SewerGEMS: Automated Design Philosophy

Question

Hi, 
 
 I just need to understand how the automated design in sewergems operates? 
 Some questions: 
 
 When I have an existing network and want to join a new network to that I would only "tick" the "design conduit" for the new network in the flextable up until where it joins the existing network. Does sewergems now use this existing connection point as a constraint i.e. is it designing the new network from downstream to upstream or does it always works it way from upstream to downstream? 
 I understand that not all design criteria can be met in every situation for every pipe i.e. Min/max velocity, slope and cover. How does sewergems prioritize these? Does it use first look at the velocity up until where it violates the slope or until it violates the cover constraints? 
 
 If I know this better it will help me to approach the auto design better. 
 Another functionality or design criteria that could help a lot is have a min/max slope per diameter range. I would allow flatter slopes for larger downstream slopes but wont allow the flat slopes for smaller upstream slopes which leaves me to choose either a flat or steep slope. 
 Regards 
 Rossouw

Scott Kampa · Answer

Hello Rossouw, 
 
The automated design actually will solve both upstream and downstream. The following link has details: communities.bentley.com/.../19324.does-the-design-tool-in-sewercad-or-stormcad-design-my-network-from-upstream-to-downstream-or-vice-versa 
 
It will use the connection point, though if that connection point can be designed, it may change during the automated design process. 
 
For the design criteria, the following link has information on the design priorities: communities.bentley.com/.../18162.what-is-the-order-of-the-design-priorities-used-in-stormcad-gvf-rational-solver-and-sewercad-gvf-convex-solver . 
 
For a flat slope design case, there is an accommodation for that in the program already. If you set "Include Conduit Flow Travel Time in Design" to True in the calculation options, the program will be able to better account for shallow slopes. The following link has details on this: communities.bentley.com/.../10402.why-is-stormcad-over-designing-the-conduits-during-a-design-run-on-a-system-with-very-shallow-slopes 
 
Regards, 
Scott