Traditional Culture Encyclopedia - Traditional virtues - The types of bridges are?

The types of bridges are?

The four basic types are girder bridges, pontoon bridges, cable-stayed bridges and arch bridges. Girder Bridge. Also known as the flat bridge, spanning the empty beam bridge, is to the piers as a horizontal distance support, and then frame girders and flat pavement of the bridge. This is the most common application of a bridge, in the history of the other bridge shape appeared earlier. It has wood, stone or wood and stone mixed forms. Pre-qin when the beam bridge are made of wooden pillars piers, but this wooden pillars wooden beam structure, very early to show its weaknesses, can not adapt to the development of the situation. Therefore, instead of stone pillars and wooden beam bridges, such as the long multi-span bridges built during the Qin and Han Dynasties: Wei Bridge, Ba Bridge, etc.. The invention of piling technology around the time of the Han Dynasty led to the emergence of stone piers, signaling the ability of bridges made of wood and stone to cross wider rivers and withstand the impact of surging waves. But because of the stone piers on the wooden beams are not resistant to wind and rain erosion, so they built a bridge house on the bridge, to protect the bridge, this bridge type (corridor bridge) after the South, but the earliest are seen in the Yellow River Basin. Small and medium-sized stone beam or slate bridge, easy to construct, durable materials, maintenance and labor-saving, is the most popular folk bridge form, especially after the Southern Song Dynasty, very prevalent in the Quanzhou region of Fujian, creating a lot of grown-up stone beam bridge. Beam bridge if there is no pier in the middle, said single-span beam bridge; if there is a pier in the water, so that the bridge to form two holes, it will be called double-span beam bridge; if more than two piers, it will be called multi-span beam bridge. Pontoon bridge. Also known as boat bridge, pontoon navigation, floating truss, because it is easy to set up, often used for military purposes, it is also known as the "war bridge" - a wooden boat for dozens of hundreds of ships (also useful rafts or rafts across the water) chained together and lined up on the water surface, the boat paved boards for the horses and men to and from the passage of the bridge. If the strict sense of the bridge: is to span the air and have piers as a sign, then it is not the full meaning of the bridge. Pontoon bridge is mainly built in the river is too wide and too deep or ups and downs of the river, not the general wood and stone pillar and beam bridge can help the place. Pontoon bridge on both sides of the pile or iron cattle, iron mountain, stone grants, stone lions, etc. to tie the cable. Sui Daye first year in Luoyang Luo water on the completion of the Tianjin Bridge, is the first time with iron chains connected to the ship's pontoon bridge. Pontoon bridge is still commonly used in the south of China, such as Jiangxi, Zhejiang, Guangxi and other places. Advantages of pontoon bridges: First, the construction is fast, the Qing Xianfeng two years (1852), the Taiping Army siege of Wuchang, only one night time to build two pontoon bridges across the Yangtze River. Second, the cost is low, the Ming Dynasty Zou Shouyi in the "repair Fenglin pontoon bridge," in the stone bridge and pontoon bridge has done a comparison: "If you use the stone beam bridge, to cost a thousand gold, and with the pontoon bridge, the cost of 500 gold can be, according to the need to decide." Third, open and close at will, demolition and erection are very convenient. The disadvantage is that the load capacity is small, with the wave up and down turbulence, and the ability to withstand flooding is weak, often need to timely dismantle the withdrawal, and to be cared for, the management of cumbersome, boats, bridge boards and mooring cables should be often repaired and replaced, maintenance costs are expensive. Therefore, the final destination of many pontoon bridges, are to wooden beam bridge, stone beam bridge or stone arch bridge development. Rope Bridge. Also known as suspension bridge, rope bridge, suspension bridge, etc., is a bamboo or rattan rope, iron rope, etc. for the backbone of the splicing suspension of the bridge. More than built in the water is not easy to do the piers of the steep banks of the dangerous valley, mainly in the southwest. The practice is to build houses on both sides of the house, the house each set up