BIM on the Rocks

Culvert Analysis in SSA

Autodesk Storm and Sanitary Analysis offers users the ability to perform runoff calculations and hydraulic routing calculations in a single package.  This combines the best of both worlds.

SSA’s hydraulic calculations are founded in the EPA SWMM calculations which performs the one-dimensional Saint Venant flow equations. The Saint Venant equations consist of the continuity and momentum equations for conduits and a volume continuity equation at nodes.  What this means is culvert entrance and exit losses are computed not on the nodes themselves, but rather on the pipe ends.

Let’s dissect how this happens.

1. Open the SSA Sample Culvert file.  (C:\Program Files (x86)\Autodesk\SSA 2013\Samples\Culvert\Culvert.spf)
2. Double Click on the Culvert Pipe shown in the image above.  The Shape definition is described as a “Culvert”.  In many cases, if you exported your Civil 3D Pipe network, the imported pipe may be just a “Pipe”.  
3. By selecting Culvert, the available properties of the conveyance link changes.
4. The HDS-5 Culvert type and Culvert Entrance properties become available.  Be sure to visit the Flow Properties section immediately below and properly set the Entrance and Entrance Losses.

The model is set for analysis. 

Here is one tip when exporting your Civil 3D pipe network.  If the Part Matching Default Settings on Export, set the upstream structure to Headwall, SSA imports that structure as a Junction, and sets the following downstream pipe to a Culvert.

One could conceivably use the Part Matching Customization Settings in SSA to match set a specific part family to a culvert, but that is a topic for another day.

Claiming Water Wednesday

This is a guest post by Matthew Anderson, PE CFM.  Dana has graciously allowed me to put together a series of posts for her BIM on the Rocks blog! Thanks Dana!

My family typically performs menu select with a bit of a rhyming game based on the day of the week.  For example, yesterday was Taco Tuesday. The kids enjoy trying to rhyme what we have to eat based on the day of the week. For this series of posts, I am claiming Wednesday for the similar reason; Wednesday will be henceforth known as Water Wednesday!

I am open to suggestions, or answering questions when it comes to the content of these posts – the only caveat being it needs to highlight the water resources tools available in AutoCAD Civil 3D or Map 3D. 

A few years ago when Autodesk University first introduced AU Virtual, I presented a class using the Hydraflow Express Extension.  A key component of that class discussed the use of catchment area to define the watershed area to a roadway cross-culvert.  Those values were then transferred to Hydraflow Express for a simple runoff calculation and culvert design. There were a lot of viewers, and a good response to the class.  One of the key benefits I highlighted was the Express Extension’s simplicity. 

In AutoCAD Civil 3D 2013, the Express Extension expands the ability of the user to solve more of the FHWA HDS-5 Culvert types. What was just an “Inlet Edge” input parameter in earlier versions, is now Culvert Type, and Culvert Entrance.  This brings Hydraflow Express closer to the requirements and options outlined in Federal Highway Administration HDS-5 document from 2005.  (FHWA HDS-5, 2005) .

This expands the available design solution options for roadway culverts in using Hydraflow Express.

 

 

 

 

 

 

 

 

Next week, we we will review culvert routing in Autodesk Storm and Sanitary Analysis.

P.S. I know that FHWA recently released a new version of HDS-5 in February 2012.

Using Civil 3D Stage Storage information in SSA

I’m in Novi, Michigan this week working with the Vault team and learning more about Vault Collaboration AEC. I noticed Matt tweet about using the results of a Civil 3D Stage Storage analysis in Autodesk Storm and Sanitary Analysis, so I asked him to write it up.

Here is Matt:

I despise the unnecessary duplication and manual process of transcribing data for analysis. The case in point that I want to discuss is the construction of Stage-Storage Curves. Autodesk Storm and Sanitary Sewer has the ability to load a text file to construct the stage storage curve. AutoCAD Civil 3D’s Stage Storage tool has the ability to export the analysis to a text file. Let us see how these two come together in 2012.

The Stage-Storage tool moved from the Toolbox into the Ribbon -> Analyze Tab, below the fold at the bottom of the tab.

In launching the Stage-Storage Tool, you can query or build your Stage-Storage table from the surface, or a family of polylines extracted from the surface. After defining the basin, the Stage-Storage Volume Table will contain the Elevation-Area and Volume information, or Stage-Storage tabular data. Below the Volume table is a Save Table button that will allow you to export the information to a text file with the Stage Storage File *.AeccSST file extension.

