WallAlso riser. The vertical section between the bench and the cone of a manhole. or rampart, breast high. Also, the wall on top of an abutment extending from the bridge seat to the underside of the bridge floor and designed to hold the backfill.
WallAlso riser. The vertical section between the bench and the cone of a manhole. or rampart, breast high. Also, the wall on top of an abutment extending from the bridge seat to the underside of the bridge floor and designed to hold the backfill.