Wednesday, April 19, 2017

HEC-RAS 2D Land Cover from AutoCAD

I had a bit of trouble getting a Land Cover map from AutoCAD to HEC-RAS today. I made a map, but HEC-RAS kept telling me the file "has 0 features". It turns out I needed to set the project projection to the projection exported from AutoCAD with the Land Cover map.

Sunday, April 16, 2017

How Roughness and Loss Coefficients are Applied to Reaches in HEC-RAS

It's really hard to find a clear explanation of how roughness and loss coefficients are applied to reaches in HEC-RAS.  I ran extensive scenario testing today and here are my results.

Sunday, March 5, 2017

Automated AutoCAD GIS export to Maricopa County DDMSW hydrology

I have finished the first version of the open source work-flow optimized application at AutoCAD Wiki.  It works like this:

Tilde conflict between AIA/NCS layer name specification and AutoCAD wildcards

National CAD Standard (AIA) layer name specification version 6 (2014) allows us to use only alphabetic and numeric characters and "~" (tilde) in layer names.  But the tilde has a wildcard meaning in AutoCAD.  What are we to do?

Saturday, February 18, 2017

AutoCAD Civil 3D in Windows 10 Qsave and Xref Load Performance Quest

I am on a quest to improve the performance of my AutoCAD Civil 3D 2016 in Windows 10.  I am tracking all my attempts in a Google Spreadsheet with records of what effect each has.  Trying to be a good scientist.  Feel free to check it out and comment.

Friday, February 17, 2017

How to verify my digital professional seal on an engineering plan

For the past decade my engineering plans have been digitally signed. This means that the official copy of all plans I seal is the digitally signed PDF file.

Thursday, February 16, 2017

AutoCAD Dimscale 0 - What's really happening

As of AutoCAD 2017, the AutoCAD help is wrong in its description of 0 values for dimscale.  Here's what's really going on from what I can tell.

Tuesday, February 14, 2017

How to map a drive letter to a local Windows folder

We freelancers are using Dropbox as a virtual network for our civil engineering and AutoCAD Civil 3D files. And it's really great (especially since I have a daily backup set up).  But some programs want us all to have the same absolute path to our files.  To do that, we have to each map our Dropbox folder to the same virtual drive letter.  Piece of cake!

Monday, October 24, 2016

Turn and Drop: A Counter-infiltration Tactic for Non-violent Direct Actions

Arab Spring was yet another example of the irresistible trend of non-violent populist movements toward violence.  Marginal violent actions by infiltrators or violent factions have explosive power to hijack and doom revolutionary movements.  The toolbox of rigorously trained non-violent revolutionaries is incomplete without effective counter-infiltration (counter-hijacking) tactics.  This post presents one: Turn and Drop

Tuesday, October 4, 2016

Minimum Wage and The Balance of Power -- Labor Market Musing

Minimum wage laws are a Band-Aid. They are harmful because they amount to price-fixing. They are necessary because the balance of power in the labor market disfavors laborers.

Since I am passionate against price-fixing and passionate against systemic imbalances of power, I am passionate about brainstorming labor market reforms that dissolve demands for minimum wage laws by shifting the balance of power toward laborers. So this is a brainstorming post about labor market reforms that may replace minimum wage laws.

Monday, September 19, 2016

Restaurant Huauchinango's Puebla Style Mexican Food

The owner of Restaurante Huauchinango's Mexican Food Puebla Style Mexican Food Restaurant asked me to get his Google Business listing fixed up with all the right information.  That's going a bit slow, so meanwhile I thought I would jot down the pertinent info here where I keep all good info.

Saturday, September 3, 2016

HEC-RAS 2D Area Stability

I did some testing on stability and accuracy for a HEC-RAS 2D only model.

Exporting a HEC-1 Hydrograph for HEC-RAS Unsteady Flow

We are going to export a HEC-1 hydrograph to a DSS file to use in HEC-RAS unsteady flow modeling.  This will be useful for us to do 2D flow modeling in HEC-RAS

Friday, September 2, 2016

HEC-RAS Reach Lengths and Civil 3D Export

When you export geometry from Civil 3D to HEC-RAS using ExportHECRAS, of course you wonder exactly what reach lengths Civil 3D is exporting, since your friction losses are proportional to those lengths,  Well.  Wonder no more.  As of Civil 3D 2016, the reach lengths are exported like this:

Sunday, August 28, 2016

Importing From HEC-RAS to Civil 3D using the IMPORTHECRAS command

When you export from HEC-RAS (File, Export GIS DATA) you must check the Water Surface Extents checkbox.

The "cross section" lines that come in are not really the cross sections.  They each represent a straight line from the left inundation limit to the right inundation limit.

Maybe it's time to write a LISP routine.