vs channeled flow, the effects of freeze/thaw, “toe of slope” accumulations, “drainable edges” in topography); the role of bedrock (simplified rock mechanics) and vegetation; all these factors in combination; surface indicators of subsurface phenomena; and using this knowledge in the selection of trail routes, grades, structures and drainage systems that work. Includes classroom and field exercises, and a binder of reference material.


1. Awareness of the complexity of the ground we build trails on, and the variety of forces influencing trail “sustainability”.

2. Ability to sample and analyze soils in the field, and at least generally predict their performance under traffic loads over time.

3. Ability to recognize surface indicators of subsurface conditions and trends.