Historic ancient bridge
Weishui Third Bridge, located near Xianyang Old Town, was very famous in ancient times. The third bridge, including Zhongwei, Dongwei and Xiwei, is a multi-span wooden beam-column bridge. Among them, Zhongwei Bridge was built in Qin and Zhao Haoqi during the Warring States Period, and was rebuilt and strengthened by Qin Shihuang. The bridge is about 525m long and13.8m wide, which is close to the lane width of Nanjing Yangtze River Bridge. It consists of 750 wooden columns, 67 piers and 68 spans, with an average span of 7.72 meters and a middle span of 9 meters. A top beam is added to the wooden column pile group to form a bent pier, then a big wooden beam is put on the bent, a wooden bridge surface is paved, and carved railings are set on both sides of the bridge. The middle bridge hole is high and large, and the bridge holes on both sides are low and small, showing a figure of eight, which can not only make tall ships pass smoothly, but also quickly drain the rainwater on the bridge deck and prevent rot. At both ends of the bridge, huabiao, water demon stone tablets and stone lamp posts are erected for signs and lighting. In Han Dynasty, Zhongwei Bridge was rebuilt, and East Wei Bridge and West Wei Bridge were built.
The beam bridge in Han dynasty has been quite popular. On the stone reliefs of Han tombs unearthed in Yinan, Shandong Province, there is even a design of Liang Shi Bridge engraved. During the Tang Dynasty, many famous Liang Shi Bridges appeared. According to the Six Classics of the Tang Dynasty, there are four famous Liang Shi Bridges in the world: Tianjin Bridge, Yongji Bridge, Middle Bridge and Xi Ba Bridge. Baqiao is located on the Bahe River, 20 miles northeast of Xi 'an. It is a wooden beam bridge with columns and piers. Since the bridge was built in the Han Dynasty, it has been destroyed and repaired for two thousand years. It was not until the 13th year of Daoguang in Qing Dynasty (AD 1833) that today's multi-span beam bridge was built, which lasted for 9 months. The bridge is nearly 400 meters long and has 67 holes. The net span of each hole is about 6 meters and the bridge width is about 7 meters. This pier consists of six stone pillars. The top of the six stone pillars are covered with A Liang stone, which forms the earliest light pier in the bridge history, that is, today's stone raft pier. This ancient bridge, which has been the traffic throat for thousands of years, has been transformed into a modern highway bridge today.
In the Song Dynasty, people's ability to overcome nature was improved, and the first large stone beam bridge near the bay in China-Wan 'an Bridge-Luoyang Bridge was built in Quanzhou, Fujian. The bridge is 834 meters long and 7 meters wide. There is an island in the middle of the bridge, with seven holes in the south and 4 1 hole in the north. The span of each hole is about 1 1 m. The bridge is built at the mouth of the sea, where the water flows fast and there are many local earthquakes and typhoons, so the bridge construction project is quite arduous. The next section of this book will specifically introduce this. After the completion of Luoyang Bridge, it was a sensation, with the reputation of "the first bridge in the world", which set off a "bridge-building fever" in the local area. During this period, the newly-built Shidun Bridge in Liang Shi, Fujian Province has reached a new level in length, span, weight, construction speed, construction technology, bridge type and bridge foundation, and occupies an important position in the history of bridge construction at home and abroad. Anping Bridge in Jinjiang City, Fujian Province and Hudu Bridge in Zhangzhou City are outstanding representatives. Anping Bridge, with a total length of 865,438+065,438+0 feet and 362 holes in five miles, is a rare ancient long bridge in the world and is known as "no bridge in the world is so long". The largest Liang Shi of Hudu Bridge is 23.7 meters long, 1.7 meters wide and 1.9 meters high, and weighs 207 tons. It is the heaviest Liang Shi in the world.
