It was the Senegalese President himself, Macky Sall, who inaugurated the Unibridge® Famara Ibrahima Sagna Bridge in Marsassoum in February 2023. Let’s look back at this technical achievement and this historic moment for Matière® and the citizens of the Sédhiou region.

On 28 February 2023, Senegalese President Macky Sall inaugurated the Unibridge® Famara Ibrahima Sagna Bridge in Marsassoum. This is an important date for the population of the Casamance region in southern Senegal. The bridge will completely open up the Sédhiou region and facilitate its economic and social development.

From ferry to Unibridge® bridge

Previously, the inhabitants had to use a ferry to cross the river,” explains Thomas Rivalta, Manager of Matière® Senegal. It only operated every hour between 8am and 6pm. Since the opening of the Unibridge® bridge, crossing the river takes only 10 minutes, and at any time, day or night. This saves users a considerable amount of time and gives them more flexibility when travelling. It took 24 months to complete the 2×1 lane structure, which is part of the company’s 2018 contract to build 18 bridges.

Technical constraints

As a region of estuaries, Casamance contains poor quality organic soils with a preponderance of silt. To build the roads on this muddy soil, the company had to carry out several phases of soil consolidation with concrete foundations driven by piles up to 40 m deep to allow the bridge to be anchored in rigid soil. The other challenge of this work was to maintain the pace of execution despite the heavy rainfall in the region. The use of Unibridge® made it possible to meet these deadlines despite the geotechnical difficulties of the soil.

Contributing to the economic and social development of the region

During the official inauguration, President Macky Sall emphasised the strategic importance of this bridge located in a natural region surrounded by hectares of forest and multiple waterways. As part of the policy of opening up the region, this structure will also have a significant economic impact by facilitating the transport of goods in remote areas, thus enhancing the economic potential of the region (mango, forest products, horticulture, fishery products). As for the name of the bridge, Famara Ibrahima Sagna, it immortalizes the economic and intellectual career of this man, who was several times Minister and Honorary President of the Economic, Social and Environmental Council.

Promoting Matière®’s know-how

The Famara Ibrahima Sagna Bridge, with its 485 m of linear length and its technical nature, is a great reference for Matière®. “It is a great honour for the company to have carried out this work, which demonstrates our know-how and our ability to work with the local workforce trained to use our techniques and know-how,” says Thomas Rivalta. In fact, to complete the contract for the 18 bridges, we opened an agency in Dakar in 2018 and set up a prefabrication plant for concrete elements on the outskirts of Dakar.

Of the 18 bridges in the contract, 12 have been delivered. By April 2024, the company will have completed the contract. For MATIERE, this is certainly a race against time, but above all a great source of satisfaction, as these structures are strategic for opening up Senegal and facilitating trade.

By 2050, the population of Senegal is expected to increase from 7 million to 30 million. And the population is expected to double in Africa by 2050, so it is essential to develop the infrastructure and we are proud to be part of it.

Thomas Rivalta

The Keur Gorgui overpass in Dakar was the first work delivered by Matière^® under its €209 million contract with the Senegalese government to build 18 bridges and overpasses. Here is a look back at this critical stage, the success of which confirmed the client’s confidence.

On 1 April 2020, the Keur Gorgui autobridge on the northern highway (VDN), one of the three main roads leading to the economic heart of Dakar, was opened to traffic. This is a real benefit for the inhabitants, as traffic was particularly difficult there. No provision had been made to allow motorists to exit the expressway and join the VDN,” explains Thomas Rivalta, Matière^® project manager. The construction of the Keur Gorgui overpass was intended to restore fluidity to these intersections in order to avoid traffic jams. We were in charge of the structure, the connection of the bridge to the existing roadway and the development of the roundabouts and ramps located under the bridge. ” 

The first of a long series: 

Although the construction of this bridge did not present any particular technical challenges for the Matière^® teams, managing this project and setting up an organisation dedicated to a much larger project was not an easy task. The Keur Gorgui overpass was part of the major road infrastructure improvement project entrusted by the government to Matière^® in 2018 to improve mobility in the Dakar region in particular. We had to succeed in this first stage, while at the same time creating a local subsidiary dedicated to the construction of the 18 engineering structures within 44 months,” explains Thomas Rivalta. We had no room for error and had to prove to our client that he was right to choose us. The pressure was high because this was our first collaboration.

Major projects require major resources!

Matière^® had to recruit the right profiles from among the Senegalese resources and train them in Unibridge^® techniques but also in the company’s specificities. “It wasn’t so much a question of skills as adaptability to our way of working and our corporate culture, says Thomas Rivalta. We are an agile family business, with specific niche trades. Each employee must be flexible and able to step outside their job description if necessary. This ability to adapt to the need and to do everything possible to ensure that the project progresses are the real strengths of Matière^®. And it is this state of mind that we have tried to transmit to our Senegalese employees. ” 

Another challenge that Matière^® has mastered is how to get people from different cultures and backgrounds to work effectively together. On the one hand, there are the teams in France (design offices, the frame manufacturing plant and the purchasing and logistics department) and on the other, the teams in Senegal (sales office, heavy prefabrication plant for the ramp and employees on the site).

