Features Of The Bailey Bridge

The temporary steel bridge is generally called the prefabricated Bailey bridge. In many places, these two terms are mixed, and the Bailey bridge and the temporary steel bridge are even the same. Many websites directly put the steel bridge and the Bailey bridge on the title bar. Are they the same thing? Is there any difference? Strictly speaking, steel temporary bridge ≠ Bailey bridge, steel temporary bridge includes steel temporary bridge, only prefabricated steel temporary bridge = steel temporary bridge. The temporary steel bridge is defined by the manufacturing material. The main feature of the temporary steel bridge is modularity, and the scope of the temporary steel bridge is wider. From the literal understanding, it can be basically said that the main body of the steel structure can be called the temporary steel bridge. It's just that the steel temporary bridge is more typical and has the widest application. Relatively speaking, the term prefabricated steel temporary bridge is closer to the original meaning of steel temporary bridge, and it can also be said to explain what a steel temporary bridge is in another sense.

The convenient steel bridge is made of high-strength steel and is made up of lightweight standardized truss unit components and beams, longitudinal beams, bridge decks, bridge seats and connectors. It can be quickly assembled on-site with special installation equipment to be suitable for various spans and loads. Truss girder bridge. In the Second World War, it was used extensively in the battlefields of Europe and the Far East to repair bridges or erect temporary bridges. After the war, the Bailey bridge was improved and converted to civilian use. The improved version in the United States is named the Akroger bridge. The Chinese highway department uses 16mn steel to design and name the prefabricated highway steel temporary bridge. A set of equipment can be used to erect single-lane bridges with spans of 9, 12, 15...60, 63 meters. Class, crawler 50, trailer 80 load. This kind of bridge component is also widely used as construction support or tower.

The connection mode of the temporary steel bridge is different from the connection mode of other bridges. So, what are its characteristics?

1. The advantage of steel bridge welding is that it is convenient to use steel from any orientation, angle and shape intersection. Generally, there is no need for additional connecting plates to connect angle steel parts, and there is no need to open holes on the steel, so that the section will not be weakened. .

2. Bolt connection can be divided into ordinary and high-strength bolt connection. Advantages, easy installation, especially suitable for site installation and connection. Disadvantages, it is necessary to make holes on the plates and to align the holes during assembly, which increases the manufacturing workload; the bolt holes also weaken the cross section, and the connected plates need to overlap each other or add angle steel or assembling connecting pieces. Scrap steel.

3. Rivet connection; rivets are usually made of ordinary carbon rivet steel ML2 or ML3 with good plasticity and upsetting performance, and the hole diameter is used as the nominal diameter of the rivet. Plasticity, toughness and integrity are good, connection deformation is small, force transmission is reliable, fatigue performance when bearing load is good, and the quality is easy to check. Disadvantages: complex structure, large amount of steel, troublesome construction, loud noise when rivets, and poor working conditions.

Accessible steel bridges can be divided into beam bridges, arch bridges, steel bridges, cable-stayed bridges, suspension bridges, and hybrid system bridges according to the stress system of the main load-bearing structure.

1. Under the action of a vertical load, the main girder has only bending moments and shear forces in the cross-section of the girder, and no axial force is generated. The supports only bear vertical forces, not horizontal forces.

2. The biggest difference in the force of the arch bridge is that under the action of vertical load, in addition to the vertical reaction force at the two ends of the arch, there is also a horizontal thrust, which greatly reduces the bending moment and shear force in the arch. , Mainly under pressure.

3. The force of steel structure bridge has some characteristics of beam bridge and arch bridge, and the main load-bearing structure is eccentric compression and bending.

4. For cable-stayed bridges, the cables are under tension, the beams are bent, and the tower is under compression.

5. Suspension bridge, the meeting of the suspension cable only bears the tensile force.