What are the applicable scope of special bearings for highway bridges
The scope of application of special bearings for highway bridges is determined by their special functions and structural characteristics. The core is to adapt to the complex working conditions, special environments, and functional requirements of different bridges, and solve problems such as seismic resistance, large spans, curved layout, and stiffness adjustment that ordinary bearings cannot cope
The scope of application of special bearings for highway bridges is determined by their special functions and structural characteristics. The core is to adapt to the complex working conditions, special environments, and functional requirements of different bridges, and solve problems such as seismic resistance, large spans, curved layout, and stiffness adjustment that ordinary bearings cannot cope with.
1、 Seismic isolation bearings: suitable for high seismic risk and strong vibration demand scenarios
The core function of seismic isolation bearings is to reduce the damage to bridges caused by earthquakes by absorbing and dissipating seismic energy or extending the natural vibration period of structures. They are mainly suitable for high earthquake prone areas or bridges with high seismic resistance requirements.
2、 Spherical steel bearings: suitable for large-span, complex linear and special stress scenarios
Spherical steel bearings achieve flexible rotation through spherical force transmission, with high bearing capacity and stable rotational performance. They are suitable for bridges with large loads, multi-directional rotation, or complex linear shapes.
1. Core scope of application
Long span bridges: suitable for continuous beam bridges, rigid frame bridges, cable-stayed bridges, and suspension bridges with a span of ≥ 60m, capable of withstanding huge vertical loads and horizontal thrusts from the main beam of the bridge.
2. Complex linear bridges:
Curved bridge: able to adapt to the radial rotation and displacement of the bridge, avoiding uneven stress on the bearings.
Wide bridge (bridge deck width ≥ 15m): The spherical force transmission is uniform, which can reduce the local stress concentration of the support on the beam and pier.
3. Bridges in special environments:
Low temperature regions (-30 ℃ to -20 ℃): Steel structures are resistant to low temperatures and have no rubber aging issues, making them suitable for bridges in cold regions such as Northeast and Northwest China.
Coastal high corrosion areas: After using stainless steel sliding surface and anti-corrosion coating treatment, it can be used for cross sea bridges or coastal highway bridges.
Typical application cases: curved ramp bridges for highway interchanges, large-span continuous rigid frame bridges in mountainous areas, and approach bridges for urban river crossing bridges.
3、 Corridor sliding support: suitable for bridge corridor and large displacement coordination scenarios
Corridor sliding bearings are centered around universal load-bearing, vibration reduction, and large displacement adaptation, and are mainly suitable for bridge and building corridors, multi link bridges, or scenarios that require the release of large displacements.
1. Core scope of application
Connection between bridges and building corridors: For example, the nodes between urban elevated bridges and surrounding commercial buildings and transportation hubs need to coordinate the differences in settlement and temperature deformation between bridges and buildings.
Multi link long bridge: Suitable for continuous beam bridges with a length of ≥ 100m, it can release longitudinal large displacement caused by temperature changes (displacement can reach ± 200mm or more), avoiding beam cracking.
Steel structure bridges in high-intensity areas: Steel structure corridors or steel-concrete composite beam bridges, which reduce the impact damage of earthquakes on corridor nodes by embedding damping springs in the supports.
Key adaptation requirements: Complex nodes that require simultaneous universal rotation, large displacement sliding, and vibration reduction and energy dissipation, especially suitable for the installation of bearings for newly added corridors in the renovation of existing bridges.
4、 Variable stiffness support: suitable for scenarios with large differences in pier height and stiffness coordination
Variable stiffness bearings can balance the horizontal forces on various piers and abutments of bridges by adjusting the horizontal stiffness, and are mainly suitable for bridges with large differences in pier height or uneven structural stiffness.
1. Core scope of application
Bridges with significant differences in pier height: such as highway bridges in mountainous areas (some pier heights ≥ 30m, some ≤ 10m), by adjusting the horizontal stiffness of the supports, the horizontal stiffness of each pier (pier stiffness+support stiffness) tends to be consistent, avoiding excessive stress on the high piers and damage during earthquakes.
Asymmetric arrangement of bridges: such as irregular ramp bridges in interchanges, where the weight and span of the beam are asymmetric, resulting in uneven stress on each pier, can be balanced by variable stiffness supports to distribute horizontal loads.
Optimization of existing bridge stiffness: When reinforcing an old bridge, if the original bearing stiffness does not match the pier stiffness, variable stiffness bearings can be replaced to improve the overall seismic stability of the bridge.
2. Core function logic: Through "bearing stiffness compensation", the problem of uneven structural stiffness caused by differences in bridge pier height and cross-sectional dimensions is solved, ensuring that the forces on each pier and abutment are balanced under earthquake or vehicle loads.