Articulated Bellows

Significant challenges were encountered in the design of this 100m tall Ø600mm pipe riser, with the initial 1000kN pipe anchor loads (gravity + bellows thrust) exceeding the limits that could be supported by the existing concrete building core.

A detailed analysis of pipe thermal effects, construction sequencing and design building movements enabled a reduction in the bellows displacement demands, while the constraints on anchor loads led to the exploration of ways to accommodate movements without generating thrust loads.

Articulated bellows were found to be a viable solution with multiple benefits.

The bellows were able to be repositioned out of the vertical riser shaft and into the upper plantroom, reducing construction safety risks and simplifying construction and future inspections and maintenance.

Secondly, the large axial thrust loads were eliminated, minimising the scale and number of the pipe anchors and lateral guides, and enabling the building-core load limits to be achieved.

Other significant complexities included incorporating these massive pipes into multi-service, stackable prefabricated modules, however the safety, buildability and cost benefits achieved by adopting articulated bellows in this configuration seemed worth highlighting for contractors and designers.

Contact our mechanical team if we can assist you with differential movement analysis and pipe riser design and certification.