The Department of Public Works and Highways (DPWH) has employed the latest in construction technology to raise the Ayala Bridge in San Miguel, Manila while also making it resistant to earthquakes.
Using the strand jack technology, a heavy lifting system used worldwide to lift bridges, buildings and other structures, the bridge’s freeboard clearance was raised by .70 meters in order to allow barges and other large water vessels ferrying goods to pass under it.
The substructure of the bridge’s road approaches were also retrofitted in order to conform with the current seismic code based on the agency’s Urgent Infrastructure Development Project (UIDP).
In order to ensure that the four lane steel truss-type Ayala bridge will be earthquake-resistant, two seismic engineering tools - high-damping rubber bearing and base isolation.
The installation of high-damping rubber (HDR) bearings will allow the bridge to absorb energy during an earthquake by transforming energy to heat while the base isolators divide the bridge’s fixed connections to substructures, letting the roller bearing on sides of the bridge to make way for movement.
The upgrade and rehabilitation of the Ayala Bridge will cost approximately Php 447.953 million and according to the DPWH, it may be partly re-opened to light vehicles by mid-May 2015.