Thrust Forces / Scissor Trusses 2

[sigma1]

Is it safe to assume that there would be no thrust forces (or the forces would be released) on individual square concrete footings with base pedestals supporting "Scissor Trusses" with pin-pin connections? It is an open roof structure with wind loads on all directions.

 

[flamby]

Difficult to see what you mean. Impossible to think of anything, truss or otherwise, not imposing thrust on slight change of temperature (leave alone the loads) with pin-pin connections.

 

[Grizzman]

The thrust will be resisted by the footings and the pedestal. the pedestal must be designed to resist "flagpole" bending as well as exial loads. Don't forget overturning of the footing and increased soil bearing pressure.
It is inaccurate to say there is no thrust, but provided the footing and pedestal are correctly designed to resist said forces, it would be accurate to say they were relieved.

 

[SperlingPE]

If pin-roller support the thrust forces are relieved.
If pin-pin the thrust forces are transferred to the pedestal, to the footing, to the soil. The soil ultimately resists the thrust forces.