Assigning Minimum Pipe Slopes in Civil 3D Pipe Networks

Randy McCollum | Applications Expert

As a designer, you already know that the minimum allowable slope for a pipe is a function of three things:

1. The material of the pipe or internal lining in contact with the water being conveyed.
2. The pipe’s internal diameter.
3. The intended usage of the pipe.

The following is a demonstration of the way to assign minimum slopes for a pipe network to each pipe size/material combination automatically for a specific network type.

In this example, I will be creating a parts list for a sanitary gravity network using 12”, 18” and 24” diameter reinforced concrete pipes.  We first must make sure that our parts list has the appropriate pipe size and material combinations assigned to the list.  In Autodesk Civil 3D, within the Toolspace panel, select the Settings tab.  Find Pipe Network in the Toolspace window and expand Parts Lists.  Select the parts list you wish to edit, right-click and select Edit.

Once inside the Network Parts List window, select the Pipes tab.  Expand the parts list name and material type collection to see a list of the pipes assigned to this parts list.  By default, each pipe has one Rule defined called “Basic”.  It is with these rules that we can assign our individual minimum slopes.

Start with the 12-inch Concrete Pipe row, select the pipe symbol in the Rules column to open the rules creation dialog.  Because the Basic rule has some correct information, we can make a copy of this rule as our basis of our new rule.  Select the dropdown arrow to the right of the dialog button and chose Copy Current Selection.

From the Pipe Rule Set dialog, select the Information tab and give the new rule set a name.  Go to the Rules tab, expand Cover and Slope, and set the appropriate minimum slope value for this pipe.  Click OK to accept, then repeat the rule creation process for the remaining pipes in the Parts List.

Once all your rule sets have been created and assigned, you can create a pipe network based upon this parts list and be assured that you the rules will never make a pipe with less than minimum allowable slope again!