Infratech Civil

Product:  Autodesk SSA  |   Subject: Storm and Sanitary Analysis

In this exercise, we will learn about SSA Analysis Options. 

Introduction to SSA Analysis Options

Next, we need to enter the Analysis Options. This is where we will specify the options for computing the model and hydrology methods we have set up. 

1. In the data tree, double-click on Analysis Options.

2. In the Analysis options window, the General tab is where we define the simulation time steps, dates, hydrodynamic routing parameters, and any external interface files to be used. For now, we will only need to worry about the simulation time. For the Rational Method, we typically use a 1-hour simulation, since most of the action happens in the first 15 minutes for small sites like this one. This is because, if we look at IDFs curves, the higher intensities are at the start of the storm. Extended detention models, such a TR-55 or SWMM model, for example, require at least a 24-hour analysis. So, let’s set the duration to 60 minutes. The dates don’t really matter, as long as there is a one-hour difference between the Start Analysis on and End analysis on dates. So just add one hour to the end.

3. Next, click on the Storm Selection tab. It allows us to define the storm or storms to be analyzed. At this stage, we haven’t defined any storm yet. So, we don’t have much work to do on this tab. We will revisit it once we have defined our storm events. Click OK to close the Analysis Options tab.