Roof Wind Girder

41 cylingas preferred method jacking up for tanks.

Roof wind girder.

This paper considers the structural consequences of such simplifications including the substitution of a supporting structure of the roof or a wind girder by an equivalent thickness or by a fictitious boundary condition. Design of wind girders transverse wind girder in general the form of a transverse wind girder is as follows. It can be concluded that due to the higher internal pressure coefficient all the cities see an increase. A case study in the city of north las vegas demonstrates the comparison of wind uplift pressure for roof elements including joists and joist girders.

Wind girder roof in place as the top shell is erected first gap between the tank bottom and shell 350mm allows wind to flow through the gap reducing effects of the wind load on shell. Design standard can3 s1367 8 provides shear and tensile capacities for arc spot weld design. Thermal loads due to an adjacent fire uniform external pressure and wind pressure. Three load cases are investigated.

If the fixed roof is a cone roof no top wind girder is needed see above. 5 which in turn provide wind uplift resistance to the roof deck. Figure 6 shows the roof girder wind uplift pressure ratio between asce 7 16 partially enclosed building and 7 10 enclosed building. The wind girder is arranged as an x truss parallel to the roof plane the chords of the wind girder are the upper chords of two adjacent vertical trusses.

By definition internal floating roof tanks have a fixed roof. This means that the axial forces in these members due to loading on the vertical truss and those due to loads on the wind girder loading must be added together for an. The wind girder is arranged as a warren or pratt truss parallel to the roof plane the chords of the wind girder are the upper chords of two adjacent vertical trusses. If the fixed roof does not add stiffness to the top of the tank ie an aluminum dome roof see g 1 3 1 then treat the tank as an open top tank and evaluate for a top wind girder.

Open top or external floating roof tank do not have the benefit of this shell rigidity and therefore a circumferential wind girder is provided at or near the top of the shell to give it necessary.