the rope of the column and the rope of the column, and then a number of thick ropes laying fastening, and then in the rope on the horizontal pavement boards, some on both sides of the rope is also added to two as a handrail. Beginning in the Qin and Han Dynasty, such as the Qin Li Bing was built in Sichuan Yizhou (now Chengdu) southwest of the city of a board bridge, also known as "Yili Bridge", is a bamboo bridge. Existing famous Luding iron rope bridge built in the Ming and Qing Dynasties, irrigation county bamboo rope bridge and so on. Over the rope bridge feel very thrilling, as the ancients described over the rope bridge as: "people hanging in mid-air, the degree of their decision to the gully, a moment without warning, fall bottomless valley." Tang Dynasty monk Zhimeng said: "I can not see the bottom, the shadow of the battle." In fact, the real ferry is still safe, as "Xu Xiake travel record" of Guizhou Panjiang Bridge evaluation of the same: "look at the floating, trampled on it is standing still." Arch bridge. Appeared late in the history of China's bridges, but once the arch bridge structure was adopted, it developed rapidly, and became the most vital of the ancient bridges in a bridge type, even today, it still has a broad prospect for continued development. Arch bridge has a stone arch, brick arch and wooden arch, of which the brick arch bridge is rare, only in the temple or garden occasionally used. Generally common is the stone arch bridge, it has a single arch, double arch, multi-arch points, the number of arches depending on the width of the river to determine. General center of the arch to be particularly tall, the two sides of the arch to be slightly smaller. According to the shape of the arch, there are five sides, semi-circular, pointed arches, Tan arch and so on. The bridge deck is generally paved with stone slabs, and the bridge side is made of stone railings. The image of the arch bridge was first seen in the Eastern Han Dynasty on the portrait bricks, is by the stretching arm of the wooden stone beam bridge in the development process and by the tomb arch, water pipe and other shapes. Documentation is found in the north and south dynasty in the "water Jingji", the earliest surviving objects and the most representative of the Sui dynasty Li Chun designed and built Zhaozhou bridge. Stone arch bridge coupon, after the Ming Dynasty, especially in the Qing Dynasty, the prevalence of the whole coupon, that is, "barrel-shaped coupon". Cable-stayed bridge Concrete cable-stayed bridge Combined girder cable-stayed bridge Steel cable-stayed bridge Other shapes: Flying Pavilion and trestle, channel bridge and fiber road bridge, as well as curved bridges, fish swamp flying beams and fengshui bridge. "Flying Pavilion", also known as the pavilion road, compound road, that is, the footbridge. Ancient palaces and pavilions across the channel between. The three auxiliary yellow map: "was in the palace (refers to the han weiyang palace) west across the city pool for the flying pavilion through the jianzhang palace, constructing the emperor's carriage road above and below." Qin and Han Dynasty Palace buildings and halls to the Court Road passes, because of the up and down the road, so it is called Fudao. Qin Shihuang built the pavilion road from Afang Palace to Mount Li, people walk on the bridge, the car under the bridge, can be called China's earliest overpass. "Trestle Road", also known as Trestle Pavilion, Bridge Pavilion, single-armed wooden beam bridge. In the steep mountainous areas, paved roads. "Channel bridge", both water diversion channels and bridges for pedestrians. That is, in the bridge to build aqueducts to draw water. Such as built in the Jin Dynasty in Shanxi Hongdong County Huiyuan Bridge. So now Shanxi folk still have "water bridge, bridge water" slang. "fiber road bridge", a kind of easy to pull the fiber and build, and the river parallel to the band of long bridge. Mostly found in the canal area in Zhejiang. Some as long as one or two kilometers and even five or six kilometers, such as the Shaoxing Ruan She has a "hundred holes of the Government pond" fiber road bridge, built in the Qing dynasty during the reign of the Tongzhi period, the bridge is more than 380 meters long, 115 spans, the bridge deck with three pieces of stone splicing, the bottom of the flat to the water. "Curved bridge", a unique bridge in the garden, also known as the garden bridge. Bridge and path, corridor are for garden visitors to enjoy the scenery of