Bridge pier and abutment

Piers and abutments are collectively referred to as buildings supporting the superstructure of bridges. Abutment is located at both ends of the bridge and connected with embankment, which has the function of retaining soil; The pier is located between two abutments. Pier and bridge foundation are collectively called bridge substructure. Before the Zhou Dynasty in China, stones were piled in the river for wading. In the Qin Dynasty, a horizontal bridge with stone pillars was erected in Weishui, Xianyang. It is "6 feet wide, 380 steps from north to south, 68 rooms, 750 columns and 122 beams" (three auxiliary Huang Tu). In the Tang Dynasty, Chang 'an Middle Bridge "rushed into the water at the age of 20" ... Li Dezhao's creation was full of accumulated stones, and the water potential was in front of it, so there was no drift loss (China Stone Bridge). This type of pier has been used to this day. In modern times, piers and abutments developed from masonry to concrete pouring. At the same time, with the development of bridge technology, piers and abutments of some bridges have become an integral part of bridge superstructure. For example, the superstructure of T-shaped rigid frame bridge and inclined leg rigid frame bridge is integrated with the upper part of pier. The anchorage part of the anchor cable of suspension bridge is generally combined with the abutment; The balance part of the open bridge is often arranged in the pier body; The pylon of a cable-stayed bridge usually includes piers on the foundation. In terms of pier and abutment engineering, China has made creative achievements in ancient times. For example, Bahe Bridge in Chang 'an in Han Dynasty adopted tenon-mortise structure and made a flexible stone pier with several overlapping stone drums. In the Song Dynasty, Luoyang Bridge in Quanzhou suspended huge stones to build stone piers, and the stone weighed 10 tons, which was the earliest example of pier construction by floating crane on water. In modern times, various types of concrete piers and precast piers and abutments gradually developed to mechanized assembly construction. With the improvement of construction equipment and technology, pier construction in deep water, pier construction in middle and high canyons, and pier construction with complex spatial structure are developing continuously. Most medium-span bridges at home and abroad use bent pile-column piers with convenient construction and less masonry. The Pontchartrain Lake Bridge in Louisiana, USA, is about 39 kilometers long, with a total of 1.526 basic bridge spans of 25.6 meters, of which 1.500 double-pile piers (piles with a diameter of1.64m are connected in series 1.2 prestressed steel beams) are located in/kloc. Pier is composed of cap (top cap, pier cap) and pier body. The pier cap is a part of the pier, which supports the bearing or arch foot of the bridge. Its function is to transfer the load of the bridge superstructure to the pier, and to reinforce and protect the top of the pier. Piles of pile-column piers are connected into a whole through caps. Pier body is the main load-bearing structure of pier, and its function is to transfer the load of bridge superstructure to bridge foundation and foundation. Solid pier, also known as gravity pier, relies on its own weight to maintain stability. Its integrity and durability are very good. The pier body of a solid pier is usually made of stone or concrete with high compressive strength. When the pier body is large, flaky can be mixed into the concrete which does not exceed 25% of the pier body volume, so as to save cement. Solid piers can also be built on site with prefabricated blocks, and each block is prestressed in series with high-strength steel wire bundles. When laying, the blocks should be staggered. The solid pier built in this way is also called assembled pier. Thin-walled pier is a solid thin-walled pier or a hollow thin-walled pier made of reinforced concrete. Solid thin-walled pier is suitable for medium and small span bridges. Hollow thin-walled piers are mostly used for long-span bridges and high pier bridges. Column pier is a pier made of single column or double column and multi-column by pouring concrete on the foundation. In China, two large diameter bored piles are usually used as the foundation, and columns are built on them to make a double-column pier, and a cross beam is set between the two columns to increase the stiffness. In addition, single pier is also commonly used. Pile-row piers are piers composed of single-row piles or double-row piles. The number of piles in a row is generally equal to the number of main beams in the superstructure. The cap beam connecting the top of the pile can be made of concrete. This kind of pier is usually called flexible pier because of its small pile size. According to the design of flexible structure, the distribution of horizontal force on each pier along the longitudinal axis of the bridge can be considered. Frame pier The piers composed of two or more frames are mostly made of reinforced concrete. Frame pier is light and beautiful, but it is not suitable for building in rivers with drift or ice. Abutment consists of cap (top cap, table cap) and abutment body. The platform has two parts: the front wall and the side wall (Hebei wall). The front wall is the main body of the abutment, which transfers the load and earth pressure of the superstructure to the foundation. The side wall is located behind the front wall, which mainly supports the earthwork of the dike body and can increase the stability of the front wall. Both the front wall and the side wall can be built of stone or concrete. When the superstructure is an arch system, in addition to the abutment cap where the bridge deck meets the front wall, an arch bearing should be set at the abutment supporting the arch foot. Expansion joints shall be reserved between the breast wall connected with the bearing platform and the end of the bridge deck system. Gravity abutment relies on its own weight to maintain the stability and rigidity of abutment, which is suitable for stone masonry and requires good foundation soil. The plane shapes of gravity abutment are U-shaped, T-shaped and mountain-shaped. The U-shape has good integrity and convenient construction, but the abutment back is easy to accumulate water, so blind ditch drainage should be set at the filling place of abutment back to avoid frost heaving of soil. On the soil foundation, joints should be set at the junction of wing wall and front wall to separate them from each other to avoid uneven settlement and damage. The abutment embedded in the conical slope protection of embankment only exposes the part above the abutment cap to support the superstructure of the bridge. Because it is buried in the soil, the earth pressure on this abutment is very small and the stability is good. The cone-shaped slope protection often extends into the river, encroaches on the drainage area and is easily washed away by the current, so we must attach great importance to the protection of slope protection; In the design, if the slope protection is damaged by erosion, the stability and strength of abutment should be checked. Thin-walled abutment abutment is made of L-shaped thin-walled wall. This abutment has a front wall and buttresses, the front wall is the main load-bearing part, and the buttresses are arranged on the back of the front wall and supported on the bottom plate of the wall. If the buttress has a main road, its function is to increase the rigidity of the front wall. The table cap is placed on the top of the front wall. The filler above the bottom plate helps to keep the abutment stable. Wooden piers and abutments are mainly used for wooden bridges. This kind of pier is only used in some forest areas where materials are easy to obtain, and other types of bridges also use wooden piers or cribs as temporary supports during maintenance and emergency rescue.

