What are the applications of modular single joint expansion devices on urban bridges
Modular single joint expansion devices are widely used in urban bridges, and their design features (suitable for small and medium displacement, compact structure, and good driving smoothness) are highly compatible with the operating environment and functional requirements of urban bridges. The main application scenarios include the following:
Modular single joint expansion devices are widely used in urban bridges, and their design features (suitable for small and medium displacement, compact structure, and good driving smoothness) are highly compatible with the operating environment and functional requirements of urban bridges. The main application scenarios include the following:
1. Beam end joints of medium and small span beam bridges
Expansion devices need to be installed at the joints of simply supported beam bridges (such as precast slab beam bridges, small box beam bridges) and continuous beam bridges that exist in large numbers in cities, as well as at the joints between beam bodies and bridge piers, and between adjacent beam bodies. Due to the small span of such bridges (usually 10-30 meters per span), the displacement caused by temperature, load, etc. is not significant (the displacement of a single joint is mostly between 0-80mm). The modular single joint expansion device can accurately match its displacement requirements while ensuring a smooth bridge deck.
For example, in river crossing simply supported beam bridges on urban main roads and prefabricated slab bridges in branch roads, single joint expansion devices are used at the joints of the beam ends to absorb the expansion deformation of the beam body, avoiding gaps or misalignment on the bridge deck.
2. Connection between bridge and abutment
The bridge pier is the connecting structure between the bridge and the embankment, and there is a necessary displacement difference between the beam (especially the simply supported beam) and the bridge pier (such as the expansion and contraction of the beam and the settlement difference of the bridge pier). The modular single joint expansion device can effectively buffer the relative displacement between the bridge abutment and the beam body, prevent cracks caused by forced compression, and avoid the phenomenon of "jumping" when vehicles pass through, ensuring driving safety.
Urban bridge piers often use buried or lightweight abutments, and the compact structure of single joint expansion devices can adapt to the limited space between the abutment and the beam, simplifying the installation process.
3. Segments or small radius curved sections of elevated bridges
Urban elevated bridges (such as expressways and overpasses) often adopt multi link continuous beam structures, and expansion devices need to be installed at the joints between links. Due to the extremely high requirements for smooth driving of elevated bridges (reducing noise and vibration, avoiding affecting surrounding buildings), the flat surface and stable expansion performance of modular single joint expansion devices can meet this demand.
For small radius curved bridges, single joint expansion devices have strong adaptability and can be adjusted to match the curve direction by fine-tuning the angle, ensuring sealing and uniform force distribution at the joints.
4. Bridge deck joints of urban underpasses or underpasses
The top bridge deck of urban underpasses (such as underpasses crossing railways and main roads) or underground passages needs to withstand ground vehicle loads, while also experiencing displacement due to changes in structural depth and surrounding environmental temperature. The modular single joint expansion device can not only absorb displacement here, but also prevent rainwater and sediment from entering the interior of the tunnel through sealing design, protecting structural safety.
5. Joints of pedestrian overpasses and landscape bridges
The load of urban pedestrian overpasses is relatively small, but they have high requirements for pedestrian comfort and landscape. Modular single joint expansion device has a small volume and simple appearance, which can be coordinated and unified with bridge deck pavement, reducing damage to the landscape; At the same time, its smoothness can avoid bumps when pedestrians walk, enhancing the experience.
In landscape bridges, if small and medium span designs are adopted, the lightweight and easy to maintain characteristics of single joint expansion devices also make them preferred.