The Road Offset Calculator Spreadsheet.
This is a very handy spreadsheet for Site Engineers who are setting out roads and need to calculate the offset co-ordinates and levels of many points along a road. With this spreadsheet you will have at your hands all the offset co-ordinates and levels required along the road.
For this spreadsheet to calculate the offsets and levels, you need to have co-ordinates (Eastings, Northings and Elevation) for the Left Hand Channel, the Centerline and the Right Hand Channel at each Chainage (cross-section) of the road that you need to calculate.
This Spreadsheet will allow Chainages from 0 to 1000 in 10m increments.
Once you have entered your co-ordinates for the Left Hand Channel, the Centerline and the Right Hand Channel, you then need to decide on the offset that you require. Standard offsets usually used in construction is 1m offset and 1m above Finished Road Level.
The Road Offset Calculator Spreadsheet also provides information on the road cross-section. It provides the distance from the Centerline of the road to both the Left Hand and Right Hand Channels, these distances are not always equal but the spreadsheet will take this into consideration. It also shows the amount of fall from the Centerline to the two channels, remember that one side could be negative in the case of a superelevated road. Also calculated is fall across the road in mm per m, this is very handy for checking or offsetting levels further.
The results page of the road offset calculator spreadsheet provides the eastings and northings of the offset profile along with two levels, one for Left Hand Carriageway and one for the Right Hand Carriageway. You can copy all off this data and put it into a csv format to load up into many different total station or gps instruments.