Mechanical Engineering, bridge bearings, structural engineering Specialists In Structural Movement Control
Mechanical Engineers Specialising In Structural Movement Control
Scope: Replacement of expansion joint -
supply and installation of 1 no
23m Ekspan TF 1300 expansion joint
M8 Fermoy Bypass Bridge, Ireland -
TF Expansion joint replacement
The Fermoy Bypass (circa 450m long) located on the M8 motorway approximately
20km north of Cork, is a multiple span concrete post-tensioned bridge carrying the
M8 motorway over the River Blackwater. The M8 forms part of the main link for
traffic commuting from Dublin to Cork city. This structure was built and is maintained
by Direct Route (contractors for the PPP Project M8 Fermoy/Rathcormac Bypass).
Following an in-depth independent investigation, requested by Direct Route,
findings revealed the existing joints on the southern abutment in both directions
had failed. Measurements and readings taken exposed considerable abnormal
shrinkage and creep on the joints, and prestress had caused elastic shortening
of the deck. The temperature differences and movement ranges had exceeded
the capacity of the movement joint for this bridge, making the existing joints nonfunctional and proving these, through collated data, to be either an incorrect
joint type or incorrectly installed. Direct Route required these joints renewing
with a suitable joint system to accommodate the more than originally anticipated
movement range for the M8 Fermoy Bypass.
Job Brief
Background Information
Project Team
Client: Direct Route (Fermoy) Ltd
Main Contractor: Ekspan
Start Date: August 2014
Completion Date: September 2014
Ekspan were approached by Direct Route to undertake a full inspection of the current
expansion joints on both north and south abutments to establish current conditions
and advise remedial works required. On submission of their report, Ekspan were
contracted to remove and replace the failed joints on the south abutment.
Ekspan’s inspection had also verified the failing of the south abutment expansion
joints and their incapability to achieve the designed bridge movements or
accommodate the bridge expansion gap between the deck and abutment ballast
wall. This inadequacy had forced the joint fixings to rotate and shear due to the
bridge’s large thermal movements and the loads/speeds of vehicles travelling across.
The joint was audible and sporadic bouncing was visible during transit. Eventually
this would result in the joint lifting out of the road, creating a catastrophic hazard to
motorists, especially motorbikes. The north abutment joints had deteriorated, not
to the same extent, but also required maintenance as these too were likely to fail
in the same way .
Ekspan’s programme of works was undertaken in three phases. These included
removal of the south abutment joints; installation of the secondary seal and
downpipes to suit the existing drainage arrangement and installation of one 23 m
TF 1300 over both carriageways. Remedial works were carried out on the north
abutment joints.
This project was successfully co-ordinated and completed in line with lane closures,
on time and to budget.
Ekspan's Workscope
Failed expansion joint - showing detachment from surface, delamination and joint exposure.
New installed TF1300 expansion joint
Completion of replaced expansion joint