To cross the rivers, streams and ravines, mankind from ancient times has used bridges of primitive type. With the development of civilization of the construction of bridges, they became more and more complicated and perfect, acquiring differences in the functional purpose. But something has not changed too much since ancient times-the wood remains the most common material for bridges of a simple design, which can be made with your own hand, since this material is easily amenable to machining, and the connection of parts of the structure is not difficult.
Of course, not any wood is suitable for construction, which is why it is worth paying attention to the wood of conifers, for example, such as spruce and pine, since they have a direct, even barrel, excellent physical and mechanical properties, as well as importantly, resistant to stable rotting.
To start building a bridge, you need a forest of various sections, both sawn and round. Logs, poles, quarters, lying, boards, bars, bars and horseman, here is an approximate list of assortment for building a bridge.
The simplest type of wooden is a beam bridge, which is used to block minor spans, which do not exceed 8-10 meters. The main elements of the bridge are span structures in the form of beams and support. The passing part of the bridge is laid on top of the runs and serves to take a mobile load. However, such a bridge will be absolutely useless if you need to pass heavier cargoes or travel through a small river. Therefore, instead of the beam bridge, it is necessary to use the bridge on the supports of the piles, which begins with the construction of pile supports.