This file extension can be loaded into a Storage Node within Autodesk Storm and Sanitary Analysis 2012 so that this pond,

is loaded into SSA as this Storage Curve,

Happy Modeling!

New for Water in AutoCAD Civil 3D 2012: Catchments

Since I am still technically on maternity leave, Matt Anderson has written up information on some water goodies for 2012. Thanks, Matt!

While Dana is resting comfortably tending to Project Galileo, I offered to pen a few posts to keep the blog off the rocks. I hope it keeps me from playing Words with Friends…

A little over a week ago, the Autodesk 2012 product line announcements went public, and the new and improved features of AutoCAD Civil 3D 2012 went live, sending Twitter and a few blogs or here or here on a frenzy of discussion, comments, and teaser posts of new features within the future Civil 3D 2012.

Catchments

The Catchment command introduced a couple of releases ago, graduates to become a full Civil 3D object. The Catchment is a calculation of the surface’s drainage patterns to a point or location on a surface or discharge point. The object searches within its boundary to locate the hydraulically most remote point and the flow path used to travel from the most remote point to the discharge point.

In English terms, the catchment calculates the time of concentration value.

As you might notices in the attached dialog box, the groups of catchment can band together to organize either different stages of development or different pipe networks. With that said, the catchment’s discharge point could be attached to a structure.

This connection allows Civil 3d to Export the catchment area, the runoff coefficient and the raw time of concentration data out to Hydraflow Storm Sewer Extension or off to Autodesk Storm and Sanitary Sewer to save you a step of manually transferring that information for analysis.

Until next time…

Civil 3D with Storm and Sanitary Analysis Webcast Thursday 9-9-2010

I spent my summer digging through piles of work, harassing James everywhere from Park City to Waltham, and helping Panorama with her first State Fair entries. One of the contests was a LEED certified gingerbread dwelling.

We’re back to school now, so I suppose I need to get into the habit of slapping something up here once in awhile instead of getting my social media fix on twitter.

Tomorrow, Thursday, September 9, 2010 at 1PM EDT, I will be leading a webcast on using Autodesk Storm and Sanitary Analysis with Civil 3D.

Water Infrastructure Design Using AutoCAD Civil 3D 2011

Thursday, September 9, 2010

In this session, we'll take the recommendations from the drainage planning study presentation to design a stormwater management system for a neighborhood. We'll build upon data from the drainage planning study and show how to do a surface analysis and determine drainage catchments in Civil 3D, design a drainage system in Civil 3D, share pipe network and catchment information, and more! > Register Now

 

If you are interested, I did one a few weeks ago on using Map 3D and Autodesk Storm and Sanitary Analysis.

Water Infrastructure Planning Using AutoCAD Map 3D 2011

Thursday, August 19, 2010

In this session, we'll use Map 3D 2011 along with Autodesk Storm and Sanitary Analysis Stand-Alone to do regional planning for a citywide stormwater drainage system. See how you can aggregate data from multiple sources including SHP and raster imagery using Map 3D 2011, share data with Storm and Sanitary Analysis to build analysis model, run simulations and analysis in Storm and Sanitary Analysis, and more! > Watch Now

 

Also reference:

Technical orientations to Autodesk Storm and Sanitary Analysis in a youtube playlist

Autodesk Storm and Sanitary Analysis Users Guide (pdf - 37237Kb)

Autodesk Stormwater Discussion Group

Excel Reports from Storm and Sanitary Analysis

Contributing Subbasins and Links in Storm and Sanitary Analysis

Civil 3D Pipe Networks to Autodesk Storm and Sanitary Analysis

Using Hydraflow Express for Channel Calculations

I was working through a predevelopment time of concentration yesterday using Civil 3D and Autodesk SSA, and I needed a cross sectional area and wetted perimeter for a natural channel.

In Civil 3D, I had my TC path drawn, and using the terrain model, I could see where I entered into channel flow. I used some quick profiles across the channel, some surface analysis and slope arrows to help me get my bearings. 

Then, I made a short alignment across a representative section of the channel. You could make as many as you’d like.

By making an alignment, I could make a profile and profile view as well as labels. I traced the existing ground profile with a layout profile to get more crisp tangent lines, then used profile labels for 1:Z slopes. I used Seth’s trick of using line labels as dimensions to give me some of the other pieces I needed to calc the CSA and WP.

Then, I launched Hydraflow Express from the Analyze tab in Civil 3D.

It was easy to enter the bits I needed for the calculation thanks to my profile view labeling. I could have added a few more labels- such as invert elevation, etc. if I wanted to get more information from the calculator.

