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#Construction simulator 2012 access violation how to#
#Construction simulator 2012 access violation download#

I put in a baseflow (minimum flow) of 5% of this, which is 30 cfs. Peak discharge of your inflow hydrograph is around 600 cfs. However, the first time step flow is very low at 0.14 cfs. In the original model, the initial flow is left blank (which is actually okay because RAS will use the first timestep flow if left blank).

In the unsteady flow editor, the initial flow and the first time step flow should always be equal.

That way the errors that do originate from your downstream boundary assumption will have diminished to negligible levels before impacting your area of interest. Either way, this underscores the importance of moving your downstream boundary far away from your area of interest in your study reach. In absence of downstream conditions, the 0.001 slope for normal depth provides a reasonable solution. The proper way to handle this would be to find out what is downstream of your model and select a boundary condition that best represents those conditions. This creates an overestimation of the water depth at the next upstream cross section, which in turns creates some instability over the next several timesteps. Notice in the following profile plot of the downstream end of the reach how the water surface at the boundary cross section is below critical depth (the red dot). Not sure what is downstream of the first cross section, but 0.01 is awfully steep and was setting up a very low depth at the downstream boundary (which was causing instabilities).

I changed the downstream boundary normal depth slope from 0.01 to 0.001.

Close enough to 10 seconds, so we’ll stick with that. That suggests a time step of 8.3 seconds. In this case, the cross section spacing is 50 ft, and I was able to pull some velocities (prior to the model crashing) at about 6 ft/s.

Also, setting the cross section spacing/timestep ratio equal to a representative stream velocity will get you close. There are some methods for approximating good timesteps, notably the Courant Condition and Fread’s equation. The selection of 10 seconds was based on “gut” feel and lots of experience doing dam breach models. This model was initially set with a computation interval of 10 minutes which is high even for the largest and “slowest” of dam breach models. Dam Breach models typically have time steps on the order of a minute or less.I interpolated to 50 ft for the entire reach. Profile Plot Samuels equation suggests anywhere from 15 ft to 50 ft spacing (depending on what bed slope you use). A visual check alone of the geometry schematic and profile plot should encourage you to investigate a finer cross section spacing. The links following some of these items will take you to more information about that particular technique.ġ.

#Construction simulator 2012 access violation download#

Feel free to download the “Unstable” and “Stable” models and try these techniques on your own. The following lists out the courses of action taken to stabilize the model.

RawleyResStable.prj is the fully stabilized version of the model with no numerical errors.

Although the model ran to completion without crashing, it had unacceptably high errors. RawleyResUnstable.prj is an unsteady flow dam breach HEC-RAS project recently sent to me for help. I’ve uploaded two HEC-RAS projects to the following Google Drive Site:

#Construction simulator 2012 access violation how to#

Either way, approaching an unsteady HEC-RAS model (especially a dynamic one) as a beginner with little experience and understanding of how to stabilize it can cause significant delays in your project and worse, completely blow up your budget. The dreaded “Red Bar”! Sometimes you can get your simulation to complete without crashing, but the listed numerical errors are so high that you can’t with good conscience submit that as your final simulation. Then you’ve painstakingly spent hours…possibly days entered all of that data only to find that once you press the “Compute” button, the model crashes. You know, you’ve gone to great lengths collecting the best survey/topo data and solid hydrology. One of the most frustrating aspects of unsteady HEC-RAS modeling can be the model stabilization process.