Approaching the beacon tower in Tuzitor, I am afraid that I will walk less, see less and listen less in Xinjiang. This kind of feeling has never been encountered in other areas I have been to before.

It is out of this feeling that I approached the beacon tower of Tuzi Thor.

Beacon tower is also called beacon tower, commonly known as beacon tower, smoke pier and trestle. The high platform used to light fireworks and deliver important news in ancient times is an important military defense facility in ancient times, which was built to prevent the enemy from invading. In case of enemy situation, give cigarettes during the day, light them at night, and receive messages from the platform. It is the oldest but effective way to transmit information.

Tuztor beacon tower is located near the west exit of Xinhe county, 30 kilometers away from the county. Belongs to the remains of the Tang Dynasty.

Relevant information record: the current height is about 1 1 m. Its bottom is compacted and its top is made of adobe. The plane is square and the cross section is trapezoidal. Base: East-west15.2m, north-south1.8m, with an area of about179.4m. At about10m north of the beacon tower, there are many pieces of red pottery and grey pottery with scattered sand on the surface, and turtles are collected nearby.

Speaking of which, Qiuci. The so-called Qiuci is a country in the ancient western regions. The northern margin of Tarim Basin is the seat of ancient Qiuci State, where Duhu House was established in Han and Tang Dynasties. Qiuci is the third largest country among more than 50 countries in the Western Han Dynasty, with a population of 865,438+10,6900. The scope of governance includes Kuqa, Luntai, Shaya, Baicheng and Xinhe. The capital is Yancheng, which is now Kuqa. Qiuci is located in the center of the western regions and in the middle of the Silk Road.

Xinhe County was the southwest barrier of Qiuci in ancient times, distributed in more than 50 ancient sites in the county, and more than 10 sites were identified by experts as military activities and frontier defense.

It is not difficult to find out from the schematic diagram of historical sites in Xinhe County that most of these 10 military activities and frontier defense sites are located in the southwest and northwest of Xinhe County. Around these sites, there are its dry city (the location of Khufu in the Western Regions during Ban Chao's reign in the Eastern Han Dynasty), the ancient city of Yuqikate (the bronze seal of Li Chong unearthed in the Western Regions, "Han Gui Yi Qiang Long Seal") and the ancient city of Tongguzi Brazil (Qiuci City).

