Big Park Loop Trail - Friends of the Forest - 6.3.11
I replaced some old rock check steps with some more bike friendly rock structures with the Friends of the Forest today. These pictures are always difficult to judge. Big Park Loop trail is a beginner loop and these structures keep it simple but fun.
Rock Armoring - Boulder Causeway
On Friday I spent my day constructing a boulder causeway for a short reroute of the Broken Arrow Trail in Sedona. We are building this little rock structure to one, make a nice feature, and two create a hardened tread where it might otherwise erode. Here are a few photos and I'll add some more of the final product.
Trail Construction - Rules for Rock Work
1. Gravity - Rocks should not move out of place by the forces of gravity. A rock wall should be leaning into the hillside for instance.
2. High and Outside - Rocks should make contact with other rocks at their highest points and on the outer side of a wall. This not only keeps all the soil and crush retained behind the structure but also keeps the rock from pivoting.
3. Two Points - Two or more points of contact between rocks is important to keep them in place.
4. Crush - Gaps should be filled with rock, not soil. Rock encourages drainage and cannot compact over time. Make the crush at the spot to be packed with rock if possible and break it up until you have a mix of sizes from softball to ping pong ball. A mixture of sizes will pack best.
5. Start Low and Bury It - Rock structures often fail when the soil supporting the rock is washed out. Rocks that are well placed are often buried 2/3rds of the way in the soil to prevent this. The first step or tier of a wall should be almost entirely buried. These keystones are the most important part of the structure and need to provide a good foundation.
6. Aesthetics - Rock structures in the tread should be a positive control by encouraging the user in a certain way. A step should never force someone in an alternate route.
7. Gargoyles - Don't let them go around your structure. This includes users and water. These rocks, gargoyles, should funnel everything through your structure if it is a step for instance. They also must follow all of the above rules even if they are outside of the primary walking surface.
8. Find the Bottom - Find how the rock wants to naturally sit. Move it around and find its center of gravity. Limit how much you prop it up and never prop it up on the outside where that little wedge rock can fall out.
9. Use Big Rocks - Big rocks don't move as easily. If you can lift it, it might be too small. Small rocks can work, but need to be perfectly placed to last.
10. Rule 1 is the only rule that cannot be ignored if the worker has the appropriate experience and skills for the project.
2. High and Outside - Rocks should make contact with other rocks at their highest points and on the outer side of a wall. This not only keeps all the soil and crush retained behind the structure but also keeps the rock from pivoting.
3. Two Points - Two or more points of contact between rocks is important to keep them in place.
4. Crush - Gaps should be filled with rock, not soil. Rock encourages drainage and cannot compact over time. Make the crush at the spot to be packed with rock if possible and break it up until you have a mix of sizes from softball to ping pong ball. A mixture of sizes will pack best.
5. Start Low and Bury It - Rock structures often fail when the soil supporting the rock is washed out. Rocks that are well placed are often buried 2/3rds of the way in the soil to prevent this. The first step or tier of a wall should be almost entirely buried. These keystones are the most important part of the structure and need to provide a good foundation.
6. Aesthetics - Rock structures in the tread should be a positive control by encouraging the user in a certain way. A step should never force someone in an alternate route.
7. Gargoyles - Don't let them go around your structure. This includes users and water. These rocks, gargoyles, should funnel everything through your structure if it is a step for instance. They also must follow all of the above rules even if they are outside of the primary walking surface.
8. Find the Bottom - Find how the rock wants to naturally sit. Move it around and find its center of gravity. Limit how much you prop it up and never prop it up on the outside where that little wedge rock can fall out.
9. Use Big Rocks - Big rocks don't move as easily. If you can lift it, it might be too small. Small rocks can work, but need to be perfectly placed to last.
10. Rule 1 is the only rule that cannot be ignored if the worker has the appropriate experience and skills for the project.
Huckaby Trail Armoring - Stone Pitching
I recently worked with a CREC crew to install some armoring on the Huckaby Trail in Sedona. This project spot is located where Huckaby Trail heads up the hill from Oak Creek. This armoring style is called stone pitching. Simply explained, the rocks are placed on end and tightly fitted. All holes are filled with small rock crush.
