Matière, a recognised player in the Philippines with more than 500 Unibridge® bridges built between 2008 and 2014, has just completed the design and construction of the San Juan viaduct to relieve traffic congestion in Manila. A look back at an exceptional work.
Home to over 12 million people, the capital region of the Philippines is one of the largest urban areas in the world. Reducing traffic jams has become a priority for the government, which must cope with a rapidly growing population. Faced with a very limited number of tunnels and major roads, finding solutions to decongest Manila has become an urgent necessity for the government.
It is in this context that the Filipino industrialist San Miguel launched in 2016 the construction of a 17 km urban viaduct crossing greater Manila from north to south. Matière was entrusted with the most technical section of this new structure: the San Juan viaduct, an exceptionally large “skyway” – six lanes over a length of 4 km – to be built on a river site within a short timeframe (two years). This was a complex project that required all of Matière’s expertise.
A structure with many challenges
We had to build a bridge with a low hydraulic impact, so as not to cause a significant rise in water levels during floods,” explains Claude Valdenaire, Bridge Engineer in the Philippines. This hydraulic constraint necessitated the design of single-column river piers, which required us to reduce the weight of the pier heads and decks as much as possible in order to withstand the strong seismic hazards of this region. For this reason, we decided to use steel headers similar in design to the Unibridge® beams, which are lighter than the concrete parts and form a lightweight deck superstructure. “Self-stable during installation and lightweight, Unibridge® beams also meet one of the major constraints of construction on river sites: weight. “Pre-stressed concrete beams could not have been transported on foot on barges because of their weight,” explains Claude Valdenaire.
Another challenge was to destroy existing bridges to ensure the passage of barges at night on the San Juan River and to restore one of them to working order during the day. A complexity that was perfectly mastered thanks to the modularity and ease of assembly of Unibridge® bridges, as Claude Valdenaire points out: “We had to destroy three bridges on the San Juan River to allow our barges and cranes to pass. We had to destroy three bridges on the San Juan River to pass our barges and cranes. We rebuilt them, including one with a Unibridge® mobile span, which allowed us to dismantle it easily to pass our barges at night and to reassemble it before sunrise to reopen it to traffic.
A success on all levels
Tight deadlines, controlled costs, construction on a river site… Matière was able to design the entire viaduct (infrastructure and superstructure) by meeting all the client’s constraints. The success of the project is based on Matière’s expertise and the performance of the Unibridge® caissons, which combine quality of manufacture, low cost and ease of assembly on site. The metal components are prefabricated in our factories in Europe, which saves time and costs,” says Claude Valdenaire. They are also easily transported by standard sea containers to the Philippines. Although assembly on site is quick and easy, it requires a high level of precision that only Matière can provide. “
Matière was also able to react quickly to a customer who often questioned its choices during the design phase. “From a simple pencil sketch on a map, we were able to create a quality design, adapt to the client’s changes of direction and manage the entire project right up to the opening of the structure to traffic,” summarises Claude Valdenaire. Another of Matière’s virtues is its collaboration with local companies, as well as with large local and international groups for the civil engineering.
Operational since December 2020, the San Juan viaduct is a fine showcase for Matière’s expertise. “Thanks to our unique Unibridge® concept, which is mainly manufactured in France and Belgium, Matière is able to offer the Filipinos a high-quality, durable structure, more quickly and at a lower cost than the large East Asian groups,” concludes Claude Valdenaire.