Tuztor beacon tower is one of many sites in 10.

Visually, the beacon tower is less than 5 meters high, which is quite different from the relevant data. My friend who brought me told me that it was my honor to see this. She said that every time she came, she saw a different height, and she was much shorter every time.

Walking around the beacon tower, it collapsed badly, and the structure at the bottom could not be seen at all. It was all buried by the collapsed adobe, which had turned into yellow mud. There is a cave in the middle of the beacon tower near the north side. Around the cave, pieces of adobe are clearly visible.

On the east side of the bottom, there is also a cave, which has been buried by half of the soil. Looking inside, there are discarded mineral water bottles and cigarette butts in the cave. It seems that earlier, people could go in to rest in this cave, but now if they want to enter the cave, they have to crawl forward.

In the Tang Dynasty, Du You made a detailed record of the beacon tower at that time in the "Tongdian Rejection Law": "The beacon tower should be disposed of in high mountains, and it should be placed in a secluded place without mountains. To build a sheep and horse market, you can compete at will, often on the basis of three to five. This platform is five feet high, two feet wide at the bottom and one foot wide at the top. Round. Build a round house on it. The roof is ten feet six feet wide and jumps three feet at the same time, with the board as the bottom. Upper and lower floors. There are three stoves on the house and three under the stage, decorated with lime. Re-set three firewood cages and three flowing fire ropes. On the edge of the platform, use a knee ladder to take and put it. There is a thief hole and a fire extinguisher on the wall of the house. Set a flag, drum, crossbows, riprap, stow-wood, water-stop urn, dry food, hemp, fire drill, rocket, wormwood, wolf dung and cow dung. Raise the fire safely once every morning and evening, twice when you hear the alarm, and three times when you see the smoke. When you see a thief burning a firewood cage, if the fire doesn't come every morning and evening, the bonfire will be caught by the thief. There are six people in a beacon: five people are beacons, and they pay more time, depending on the movement. One person is a beacon, knowing documents, symbols and transfer. "

From this passage, we learned the face and operation mode of the beacon tower at that time.

My friend asked me to climb to the top of the beacon tower. I hesitated and climbed up against my will. It is against our will, on the one hand, because it is such an ancient relic that it is really rare. We shouldn't step on its thin body again. On the other hand, we can't resist the desire to climb the beacon tower. "Mountain is the peak" and "other mountains are dwarfed under the sky. S ",what's more, there is no constraint. ) Of course, the climbing passage is not the passage of the past, but the traces of people who have been here today.

Climbing to the foot of the mountain, you can see it everywhere, and the Gobi Desert stretches unscrupulously, with no end in sight. Black is saline-alkali land, and white is sandy land. Red willows or camel grass are scattered among them, creating a little green and giving the earth a little sign of life.

I wonder/kloc-what happened to the soldiers who stood on the beacon tower more than 0/000 years ago. They may be dignified, lonely, afraid, hungry, or killed by random arrows overnight. I dare not make any more assumptions.

It was near dusk when I left Tuztor beacon tower. It is cloudy all day. At this time, the sun seems to be blocked impatiently. With its last strength, it tore the clouds and violently shone the last strong light before falling on the horizon. The cloud is not to be outdone. Before the sun appeared, it wrapped the sun tightly.

In this context, looking back at the Tuztor beacon tower standing between the Gobi Desert, it seems dignified and lonely.

Shengqiao Yandun Wharf starts from Shengqiao Town, Lujiang County, goes west along provincial highway 3 16, then turns south, and then comes to Qili Village. In the wild of Qili village, what local residents call "smoke dome" stands here. Although in the local legend, Yandun was once a beacon tower used by Cao Jun during the Three Kingdoms period, it has never been concerned. It was not until June, 20 1 1 that a grave robbery case that caused a sensation in the whole province slightly uncovered the thousand-year history hidden under this loess ridge.

Local legend: it is Cao Cao's beacon tower.