Need to go fast:

The work on the Keur Gorgui autobridge had an impact on the lives of users, who took longer to get to their workplaces. Matière^® tried to limit this nuisance as much as possible with optimised construction methods and organisation of the work. Its objective was clear: to have the fastest possible intervention on site in order to free up the roads as quickly as possible and ease the traffic flow. This is why we chose to build Unibridge^® modular bridges, which are easy and quick to assemble,” notes Thomas Rivalta. We also took care to use equipment adapted to the outdoor environment, as we had little space for assembly.”  

A great success: 

Matière^® is very proud of the Keur Gorgui overpass, which was successfully delivered during a complex project launch phase for the construction of the 18 structures. “Our client trusted us in the choice of construction methods and the Unibridge^® product, concludes Thomas Rivalta. We had to confirm this trust by building the structures quickly and on time.” 

With Keur Gorgui, Matière^® has helped improve traffic flow at crossings on the VDN and offered the inhabitants a beautiful structure. With its pedestrian areas, benches and green spaces, the overpass fits perfectly into the urban context. Three other bridges have been delivered since Keur Gorgui was opened to traffic, marking the end of the first major phase of one of the largest road development projects in Senegal.

The Keur Gorgui autobridge is:

• A double bridge with two lanes
• 202 metres long
• 10 metres wide for each bridge
• A Unibridge^® steel structure

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.

The Senegalese government has begun a vast project to provide the country with modern road infrastructure. As part of the implementation of the Emerging Senegal Plan (PSE), Matière^® has been entrusted with the design and build of 18 Unibridge^® bridges and flyovers that can be erected very quickly. Started in August 2018, let’s take a look at the progress of the works. 

Major infrastructure project in Senegal

The city of Dakar is facing serious urban traffic problems. As part of the opening up and improvement of urban mobility, the Senegalese government has entrusted Matière^® with the design and build of around ten flyovers, including severals on the “Voie de Dégagement Nord (VDN)”.

A total of 5,390 linear meters of bridges and 11 km of slip road will be built in order to relieve congestion of Dakar traffic, which is particularly dense at certain times of the day, but also to improve urban mobility in densely populated areas. 

Construction of flyovers: Dakar’s traffic is growing in height 

In the Dakar metropolitan area, the first works on the VDN, the capital’s structural axis, were delivered on schedule, in fact 5 months ahead of schedule (the work on the Saint-Lazare flyover, which was scheduled to last 18 months, will in the end take only 13 months). Proof of Matière^®‘s technical know-how during the execution studies, but also during the manufacture and installation of the metal structures. 

The two flyovers built in 2×2 lanes are already open to traffic. The flyover of Keur Gorgui’s Cité, with an overhall length of 202-metre, is operating since April 2020. On the other hand the 404-metre Saint-Lazare flyover was inaugurated on July 2^nd last by the Minister of Infrastructure, Land Transport and Opening-up, so ten months after the beginning of the works.. A situation that considerably improves mobility in this part of the Senegalese capital.

But the project does not stop at the extension of the VDN in the heart of the city. Other works are planned, particularly in the regions. The construction of five bridges is planned in the south and east of the country, with the aim of opening up certain regions to the population and local economic development.

A prefabricated steel reinforcement and precast concrete plant created in Diamniadio

This is not the first intervention of our teams in Senegal. Matière^® factories in Belgium and Le Creusot were used to manufacture all the components (the entire deck of the Marsassoum Bridge was manufactured in Le Creusot). 

In addition to the Senegalese companies involved in the construction of those infrastructures, a Matière^® steel prefabrication and precast concrete unit were created. In Diamniadio, 300 people are working daily to build  precast retaining walls and slab deck. The assembly is carried out on site, after simplified controls, which results in a substantial saving of time. 

Unibridge^® modular bridges

In order to meet the specifications, the steel structures are built using Unibridge^® technology, the concept of prefabricated metal bridges box girder invented by Matière^®. This system is innovative in its design, original in its functionalities (modularity of geometry, possible evolution over time) and in the very rapid assembly methods used. Indeed, the panels and multiple parts give way to 11.40 metre long watertight boxes. More sophisticated, more modular, more aesthetic too, they can be transported in shipping containers, easily assembled on site by crane or ground handling. 

The preservation of the environment is also taken into account. 

The preservation of the environment was also taken into account in this project led by Matière^®. In addition to improving urban mobility, the works contribute to the development of a better living environment for local residents. The construction works of Dakar’s flyover also forsee urban and landscaping development around the structure, with paved and vegetated surfaces, pedestrian walkways, playgrounds, etc. 

This new reference is an excellent showcase for Matière^®‘s know-how, where the skills and talents of our teams are expressed.