As you experiment with Autodesk SSA, don’t forget about the tools in Hydraflow Express. There is no wrong way to use the tools in your toolbox- find the combination that gets you what you need for your design.

SCS Type II vs Huff Distribution and Autodesk Storm and Sanitary Analysis

I was working on something using some data from the Chicago area. Since all of my stormwater experience is limited to a few Mid-Atlantic states, I am glad that Matt Anderson could help me out yesterday. He explained the difference between SCS Type II distributions and Huff distributions. He was kind enough to record this short video for me in Autodesk Storm and Sanitary Analysis. I just love listening to his casual, friendly Chicago accent it makes me want to grab my overcoat and head out for some deep dish pizza somewhere with a lake view.

There are a ton of distributions available in the SSA rainfall designer- SCS, various counties, Florida DOT, Seattle… many more.

You can learn more details about the rainfall designer in the Autodesk Storm and Sanitary Analysis Users Guide (pdf - 37237Kb).

Have questions? Visit the Autodesk Stormwater Discussion Group.

For a detailed technical orientation, see the Overview of Autodesk Storm and Sanitary Analysis videos on youtube.

Excel Reports from Storm and Sanitary Analysis

We’ve all had to make stormwater reports that include endless summaries and tables. One way to get what you need is to use Excel. SSA has a tool that exports your model elements and information to excel.

Output > Excel Table Reports

The whole model gets pushed to an Excel workbook- with each element getting its own worksheet.

Here is a closer look at the subbasin output. A nice way to get a summary of weighted CN, Time of Concentration, etc.

Autodesk Storm and Sanitary Analysis is available for North American subscription customers of Civil 3D and Map 3D. You can download SSA at www.autodesk.com/subscription, and learn more about SSA, including demonstration videos, here.

You might also want to read: Moving Civil 3D Pipe Networks to Autodesk Storm and Sanitary Analysis.

Contributing Subbasins and Links in Storm and Sanitary Analysis

I learned how to design drainage networks using a spreadsheet. It took some time, and creative use of color coding in Excel, but I somehow became capable of understanding which pipes and areas were cumulatively contributing to each other, but it was disconnected to a physical representation of my site which was in AutoCAD or Land Desktop.

I was working with a model in Storm and Sanitary Analysis (former StormNET) and I noticed something interesting. If you select a junction and right-click, you can highlight all of the contributing subbasins.

This would have been extremely helpful for answering questions like- “Why is this pipe so big?” or “Where can I make changes to my impervious area to really make a difference in runoff?”

Another choice on that right-click menu is contributing links. It highlights all of the pipes that contribute to the flow at that node.

It really would have been nice to have a tool like this when working on things like drainage plans for Neighborhood Design Reports that I wrote about here..

Autodesk Storm and Sanitary Analysis is available for North American subscription customers of Civil 3D and Map 3D. You can download SSA at www.autodesk.com/subscription, and learn more about SSA, including demonstration videos, here.

You might also want to read: Moving Civil 3D Pipe Networks to Autodesk Storm and Sanitary Analysis.

Webcast on Storm and Sanitary Analysis (Former StormNET) in Action: June 15, 2010

I had the chance to talk with Tim Olson from Bolton and Menk in Mankato, Minnesota month or so ago about how they used StormNET (now Autodesk Storm and Sanitary Analysis) to help with a stormwater plan for the City of Ramsey, Minnesota. I wrote about how Autodesk Storm and Sanitary Analysis can help with citywide drainage studies here.

Chris Maeder, PE, MS (formerly of BOSS International) will be hosting a CE News webcast on June 15, 2010 featuring Tim speaking about the City of Ramsey project.

Register for the CE News Automation Innovations in Stormwater Modeling webcast here.

From the CE News description:

Automation innovations in Autodesk’s recently released water resource engineering software allows civil engineers to more efficiently and economically complete stormwater analysis and design projects. This presentation showcases a stormwater project in which a major engineering firm was able to complete a 30 square mile metropolitan stormwater management plan in half of the time that it would normally have taken. This project incorporated wetlands, ponds, streams, and stormwater pipe and ditch networks, and the stormwater management plan had to accommodate 10 and 100-year storms and comply with city, county, state and federal EPA standards. This project was completed within 5 weeks, using a variety of CAD and GIS source data to construct the model. The final model was turned over to the city stormwater utility department to use on future projects, particularly in evaluating the impact of new developments on existing structures.