Problem: Gravel is slowly shifting and falling off the sides.

Objective: Prevent whistle from getting squished, prevent dips in gravel.

Quick Notes:

• Gravel & whistle installed about 5 months ago
• The whistle is about 16' long
• Driven over about 10-20 times per day

Options I can think of:

1. Convert apron to concrete or asphalt (that would make the city happy)
2. Extend culvert, and pour concrete sides to retain the concrete and widen apron

Surely people with gravel driveways have overcome this problem... If this was your driveway, what would you do? What are some other options?

 

If it were my driveway, I would remove the gravel, dig down about 4 to 6 inches, put the gravel back, add sand & install pavers.

 

I prefer concrete for this type of application. If the vertical profile allows, leave a thin layer of gravel over the culvert, compact gravel everywhere, and pour a concrete apron at least 5" thick over the culvert. If the grade is too tight, remove all of the gravel backfill around the pipe and pour solid concrete around it, contiguous with the apron. Use No. 4 rebar, 4' long and spaced every foot or so, bridging the culvert and located in the center of the apron depth, tied together with longitudinal No. 4s on the ends of the transverse stub bars (in effect, making a rebar "ladder"). And pour some tapered concrete end sections to promote better drainage and prevent "piping" during a major storm event. Or pretty it up and use larger rubble rock to form the ends, set on (embedded in) concrete bases. If you're not into pretty, use the prefabricated galvanized steel end sections. Just don't make it too good, or all the neighbors will want you to do theirs.

It may sound like a lot of work, but when finished you can walk away from it and forget about it for the duration of your time on this planet. No maintenance, no settlement or deflections, and (if properly reinforced) it will support the heaviest conventional vehicle loads without distorting.