Plan assistance and critique
Looking for some help with an idea I have and looking for suggestions/direction.
There are various areas on my local trail that have some bad sand spots. When I say bad, I mean if we haven't had rain in a while it could actually make you dismount and push your bike through. The rest of this section is fantastic, which really makes these short sandy areas a bummer. My idea was to build "bridges" over the sandy area.
I've taken a picture of some sketches I made up to get a general idea of the best way to do this. Would appreciate any input for experienced builders.
- Using fresh logs (Pine) for the bridge bases.
- Using split logs (Pine) for the planking screwed into the bases.
- Cutting the trail half the height of the log bases for the bridge to sit in. (total elevation from ground would be about 8-10 inches.
What would be recommended for cross-bracing this? I was thinking of more logs cut to the width and placed every few feet. What would be the best way to fansten them together? Is there a better option?
Can anyone provide pictures or details on the ramps for either side. I understand that a cyclist could easily lift the front wheel to get on, but this trail also sees some foot traffic from runners and explorers and I don't want to create a tripping hazard here.
re plan assistance and critque
Picking the right wood for ground contact is always a challenge, esp. in a warm climate. If you are turnpiking (putting down logs/rails and filling in with good trail tread material such as mineral soil, crushed rock etc) it doesn't matter too much if the logs or whatever rot slowly, as the tread will consolidate and work pretty well for a long time.
I've ridden in Tallahassee but nowhere else in FL so don't know your conditions. If the structure you pictured (very clearly BTW) has to sort of "float" and span a deep soft spot I wonder if you wouldn't be better off with 2X and 4X treated lumber. It would be easier to brace and nail to/through and you can get a vendor to tell you how long it should last. For transition at each end just nail on a 2X treated board, pile and tamp crushed rock against it and you should be good to go. You could add 2X sides onto the backboard slanting down to the trail grade if you want to get fancy.
Really short sections could be as narrow as 32" (32 has the magic property of going exactly 3 times into 96, and 8-ft lengths of whatever X tread material you use are readily available). Much over 24 feet and you might want to look at 60" width (same as std sidewalk in lot of places, would allow comfortable 2-way pedestrian traffic) with a 3-stringer framing approach underneath. Brace it with 2X bridging every 12 feet or so and that plus the backboards should keep everything stable.
Last edited by TFitz; 08-18-2012 at 10:09 PM.