What Are The Functions Of Bridge Expansion Joints?
In order to meet the requirements of bridge deck deformation, bridge expansion joints are usually set between two beam ends, between beam ends and abutments, or at the hinge position of the bridge. It is required that bridge expansion joints can be flexibly expanded and contracted in two directions parallel and perpendicular to the axis of the bridge. They are firm and reliable. Vehicles should run smoothly without sudden jumps and noise; they should be able to prevent rainwater and garbage from infiltrating and blocking; installation, inspection, maintenance, and removal of dirt should be simple and convenient. When setting the bridge expansion joint, the railing and the bridge deck pavement should be disconnected.
Generally speaking, bridge expansion joints mainly prevent the pavement structure from expanding and contracting due to temperature changes. In order to reduce earthquake disasters, expansion joints also play a role in preventing excessive beam displacement. In short, it is a device for buffering displacement.
The function of the bridge expansion joint is to adjust the displacement and connection between the superstructure and the bridge building materials caused by the vehicle load. Once the skew bridge expansion device is destroyed, it will seriously affect the speed, suitability, and safety of driving, and even cause public traffic accidents.
The width of bridge expansion joints is generally 20mm ~ 30mm, and the joints are filled with insulation materials. There are clear rules in the building structure standard about the distance between two expansion joints. If the plane size of the building is too long, it may cause excessive temperature stress in the structure due to thermal expansion and contraction. It is necessary to set a joint at a certain length of the structure to divide the building into several parts. This is the temperature joint.
For different structural systems, the distance between bridge expansion joints is different. It is very important to choose a proper expansion and contraction gap reasonably. The larger the gap, the easier it is to damage the elastic device. The gap is too large or too small, and the temperature of the equipment is not considered when adjusting the gap. Especially flat rubber elastic equipment is easy to damage. Even if it is a continuous bridge deck, the bridge deck pavement often has cracks.
Bridge expansion joints generally have a butt joint, a steel support type, a combined shear type (plate type), a modulus support type, and an elastic device.