Bridge installation by Self-Propelled Modular Transporter; what technical considerations are required for the permanent works in the temporary condition? What can a complex installation project look like?
As part of a 604 acre Beaulieu Park Development near Chelmsford, the RDR3 infrastructure improvement package included the replacement and significant enhancement of an existing access bridge provision with a new 160m three span steel concrete composite road bridge over road, rail, and combined foot and cycleway.
The bridge was installed using Self-Propelled Modular Transporters (SPMTs) over two weekend blockades and following a complex sequence of handling stages that enabled the transport from offline construction area to final position. The scheme minimised the disruption to road and rail infrastructure including the avoidance of any temporary works required to the Great Eastern Mainline railway infrastructure.
The new bridge is believed to be the longest structure of this type ever moved using SPMTs, but adding to this complexity, the deck has a plan radius (360m), asymmetric span lengths, and sits on a skewed abutment to the South, steeply skewed internal piers, and a square abutment to the North. The composite deck is of two pairs of heavily braced weathering steel girders and composite concrete deck.
The speaker led the design team that undertook the verification of the permanent works in the temporary condition and provided technical support to the contractor for coordination of the works. The presentation will discuss the technical details of analysing bridges supported on SPMTs and discuss the intricacies of the coordination between the capabilities of the heavy lift contractor, the permanent works structural requirements, and constraints imposed by other stakeholders such as National Highways and Network Rail. The Beaulieu bridge is used as a comprehensive example of the considerations required and discusses some practical solutions for geometry control.
Nicholas Lake, CEng MIStructE
Nick is a Principal Engineer at Tony Gee and Partners, based in the structures department in Esher. He has been team lead for design and checking of permanent and temporary works for steel, concrete, and composite bridges, jacked boxes, gantries, and various other heavy civils structures. He has a particular experience in finite element analysis including buckling and dynamic analysis of structures, and modelling of structures on hydraulic support systems. His involvement with numerous successful bridge launch, move, and slide schemes has also included site support and supervision.
For the Beaulieu bridge installation project, Nick led the detailed design verification in the various temporary conditions, and the design of associated permanent works strengthening and temporary works packages. He is also co-author of the Temporary Works Forum document TWf2022:01 ‘Self-Propelled Modular Transporters (SPMTs): A brief guide’.