Design Section Staging

This command takes a design cross section and splits it into two stages for cases when the design surface will be built in stages. There are two staging methods.

The Offset method splits the design section at a specified offset with the left side as one stage and the right side as the other stage. This method applies to the situation of designing a partly completed road or regrade. For example, if a four lane road will built two lanes at a time, then the offset method can be used to split the design section with two lanes on the left side of the offset and the other two lanes on the right side. Using an existing and a final grade section file, the program will create four new sections files for the finished existing sections, finished final sections, remaining existing sections, and remaining final sections. The source existing and final section files should have matching stations. There is an option to process a range of the possible stations from the section files. The complete part of the road can be either on the left or right side. The pivot point is a cross section offset where the completed part ends. From this point, the final grade will connect to the existing grade by a line at the specified slope.

The Description method uses a specified description from the existing ground section file plus an offset from this description. Then the existing section is overlaid onto the design section for the offset zone around this description. This method applies when a portion of the existing ground stays intact when the first stage of design is built and then this remaining portion of the design is done as the second stage. For example, this applies to improving railroads where the existing track is left undisturbed while the work for the new bed is prepared. In this case, the existing section file should have a description for the offset position of the existing track centerline. Then you specify the buffer offset around this centerline. From the resulting left and right offsets, the program ties the existing section into the design at a specified slope.

Prompts

For Offset Method:
Select Existing Sections File Choose the cross sections file.
Select Final Sections File Choose the cross sections file.
Enter slope as percent grade or slope ratio [Percent/<Ratio>]? press Enter
Enter the fill slope ratio <2.0>: press Enter
Enter the cut slope ratio <2.0>: press Enter
Stage by side from offset or overlay existing at description [<Offset>/Desc]? press Enter
Place road on left or right [<Left>/Right]? press Enter
Range of stations: 50.0 to 100.0
Enter the starting station to process <50.0>: press Enter
Enter the ending station to process <100.0>: press Enter
Apply same pivot offset to all stations [Yes/<No>]? Y
Enter the pivot offset (enter left offsets as negative) <0.0>: 5.0
SCT File dialogs Enter new .SCT file names for 1) existing road .SCT file, 2) final road .SCT file, 3) remaining existing .SCT file and 4) remaining final .SCT file.

Here is an example of the Offset method showing the original existing and design sections and then the four new sections files for the finished existing sections, finished final sections, remaining existing sections, and remaining final sections that the routine creates.

For Description Method:
Enter slopes as percent grade or slope ratio [Percent/<Ratio>]? press Enter
Enter the fill slope ratio <2.0>: press Enter
Enter the cut slope ratio <2.0>: press Enter
Stage by side from offset or overlay existing at description [<Offset>/Desc]? D for description
Existing section target description: CL
Range of stations: 100.00 to 100.00
Enter the starting station to process <100.00>: press Enter
Enter the ending station to process <100.00>: press Enter
Enter the buffer offset <0.0>: 4

Here is an example of the before and after for the Description method.

Pulldown Menu Location: Sections
Keyboard Command: sctstage
Prerequisite: Existing and final grade section files (.SCT)