FW: A mistake in Midas


When use the wizard to generate a curved bridge with parallel substructures (i.e. Girder Layout = Same Spacing), the wizard generated a wrong layout as shown below when curve is a convex curve. It works correctly for a concave curve. Can you please have a technical person to verify this and correct this in software if this mistake is confirmed?

Another question is when we will get the new version with design function to latest version of Canadian Bridge Design Code (supposed to be released at the end of February).



I understand that you are having trouble with 'Convex' option in the wizard.
However, I would like to know more specific details such as which points of the model from the wizard with 'Convex' type has a problem and what do you expect the model should be from the wizard.
Please tell us the problem in more detail and we will give you a response as soon as possible.


With the selection "Same Spacing" for girder alignment, all centre lines of substructures should be parallel as explained in screen guide of Midas. I verified that this was true for a concave curve bridge alignment but not for a convex curve alignment. The attached screen shot of frame layout I sent with my first email shows that three substructures are not parallel (supposed to be).


‘Same Spacing’ option as ‘Girder Alignment’ in Prestressed Composite Bridge Wizard is not to model each support line as parallel exactly.
What the program does is to make both length of span and spacing of girders same. So, if you reduce the value of radius, support line will seem to be parallel.

FYI, Program models with the wizard from ‘Reference Support’ to rest of parts maintaining the length of both girders and spacing.
The coordinate of the girder which is modeled at a location offset from a centerline of the bridge can be modified in ‘Section’ tab, you can view ‘ Girder Offset’.

‘Concave’ type works same with ‘Convex’ but only difference is the location of center of radius.

It is not possible to modify the wizard as long as the modeling condition of the wizard is as mentioned above.

Thanks & Regards,
Creation date: 10/24/2017 8:09 PM ()      Updated: 10/25/2017 6:01 AM ()