How-to guide
A car park has to drain: it falls towards gullies at 1 in 60 to 1 in 80 or so, and anything flatter ponds. Its levels are finished surface levels; the earthworks are to formation, under the pavement construction. This guide sets the fall and build-up of a service yard in Metre2 Earthworks Pro, adds a gully and reads the result.
Draw a Car park (Design tab) or select one. The sample's service yard sits 1.2 m below the warehouse floor, behind a dock wall.
Type the fall in X or Y as 1 in 60 (or 1.67%). The checks warn when a car park is flatter than 1 in 80 and may pond.
The pavement build-up (surfacing, binder, base, sub-base) takes the finished level down to formation: 500 mm here.
Add a gully, click where it goes and type its level. The surface falls to each gully from the corners, so you can model a yard that falls to several low points. Corners can each have their own level too.
The yard now needs 6,141 m³ of cut to formation. The heat map shows where.
Commonly 1 in 60 to 1 in 80 (about 1.25-1.67%) to the gullies or channels; flatter than that it may pond. Check the drainage designer's levels.
To formation: the finished surface less the pavement build-up. That's the level the groundworker digs to.
Car parks are in Earthworks Pro (£19.99 a month or £179 a year, with a 7-day free trial).
No. Earthworks runs in your browser: survey files, LIDAR tiles and PDF drawings are read on your computer and the project is kept in your browser until you save it as a file.
