A wobbly park bench on uneven pavement is super common, and you can usually fix it without replacing the whole bench. First, find the leg that is not touching. Rock the bench gently or have someone sit on it while you slide a flat pry bar, putty knife, or shim under each leg. The leg with the biggest gap is your problem.
Then pick the method that fits your bench:
1. Shims: Tap plastic or rubber shims under the low leg until it sits firm. Use one solid shim or a glued stack, not a loose pile. Trim the excess with a utility knife and secure it with outdoor construction adhesive so it doesn't slip.
2. Adjustable feet: If the bench legs are hollow metal or wood, install adjustable leveling feet. Drill a hole, insert the threaded foot, and turn it until the bench stops rocking. This is the cleanest long-term fix.
3. Paver or pad: For a larger gap, set the leg on a concrete paver, steel plate, or pressure-treated wood pad. Use construction adhesive or a concrete anchor to keep it in place.
4. Anchor the bench: If the pavement is solid but sloped, bolt the bench down with concrete anchors. Mark the holes, drill, and use wedge anchors or sleeve anchors. If the slope is severe, pour small leveling pads with quick-set concrete under each leg first.
Before you start, check the bottom of the leg for rot or rust. If the leg is badly damaged, repair or replace it before leveling. Also, if it's a public park bench, check with the parks department before making permanent changes.
After leveling, tighten all bolts and give it a hard sit test. You want the bench to feel solid with no rocking in any direction.