In this video we show how to use the TBC Corridor Modeling Tools along with RPS Cloud Services to solve a complex modeling problem.
In this scenario the end user requested that we show how to build a road design over existing terrain that is undulating and sloping both left to right and right to left along the alignment, while maintaining a 4.0’ height of the road bed above the existing terrain surface.
While the Conditional instructions of the road model could be used to solve this problem, the conditions would require many conditional statements and would be hard and extremely time consuming to create and get right.
Instead we used the RPS Cloud Services command to solve the problem by writing a script and using Ask rocky to solve the issue for us.
To create the scenario requested, you have to sample a number of locations across the road section at all locations along the road, to determine what the existing terrain is doing. In this example we used 5 sample locations i.e. at Centerline, 6’ and 12’ right and left of centerline.
We then used standard TBC instructions to determine the Ground + 4.0’ elevation lines and made a surface layer in the corridor that connected the 5 lines together longitudinally into a surface. That surface generates linestrings along the path of the road, that are subdivided into chords of a length defined by the template.
We then used the RPS Point Creator to create 3D points at all of the node locations along the lines, and numbered those so that all the points at the same station have the same Point ID.
We then used those points with Ask Rocky to analyze the 5 points at each station, find the highest of the 5 and return a point at centerline that has the high point elevation. We then create a line between those points to determine the high point line along the centerline of the road. The high point in each section is the point that defines the height of CL to ensure tat all f the road bed is at least 4’ above existing terrain.
At this point we would normally design the true road alignment that follows those high point locations, and insert vertical curves as needed to smooth out the vertical profile and then use that to build finished grade surface. I skipped that step in this video.
We then built the corridor using the vertical profile we created to create a finished grade surface model - to show that the process works. In this case we computed at 10’ intervals along the alignment, bear in mind, the 4’ will be correct at every 10’ station only, in between it will likely be close but it will not be perfect - to get more “perfection” you would need to compute at a tighter interval etc.
This is a great procedure that shows the power of RPS Cloud Services to solve this specific problem and we can likely further automate this from here
Here is the Ask Rocky Script to use if you need it
In the attached points, each point has a Point ID (Point), a Northing, Easting and Elevation Value as well as a Description. Points with the same Point ID should be treated as a group of points that lie on a straight line. The point in the middle position of the group is at the centerline position of a road. Find the point in each group that has the highest elevation, and return a single point for each group that has the same Point ID as the source data points, the same Northing and Easting of the Centerline point and the highest elevation value.
Generate the output as a csv file in Point, Northing, Easting, Elevation, Description format. For the Code value use CLHP.