The smoke dome is not magnificent, but a platform with a height of more than ten meters, covering an area of one mu, with a flat top and overgrown weeds. It seems to be a mound randomly piled by nearby farmers. However, according to local legend, it was an ancient beacon tower during the Three Kingdoms period. You must go to the top of the mountain to have a look. Climb to the top along the side path and you can see far away. Under the blue sky and white clouds, you can see the surrounding fields and villages.

According to local residents, during the Three Kingdoms period, Cao Cao led 830,000 troops south to the Yangtze River and passed by the Lujiang River. He saw the white lake area and thought it was suitable for garrison, so he commanded the soldiers to construct and prepared to raise horses and train soldiers in the lake. It is said that the smoke dome in Sheng Qiao was built at that time. But one day, when the soldiers were building a building, a magpie came, holding "God's will". At that time, soldiers used the bronze drum as the number, and when the drum rang, they called it a day to eat. When this magpie flew to the bronze drum, the branch in its mouth just fell off and hit the bronze drum. The soldiers heard the drums and left the construction site one after another. While they were eating, it began to rain cats and dogs, and the place where the water had just been drained was full again. When Cao Cao saw this scene, he thought it was an apocalypse, so he had to sigh that "it is not appropriate to station troops here" and withdraw his troops. As a result, it did not become Cao Cao's training ground and racecourse, but left the legend of the ancient beacon tower.

Now, there is no water around the smoke dome, and the top of the smoke dome has been planted with crops by the villagers. The truth of history was covered by crops, weeds and loess, and it slept for thousands of years.

Tomb robbery: Uncovering the Millennium Tomb

After sleeping for thousands of years, the truth buried under the smoke dome was uncovered by a group of "uninvited guests" On June 20 1 1, a grave robbery occurred here that shocked the whole province. According to Sheng, the stationmaster of Shengqiao Town Cultural Station, a group of grave robbers who fled across provinces came here to dig in the name of burying telephone poles. This group of grave robbers was only "half a step away" from success, because just as they were about to hand over the excavated cultural relics to the buyer, there was an "infighting", and one member was furious and called the police. After receiving the report, the police smashed the gang.

The grave robbers were hateful, but they uncovered the mysterious ancient tomb under the smoke dome. The cultural relics dug up by grave robbers are Yu Pei and Yu Jun. After solving the case, the local cultural relics department once entered the stolen cave to conduct a preliminary inspection of the ancient tomb, which was initially judged as the tomb of the Warring States or the Western Han Dynasty. There are many "blanks" in the historical textual research from Warring States to Han Dynasty in China. If this ancient tomb is identified as the tomb of this period, it will be of great historical research and archaeological value. Sheng Ye Sheng also said that the coffin in the ancient tomb was made of nanmu, and they found silk and other articles in the coffin. Moreover, the coffin in the ancient tomb is a four-story structure, and there is a layer of soil outside the coffin. It is very important to preliminarily judge the identity of the tomb owner.

Expert opinion: it should be "Aegis" at the earliest.

The smoke mound turned out to be an ancient tomb? Wu Shouchun, an expert in literature and history in Lujiang County, believes that the truth of Yandun does not stop there. He said that according to years of research, Yandun was originally a "god pier" where ancestors lived together. For peace, ancestors settled on the earth. The whole village lives on a high platform made of mud to resist the attack of wild animals and floods. The remains of this high platform are called "God Pier" by later generations.

Wu Shouchun believes that in order to facilitate villagers' access, most of the Shendun are built by water. In addition, due to generations of living and renovation, Shendun soil layer is obviously layered, which can be called "cultural accumulation layer". He visited more than 200 shrines found in Lujiang County, all of which have these two characteristics.

According to these two standards, he thinks that Sheng Qiao Yandun is a magical pier. He said that although there is no water flow around the smoke pier now, it is a river in history. This statement is consistent with Cao Cao's folklore of releasing water and stationing troops. He also analyzed and studied the soil layer of Yandun, and thought it was completely in line with the characteristics of "cultural accumulation layer".

According to Wu Shouchun's point of view, Yandun was originally a god pier, and later a mausoleum was built inside. In his view, the ancients paid attention to feng shui when building tombs, and the god pier was built according to water, shaped like a mountain, which met the requirements of feng shui. It is entirely possible for dignitaries to build tombs here.