the channel. "Scenery is wonderful in the curve", so the bridge in the garden is made of folded corners, such as the nine curved bridge to form a swing back and forth, looking left and right of the folded line, to extend the scenic route, expand the effect of landscape picture. Curved bridge is generally composed of slate, railings, slate slightly above the water, railings low, resulting in the water and the water seems to be divided into non-divided, the space seems to be separated from non-separated, especially the meaning of the meaning of endless. (1) the use of arc arch form, changed our country big stone bridge is mostly semi-circular arch tradition. Most of China's ancient stone bridge arch semi-circular, this form is more beautiful, complete, but there are two defects: one is inconvenient, semi-circular bridge arch for the span of a relatively small bridge is more appropriate, while the large span of the bridge selection of semi-circular arches, will make the vault is very high, resulting in a high bridge slope, steep, horse and carriage pedestrians across the bridge is very inconvenient. Second, the construction is unfavorable, semicircular arch stone masonry with scaffolding will be very high, increasing the danger of construction. For this reason, Li Chun and craftsmen together creatively used the arc arch form, so that the height of the stone arch is greatly reduced. Zhaozhou Bridge, the main hole net span of 37.O2 meters, while the arch height of only 7.25 meters, the ratio of arch height and span of 1:5 or so, so that the realization of a low bridge and large span of the dual purpose of the bridge transition is smooth, vehicles and pedestrians are very convenient, but also has the advantages of materials province, construction convenience. Of course, the arc-shaped arch on both ends of the bridge foundation of the corresponding increase in thrust, the need for the bridge foundation of the construction of higher requirements. (2) Adopt my shoulder. This is Li Chun on the shoulder of the arch to make significant improvements to the previous bridge construction used in the solid shoulder arch to my shoulder arch, that is, in the arch at each end of the two small arches, near the foot of the arch of the arch of the small arch of the net span of 3.8 meters, the other arch of the net span of 2.8 meters. This big arch and small arch of my shoulder arch has excellent technical performance, first of all, can increase the flood capacity, reduce the flood season due to the increase in the amount of water produced by the impact of the flood on the bridge. Ancient Kasai River flood season, the water is large, the bridge's flood capacity is a test, four small arches can share part of the flood, it is calculated that four small arches can increase the water area of about 16%, greatly reducing the impact of floods on the bridge, improve the safety of the bridge. Secondly, my shoulder arch can save a lot of soil and stone materials than the solid shoulder arch, reduce the self-weight of the bridge body, according to the calculation, four small arches can save 26 cubic meters of stone, reduce their own weight of 700 tons, so as to reduce the bridge body on the abutment and the bridge foundation of the vertical pressure and the horizontal thrust, increase the solidity of the bridge. Thirdly, it increases the beauty of modeling, the four small arches are balanced and symmetrical, the big arch and the small arch form a complete picture, which looks more light and beautiful, reflecting the complete unity of architecture and art. Fourthly, in line with the theory of structural mechanics, my shoulder arch structure makes the bridge in a favorable condition when bearing, which can reduce the deformation of the main arch ring and improve the bearing capacity and stability of the bridge. (3) Single hole. China's ancient traditional construction methods, generally longer bridges are often used in the form of multi-hole, so that the span of each hole is small, gentle slope, easy to build. But the porous bridge also has shortcomings, such as piers, not only is not conducive to navigation, but also impede the discharge of floodwaters; piers for a long time by the impact of water, erosion, easy to collapse over time. Therefore, Li Chun in the design of the bridge, took the form of a single hole long span, the center of the river does not set up piers, so that the stone arch span up to 37 meters long. This is an unprecedented innovation in the history of China's bridges.