Analyze Gravity Systems in Civil 3D (5:01 min)

The Storm Drain design is one of the most important parts of a project. Engineers and Designers ask themselves all the time: “Where will we drain the site to? Where will the detention pond be?” or, “How large do our storm drain pipes need to be?” There are so many variables to consider and analysis tools to use, which can often leave us wondering what to do next. Let’s see how Civil 3D can help us streamline this process.

Analyze Gravity Systems in Civil 3D:

This tool is now native to Civil 3D, further minimizing the amount of exporting needed from Civil 3D. We can analyze a piece of a pipe network directly in Civil 3D, and even apply those analysis results to the entire pipe network. There are 3 options for Analysis:

1. Resize Pipes and Reset Inverts
2. Compute Energy and Hydraulic Grade Lines
3. Inlet Analysis

Using the Gravity Systems in Civil 3D:

1. We first want to specify catchment areas by opening up our Active Drawing View, selecting catchments, creating a catchments group, and we have the choice of creating one by object, or surface.

2. Once the watersheds are in, we can identify which inlet box to assign them to.

3. We then need to select the “Analyze” tab in our ribbon and select the “Analyze Gravity Network” and select a pipe network.

4. Here our 3 analysis options show up allowing us to choose what type we would like done on our pipe network. An outfall can be selected from the drawing anywhere we choose, tailwater conditions can be set from a variety of options, and rainfall and annual exceedance data can also be added in this same window.

5. Before running the analysis, verify/change any network details and settings that need adjusting and select “Analyze”.