Terrain Dynamics for Trail Folks
2 Day Workshop
Dates: Saturday, March 24 & Sunday, March 25, 2017 (lunch provided both days)
Instructor: Michael Shields, Michael D. Shields Consulting, PTBA Member
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; considered foundational to any trail design class. 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. Understand the interplay of soils, water, slope angle, bedrock, vegetation, weather, altitude and latitude in establishing any terrain’s long-term suitability for any particular trail.
2. Understand the importance of surface indicators of subsurface conditions, and soil sampling, in assessing any terrain’s stability and durability, and know what to look for in those indicators/samples.
3. Appreciate the fact that the terrain is our “client” just like the trail user, but having far more latent power and patience than those users; ignore that at your peril.
Day #1 in classroom, 8:00 am to 4:00 pm (lunch provided)
Day #2 in the field (Resort grounds – we can walk), 8:30 am to 4:00 pm (lunch provided)