In fact, history is gone, whether it is a god pier, an ancient tomb or a beacon tower. Today, Yandun has become a scenic spot in Shengqiao Town. At present, the excavation of Yandun Tomb in Shengqiao Town has been approved by National Cultural Heritage Administration, and the truth of Yandun and its "heritage" will be revealed again in the near future.

Travel tips

Route: go on road trip, starting from Hefei, enter G42 12 Expressway from Xiaoxichong Hub, drive along G42 12 for about 55km, and get off at Lujiang/Pu Jun Exit. Then enter the provincial road S3 19, enter Lu Chao Road and reach Shengqiao Town. Starting from Shengqiao Town, take provincial highway 3 16 to the west, then turn south, and you will arrive at Qili Village where Yandun's tomb is located.

By bus, take the bus from Hefei to Sheng Qiao at Hefei Xinya Bus Station. After arriving at Shengqiao Town, take the local "Mian" bus to Qili Village.

Play: In addition to the smoke mound, there are also Longshan cultural sites, Shang and Zhou cultural sites, Jincheng Temple sites and other places in Shengqiao Town, as well as a large number of precious cultural relics scattered among the people, such as temple monuments and imperial edicts in the Ming Dynasty.

Eat: Taste local specialties, such as jiaozi and Baba.

Looking for Yandun Wharf in Ming Dynasty

On the afternoon of July 4th, Shenzhen's first outdoor one-day tour project "One-day Tour of Yantian Mountain and Sea" launched the sixth one-day tour to visit Yantian Yandun in Ming Dynasty. Zhang Yibing, an expert on local chronicles in Shenzhen and a researcher at Shenzhen Museum, led nearly 30 public readers to climb Meishajian. Through the way of "outdoor+reading", he combined the outdoor mountaineering loved by Shenzhen people with the study of local history and culture, traveled through history, searched for the remains of Yandun in the Ming Dynasty, and felt the bonfire and smoke on the land of Yantian.

In the "Xueshuba", the first book bar library in Yantian District, citizens learned the basic situation of Yandun in Shenzhen in Ming and Qing Dynasties for the first time, and understood the position and role of Yantian Yandun in the history of China's coastal defense. According to Zhang Yibing, the smoke dome is a beacon tower. The history of Yandun in Shenzhen began with the establishment of a health clinic during the Hongwu period of the Ming Dynasty. Yantian Yandun was not clearly recorded until the 14th year of Jiajing, Tongzhi County, Guangdong Province. At that time, Yantian belonged to Dapeng Shouqian household. However, in the 26th year of Wanli (1598), Volume 32 of Guangdong Dazhi, Guangdong Coastal Map, Yantian Wharf, abutment, etc. can't be found, and they should have been abandoned long ago. Later, a new pier 2 1 was built at the edge of the 7th year exhibition of Kangxi, including a pier in Yantian, a pier in Dameisha and a pier in xiaomeisha. Based on this, it is inferred that the existing smoke dome should be Yantian smoke dome, which belongs to the remains of Jiajing Dynasty in Ming Dynasty.

Then, the mass readers drove to the direction of Meishajian, climbed the steps along the hiking trail, and finally saw a stone pier after about 40 minutes. The pier is very close to the hiking trail, and the rest of the pier base is only about two meters high, surrounded by weeds and shrubs. There is no sign of adhesion between the stones on the pier foundation, and you will feel wobbly when standing on the pier foundation. According to Zhang Yibing, Yantian Yandun is very representative in Guangdong and relatively well preserved. Its discovery provides important evidence for Yantian as an ancient coastal defense fortress, which has very important historical and cultural value. At the event site, Zhang Yibing also led everyone to understand the structure, function and how to date the smoke pier.

It is reported that this year's outdoor one-day tour of "Tour of Mountains and Seas, One-day Tour of Yantian" series is divided into four series, namely, traveling with literary peers, mountain and sea inspection season, coastal life season and historical humanities season, with 10 activities as the themes, respectively, Yantian people, the remains of the smoke mound in Meishajian and the first meaning of Sanzhoutian. 20 15 every month 1 hold a series of activities of "Mountain and Sea Tour Yantian". All activities are open to the public for free registration. The general public can register through the poster of Yantian District Library, official website and "You Yantian" WeChat WeChat official account to learn about the latest activities.