Is the overpass a bridge or not?

Bridges, overpasses, overpasses, viaducts - all these words are synonyms. And they denote very similar building objects, widely used by man in his economic activities. To distinguish between these concepts, this small material is also proposed.

Bridge

This is an engineering structure, invented for a very long time. One of the oldest dates from the thirteenth century BC. Since ancient times, people have started building bridges to overcome water barriers such as rivers, lakes, marshes, etc. Therefore, the word is not only the most used among the proposed, but also the oldest. In a broad sense, all the other buildings mentioned are bridges, so the question posed in the title of the article should be answered "yes." However, there is a "but". About it a little later.

Pursuit

This building, which is built over another road, but is no longer a bridge, because there are technologically significant differences from it. First of all, they are caused by the fact that when designing a viaduct there is no need to take into account the influence of various natural phenomena associated with the watercourse available under the bridge. Therefore, the principle of creating supports in this case differs radically. We will not delve into the technical details, we recall only three factors that the head of bridge designers is hurting. This is an ice drift, erosion and the bulk of ships passing under them. The overpass is, in fact, a bridge over the usual road. Therefore, we have another term for this structure. This is the small "but" in the legitimacy of the use of the word "bridge" in determining the overpass.

Overpass

If for the construction of an overpass, it usually takes from two to four spans of 10-30 meters in length, then for the laying of the overpass usually more is needed. In fact, this is the difference between these engineering structures. However, the important point here is that the flyover can cross several types of obstacles at once, for example, it can be a river, road and railways at the same time, thus combining both the bridge and the overpass.

Viaduct

Consider the following type of bridge. There is another type of obstacle, fundamentally different from those we have already considered. This includes ravines, ravines, ravines. Therefore, the word "overpass" can no longer be used here. This is another kind of bridge structure - the viaduct. Let's consider its features.

The construction of viaducts instead of ordinary roads is justified in cases when it is economically impractical to create a mound. That is, everything is determined by the depth of the ravine, as well as by its length in the profile of the transport route. Thus, the difference of the viaduct from the overpass will be the absence of a more or less even surface under the bridge. Due to this factor, the uniformity of supports and spans in this case is no longer suitable. Viaducts are usually very beautiful and majestic structures. For example, the height of one of the pillars of the world's highest viaduct Millau is about 340 meters.

Continuing the topic, you can mention another interesting building, although it has only a remote relation to such concepts as overpasses, roads. We are talking about the so-called aqueducts. It is analogous to a viaduct, only for carrying water, not vehicles, over the same ravine, river or other obstacle, usually part of the irrigation system.

Conclusion

Returning to the question posed in the title of the article, we finally answer it. Yes, the overpass is a bridge on the principle of construction, and no, because it is not created above water barriers, but over a similar road surface. Such is the dialectic.