Riverside Expressway (REX) is located next to the CBD of Brisbane and on the northern bank of the Brisbane River. It is a major arterial road in and out of the Brisbane CBD. REX consists of a series of bridges which are simply supported on the piers, which were constructed in early 1970s’. The existing bearings on the bridge are nearing the end of its life and as such there is a requirement to replace the bearing to ensure the continued use of the expressway.
The original design of the bridge had not provided any recesses for the hydraulic jacks to lift the bridge in order to gain access to the bearings. As such there is a need for a structural system that will provide a support for the jacks.
Madsen Giersing (MG) was appointed by the Department of Transport and Main Roads (DTMR) to provide the detail design and technical support services for the bridge jacking support falsework and personnel access platform for replacement of bearings on the Riverside Expressway.
The project had a number of challenges. The main were the support of the jacking falsework system without drilling anchors into the existing structure, the personnel access platforms were not to be supported off the jacking falsework and the system was required to accommodate a wide range in bridge girder numbers, column sizes and spacing’s. In order to overcome these challenges a column friction clamp was designed to support the jacking beam and thereby alleviating the requirement for drilling into existing columns. The jacking falsework and personnel access system was modularised in order to minimised the items required for the different bridge spans
The design of the bridge falsework jacking system was undertaken in close collaboration with DTMR due to the critical nature of the friction clamp design. DTMR undertook a full scale test on the friction clamp in order to validate the design. The test showed that the clamp was able to successfully sustain 1.5 times the anticipated maximum load.
Eastbound Span 23, weighing approximately 630t, was the first span to be lifted. The bridge span was successfully lifted, the bearings replaced and the span set down during a 56 hour window from Friday night to Monday morning.
Department of Transport and Main Roads Queensland