Italian civil engineering company, Mavi, has deployed its Enerpac EVO multi-point synchronous lifting system for bridge bearing retrofit work on the Savio viaduct on the E45 road, in Emilia-Romagna, Italy.
Operating 12 Enerpac high tonnage, hydraulic cylinders, the EVO system is enabling Mavi to safely install new seismic isolators by synchronously lifting, holding and finally lowering the bridge decks.
Located above the Savio riverbed, the 1,890 m long viaduct follows the narrow, winding valley with spans ranging from 85 to 110 m resting on piers between 7 and 60 m in height. Retrofitting the viaduct involves replacing all existing bearings with unidirectional and multidirectional seismic isolators designed and manufactured by Mavi, and with friction pendulum isolators manufactured and supplied by another leading Italian company.
Working from pier to pier, Mavi uses the Enerpac EVO and 600 tonne capacity cylinders to simultaneously raise the two bridge deck ends resting on each pier, allowing access to the new bridge bearings. Loads at the end of each span range from 1,224 tonnes to 6,300 tonnes for piers 17 and 18, and 6,600 tonnes for pier 6.
“Lifting the bridge decks is a precise operation that requires careful and accurate control,” said a Mavi Srl spokesperson. “The combination of Enerpac’s EVO synchronous lifting system and high capacity cylinders means we are able to confidently lift loads that in some situations exceed 6,000 tonnes.”
The Enerpac EVO systems combines high-pressure hydraulics with a PLC-system to monitor and control precise movement and positioning of heavy loads. It allows a single device to control the entire lifting operation, providing status updates at every point of the process, without the need for manual monitoring.
For the Savio viaduct project, the Enerpac EVO control unit allows the 12 cylinders to be operated at differentiated pressures and constant volumetric rate, ensuring controlled lifts without inducing flexural-torsional stresses to the bridge deck.
The other key EVO features for this project include the pump’s ability to read stroke sensors, allowing the computer to read exactly how high the deck has been lifted, as well as control the pressure in each jacking cylinder to ensure a synchronous lift. Lifting is carried out with constant control and monitoring by means of centesimal measurement transducers and remote reading on digital equipment, up to a maximum of 10/12 mm.
For more information on the Enerpac EVO multi-point synchronous lifting system, visit www.enerpac.com.
For more information on Mavi Srl civil engineering, visit www.mavi-italia.com.
