Structural Bearings

Types of Structural Bearings

Structural bearings are a key element in any kind of structure as they connect the superstructure with the substructure and transmit vertical and horizontal loads while allowing for limited rotation around any horizontal axis. MK4 bearings are widely used in structural and civil engineering applications, and particularly in bridges. They can be designed and manufactured for practically any load in a temperature range between -35ºC and 80ºC* and have actually been tested for vertical loads up to 100.000 kN.

MKSM is the best solution for structural bearings guaranteeing:

POT Bearings

— Used to take up large vertical loads and movements.

— Withstands much greater loads than elastomeric bearing.

— Movements allowed by internal sliding material and stainless steel.

— Rotations allowed by elastomeric disc confined in a steel POT.

— Deformation of the elastomer defines the rotation capacity.

— Rotation up to 30 mrad (with CE Marking).

— Connection of deck to piers: fixed, guided or free.

Spherical Bearings

— Used to take up very large loads, movements and rotations.

— Movements allowed by internal sliding material and stainless steel.

— Withstands greater loads than POT bearing.

— Spherical sliding surface defines the rotation capacity.

— Extremely low resistance to rotation.

— Rotation up to 50 mrad.

— Connection of deck to piers: fixed, guided or free.

Laminated elastomeric bearings

— Used for low to medium vertical loads and movements.

— Deformation capacity determines acceptable movements.

— Load capability decreases as movements and rotation increases.

— Selection of these bearings is better suited to small bridges.

— Made up of a series of elastomeric layers and steel plates
vulcanized at high temperature and pressure.

— Dimensions limited to allow for homogeneous vulcanization.

— Connection of deck to piers behaves like a spring.

Guide bearings and Restraint bearings

— Used to take up horizontal loads. No vertical load capacity.

— Made up of steel components.

— Steel/steel contact or sliding surfaces.

— Connection of deck to piers: fixed or guided.

MK4 bearings are widely used in structural, marine and civil engineering applications, particularly in bridges. Bearings are available in carbon steel as standard and in stainless steel for applications where corrosion is a potential problem. Each particular project has specific needs that require a tailored bearing for maximum efficiency at minimum maintenance.

MK4 bearings bearings are designed to meet the requirements of the European Standard EN 1337 and have consistently achieved the quality certification of the CE mark. Nevertheless, MK4 can also supply bearings complying with other international standards upon request, such as AASHTO or BS 5400.

Structural Isolation Products

Structural isolation products protect structures from the effects of big cyclic displacements such as those induced by an earthquake by isolating and damping the movement of the elements above them. A careful selection of materials and designs ensures that the vertical loads are still transmitted between the structure and the terrain while the device recenters by itself after the cycles cease.

Design and manufacturing

Our isolators are usually designed and manufactured following European (EN15129) standard and the indications from Eurocode 8. The effective stiffness and the efective damping depend on the design displacement (dmax); an iterative procedure is carried out until the difference between the assumed and calculated value of (dmax) are less than 5% of the assumed value. Protoype test of curved surfaces sliding material have been perfomed by acreditted laboratories like Eucentre.

Certificates

MK4 always works in the design and production process to ensure that bearings meet customer requirements and guarantee optimal quality. MK4 quality system is certified according to ISO 9001:2015. MK4 POT; elastomeric spherical bearings; guide have the CE Mark qualification, which confirms that all bearings are manufactured according to EN 1337-5; EN 1337-7; EN1337-1; EN1337-2; EN1337-3; EN1337-8 standards.
The quality and conformity of the bearings are regularly checked according to different standards (AASTHO, BS, DIN, EN 1337, …) in accredited laboratories.