STRUCTURAL DESIGN Structures Gallery Space Movable Frame Design The objective is to fully utilise last remaining gantry crane of the IRT Powerhouse. The crane will be fully operational and will be the primary point for raising and lowering the new space frame roof to create a dynamic exhibition space. We are using a space frame with mild steel circular hollow section members, and galvanised steel cables (a).
The connections are prefabricated and it's only after that members are bolted in situ.
(c)
(a)
(d)
The frame is restrained laterally on rollers in bracket channels connected on to the existing columns, while secondary cables are connected to existing crane roller girders (h,i).
The structure is statically inderminate, however redundancy increases the safety of the frame. The suspension on cables removes any requirement for temporary cranes, which would be required if the frame rested upon columns. We have decided to use a space frame as they are lightweight, easy to assemble and offer a large number points to suspend services or equipment such as lighting from, which increases the flexibility of the space.
(h)
(i)
(e) Treating as an equivalent beam in section :
(f)
(g)
(b)
Threaded connections : The CHS members thread onto the nodes with bolts, which are then secured with dowels rather than the nuts used in a normal bolted connection (c,d,e,f,g). 31
Cable support locations
