Mechanical Engineering, bridge bearings, structural engineering Specialists In Structural Movement Control
Mechanical Engineers Specialising In Structural Movement Control
Supplied: Bearing supply, bridge jacking and bearing replacement works
West Sole Platform, WA-WAP Link Bridge
- Bridge Jacking & Bearing Replacement
Ekspan carried out an extensive inspection of the structural supports/
bearings on the trussed steel WA-WAP link bridge (approximately 38 metres
in length) on the West Sole platform. All visual findings (carefully measured,
photographed and cross-referenced against existing data) were assessed,
recorded and recommendations for future maintenance requirements were
provided in a report.
The existing bearings all appeared to be original PSC inverted mechanical
pot bearings that had been supplied circa 1983. The findings revealed these
bearings had reached the end of their design life and needed to be replaced.
Excessive corrosion and debris to bearing fixings, uplift brackets and
adjacent steelwork had caused stress on the bearings, which subsequently
resulted in skew, between bridge and jacket structures inhibiting movement.
Job Brief
Background Information
Project Team
Client: Perenco (UK) Ltd
Main Contractor: Ekspan
Start Date: 2015
Completion Date: 2015
Ekspan were appointed by Perenco to replace these mechanical bearings.
Prior to jacking and bearing replacement operations, temporary works had
to be implemented and included removal of the uplift restraint brackets.
Ekspan installed the approved jacking system (fabricated by CLS Offshore).
Each corner was individually jacked to a maximum height of 5mm enabling
the bridge’s position to be retained at the three remaining locations.
The inspection had confirmed a number of dimensional inaccuracies
associated with the original bearings. The main dimensional differences
related to the fixing hole centres and the overall base plate lengths for the
WAP end bearings. Ekspan manufactured 4 no bespoke mechanical pot
bearings (1 fixed and 3 guide) to suit the existing dimensions and load
criteria. The sequential methodology for bearing replacement and careful
monitoring throughout enabled successful completion of works while also
maintaining restraint between the bridge and the platform.
To prolong the bearing life stainless steel slide plates were fully welded to
the base plates, to prevent de-lamination.
Protective rubber skirts were installed to protect the sliding surfaces and
reduce the effects of debris ingress.
Ekspan's Workscope
Existing bearing prior to removal shows excessive corrosion
Bearing replaced complete with protective cover