With the development of social productive forces, the forms of beam bridges are constantly changing. For example, in the water towns in the south of the Yangtze River in China, people often build this kind of bridge into a splayed or stepped structure with a high hole in the middle and a small hole in the side, and there are also several unique steps at the bridgehead on both sides to attract people to get on the bridge. There is also an optical fiber bridge parallel to the river along the canal from Shaoxing to Hangzhou. Some ancient bridges in Liang Shi set gates under the bridge or channels on the bridge, which made one bridge multi-purpose. According to historical records, a cantilever wooden beam bridge was built in the border area between Gansu and Xinjiang, which was called the end country in ancient times. This kind of bridge uses logs or squares stacked vertically and horizontally, picking them out from the shore or pier layer by layer and extending to the center of the valley, just like the layers of arches in ancient buildings. Locals call this kind of bridge "flying bridge", which is easy to see in areas with more wood in the south. Some bridges also have bridge houses or bridge corridors. There are colored paintings and Buddha statues in the corridor, and the bridge looks like flowers, so it is called the flower bridge. On holidays, Huaqiao has become a place for people to entertain, go to the market and catch up with temple fairs. For example, Chengyang Bridge in Sanjiang, Guangxi is a famous flower bridge that organically combines function and decoration. In addition, there are wooden support bridges and beam bridges with cantilever beams and supports.
The earliest recorded beam bridge in the history of China is the Giant Bridge, which was built in Shang Dynasty (BC 16~ 1 1 century). Zhou Wuwang cut grain, Ke Shangdu sang (now Chao Ge Town, Qi County, Hebi County, Henan Province), and Faju Bridge (now Juqiao Town, Xun County) accumulated millet to help the poor. From the Zhou Dynasty to the Qin Dynasty, many stone pillars and wooden beam bridges were built in China.
A large number of stone piers and Liang Shi Bridges were built in Song Dynasty. For more than 200 years, in Quanzhou alone, there are 1 10 bridges found in ancient books, including 10 famous bridges. For example, Anping Bridge has 362 holes, and the length of the bridge is 5 Li (2,223 meters), so it is also called Wuli Bridge (now the length of the bridge is 2 100 meters), which has maintained the record of bridge length for more than 700 years. The bridge was built in the eighth year of Shaoxing (A.D. 1 138) and the twenty-first year of Shaoxing (A.D. 1 15 1) in the Song Dynasty and lasted for 13 years.
Another example is Wan 'an Bridge in Quanzhou, commonly known as Luoyang Bridge, which has 47 holes and was built at the mouth of Luoyang River. The bridge is about 890 meters long and 3.7 meters wide. The bridge was built in the fifth year of Song Dynasty (A.D. 1053) and completed in the fourth year of Song Dynasty (A.D. 1059). Both bridges are national key cultural relics protection units.
Liang Shi is the largest of the Jiangdong Bridge in Zhangzhou, Fujian. In the first year of Song Jiaxi (A.D. 1237), it was changed from a wooden beam bridge to a stone bridge with 15 holes, each with three holes. There are five stone bridges, the largest of which, Liang Shi, is 23.7m long,1.7m wide,1.9m high and weighs 2000kN (200 tons). Such a huge Liang Shi, without heavy lifting equipment in ancient times, its excavation, transportation, installation and other work are very arduous.
In order to lengthen the bridge span, both the wooden beam and the Liang Shi adopt the method of multi-layer parallel beams, which are lifted from bottom to top layer by layer to support the simply supported beam in the middle. At that time, Liang Shi called it astringency; The wooden beam is called flying bridge or holding bridge, which is the cantilever beam bridge. There are records about wooden cantilever beams in the 4th century AD. Stone bridges overlap, not far from the eaves; This wooden bridge is 20 meters long. Yin Ping Bridge in Wenxian County, Gansu Province, which was rebuilt in Qing Dynasty, is a single-hole wooden cantilever bridge with a span of more than 60 meters.
There are generally bridge houses or bridge corridors on wooden beam bridges, and the wind and rain bridge of Dong nationality is one of them. Chengyang Yongji Bridge in Sanjiang Dong Autonomous County, Guangxi is a wooden cantilever bridge house with 4 holes and 5 piers, with a total length of 644 meters. Built in 19 16. There are bridge pavilions on five piers, which are connected by bridge corridors. The bridge pavilion plays the role of gravity balance and organically combines decoration and function.