Custom Elastomeric Bearings: Technical Solution for the Puente de la Pepa in Cádiz

Custom-made elastomeric bearings. The 1812 Constitution Bridge, popularly known as the Puente de la Pepa, is one of Spain’s most complex and spectacular engineering feats. As it is a high-rise cable-stayed bridge spanning the Bay of Cádiz, the selection of structural components was critical.

In this project, the use of large-format custom-made elastomeric bearings proved essential to manage massive loads and ensure the stability of this vital infrastructure that connects the city to the mainland.

The Pepa Bridge and the need for special support

This structure is the third access point to Cádiz and stands out as one of the tallest bridges of its kind in the world. Due to its cable-stayed design, the distribution of stresses differs from that of conventional viaducts. Although this type of bridge requires fewer support points, these must be capable of withstanding extraordinary stresses.

As specialized suppliers, at Cacesa we handled the custom-designed elastomeric bearings specifically for the structure’s pillars. The client, an engineering firm with whom we had already collaborated on international projects, trusted our ability to solve a challenge of extraordinary dimensions.

Challenges in the manufacture of large tonnage parts

The main challenge of this project was not only the chemical composition of the rubber, but also the physical size of the pieces. We are talking about supports that reached a weight of between 3,000 and 3,500 kilos per unit.

1. Handling and precision in vulcanization

Manufacturing custom elastomeric bearings of this weight requires highly sophisticated internal logistics. Because they are such massive blocks of rubber and steel, the vulcanization process is extremely delicate:

Heat management: It is necessary to ensure that the vulcanization temperature reaches the core of the part homogeneously without degrading the outer layers.
Plate precision: In pieces weighing more than three tons, the manual placement of the vulcanized steel plates must be perfect to avoid deviations in load capacity.
Production risk: Due to the cost of materials and the time invested, there was no margin for error; each piece had to be perfect the first time to meet profitability and deadline standards.

2. Large format machinery (2×2 meters)

The reason Cacesa was chosen for this project lies in our production capacity. Manufacturing these custom elastomeric bearings requires presses with dimensions that are not standard on the market:

Working surface: We have 2×2 meter machines that can accommodate the gigantic molds needed for the Puente de la Pepa.
Opening capacity: Our machinery allows openings of up to one and a half meters, facilitating the demolding and safe handling of 3,500 kilo pieces.

Bridge engineering and compliance with EN 1337 standards

The safety of an infrastructure that supports constant traffic to Cádiz cannot be left to chance. Therefore, all our custom-made elastomeric bearings are manufactured in accordance with the strict EN 1337 standard.

This European regulation guarantees that the structural supports have passed tests of:

Compressive strength: Supporting the weight of the deck itself and the dynamic traffic loads.
Rotation capacity: Allowing the structure to adapt to movements without generating cracks in the pillars.
Durability in marine environments: The rubber is formulated to withstand the salinity and extreme humidity of the Cadiz coast.

Furthermore, the CE marking seal confirms that each unit delivered has passed rigorous quality controls, ensuring a lifespan exceeding several decades of flawless service.

Results after more than a decade of service

The Puente de la Pepa bridge is now a firmly established feature of the Cádiz landscape. After years of operation, the custom-made elastomeric bearings supplied continue to function without any technical issues.

In our philosophy as manufacturers, success is measured by the absence of any customer feedback: if the supports don’t require corrective maintenance before their expected lifespan, the work has been excellent. This project reinforces our specialization in large parts, where technical expertise and the right machinery make the difference between a standard component and a high-level engineered solution.

Conclusion: Leaders in tailored support solutions

Our involvement in the 1812 Constitution Bridge demonstrates that Cacesa is the ideal partner for projects where scale and technical complexity are critical. The supply of custom-made elastomeric bearings for this project is a testament to our ability to tackle monumental challenges with meticulous craftsmanship.

Elastomeric Bearings for Viaducts of the Doha Metro

The Doha Metro represents one of the most impressive milestones of modern engineering in Qatar. In a project of this magnitude, the choice of elastomeric bearings for the viaducts was no small matter. These components are responsible for absorbing structural movements and ensuring the safety of thousands of passengers daily.

In this article, we analyze how technical specialization and compliance with EN 1337 standards allowed this project to become an international benchmark of success.

The Doha Metro: A road infrastructure of monumental scale

Road infrastructure in the Persian Gulf presents challenges not found in Europe. The design of the Doha Metro, with its long elevated sections, demanded a support system capable of withstanding extreme conditions. Here, elastomeric bearings for viaducts act as the vital link between the decks and the structure’s piers.

Climate challenges at the Qatar viaduct

Building a viaduct in Qatar means subjecting materials to temperatures exceeding 50°C. This temperature range causes constant expansion in the concrete. To address this, a specific rubber compound was developed that maintains its elastic properties under scorching heat, ensuring that the supports do not crystallize or lose load-bearing capacity.

Bridge Engineering: The Science Behind the Type C Bearing

In bridge engineering, the C-shaped bearing is recognized for its reliability. These devices incorporate vulcanized steel plates inside the elastomer, which allows for:

Withstand massive vertical loads: Ideal for heavy rail traffic.
Allow horizontal deformations: Absorbing the effects of the subway’s braking and acceleration.
Compensating for rotations: Crucial when the viaduct crosses curves or uneven terrain.

The use of these elastomeric bearings for viaducts in Doha has shown, after 10 years of use, that durability is the best investment in maintenance.

Compliance with EN 1337 Standard and CE Marking

Safety in mass public transport leaves no room for error. Therefore, every unit manufactured for this project complied with EN 1337. This European standard is the most demanding in the world for structural supports, defining everything from the purity of the rubber to the strength of the steel sheets.

The CE Marking Guarantee

CE marking was a non-negotiable requirement for the Barcelona-based engineering firm that led the bidding process. This certification guarantees that the products have been laboratory tested under shear and accelerated aging conditions. For Cacesa, offering fully certified materials was the key that opened the doors to the Qatari market, giving them an edge over American and Asian competitors.

“Pharaonic” Logistics: Production under pressure

One of the key points of the interview with our technical team was the management of deadlines. In a project of this scale, the volume of elastomeric bearings for viaducts required was immense.

Intensive production: Special shifts had to be organized to meet the customer’s delivery dates.
Holiday coordination: Much of the manufacturing coincided with the month of August, which required masterful human resource planning.
Financing and Collections: An export project requires financial stability to manage cash flows while the material travels to the Gulf.

Why does the Doha Metro remain a benchmark?

Today, the Qatar viaduct is an example of how Spanish industry can lead global projects. The key was not just manufacturing a component, but understanding the project’s ecosystem: the engineering needs, the demands of the climate, and the rigor of modern road infrastructure.

The lifespan of these components is extremely long, reducing the need for post-construction interventions. This is vital in elevated viaducts where access for replacing a support is costly and complex.

Conclusion: Quality that crosses borders

The successful supply of elastomeric bearings for viaducts on the Doha Metro confirms that the combination of EN 1337 compliance and logistical adaptability is unbeatable. At Cacesa, we remain committed to technical excellence to support the major infrastructure projects of the future.

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