Steep Fill Section Realignment
Updated November 30, 2017
This article applies to:
- RoadEng Civil
- RoadEng Forestry
From a customer: "One type of road we see that needs attention is the older side-cast constructed road with the overly steep shoulder fill. These roads often have a tension crack showing up on the outside wheel track. We typically want to retrieve this side-cast material, haul it to a disposal site and move the road alignment into the hill or just live with a narrow road."
Here we will stabilize the oversteepened fill, find out how much volume must be removed and what the finished cross sections will look like.
1. Survey the road keeping track of the location of the toe of fill. If you are doing a centerline with cross sections style of survey, then put the centerline at the toe of fill. If you are doing a radial or topographic style of survey then be sure to survey and label points on the toe of fill.
2. Create a P-Line in the Survey/Map module with your survey. A centerline with cross sections survey can be directly typed into the Survey/Map module.
NOTE: A topographic survey must be imported into the Terrain module and triangulated (Edit-Calculate Terrain Model), Road edges, top of cut and toe of fill features should be breaklines to make the best model possible. Breakline (and other) features can be imported directly from the survey (ASCII or DXF) or they can be created later using the Edit-Digitize/Draw New Feature function. The View-Plan Options- Snap to Point option makes it easy to connect surveyed points into a feature.
3. After the model is created, the toe of fill feature must be exported to a Softree-Traverse Document with side shots (File-Export Feature(s)); use the options button to select side shot extension.
4. Go to the Location Module and create a new design with the new P-Line.
5. Edit the default Template to have a very small road width and no ditches. Leave the final slopes at Auto.
6. Set the cut slope for the surveyed ground type to the stabilized pull back slope. Set the fill slope to a large value. (The ground type for a file exported from Terrain will be OB).
The design is complete. The default location of your "road" is on the P-Line (which is the toe of fill. The cut from there up to the road surface is the stabilized pull back slope; there will be no fill because the fill slope is large. View your cross sections and look at the mass haul for volumes