Scientific and technological archaeology unveils the mystery of the Ayutthaya bricks in Fengtai Freight Yard
Studies have determined that ancient bricks were produced in Linqing, Shandong, and some ming dynasty city brick inscriptions can be seen
The dismantled Ayutthaya bricks have been centrally kept
The research group conducted elemental detection of Ayutthaya bricks Courtesy photo/Ancient Chinese green brick research team
Today is The International Day of Monuments and Sites. Beijing Youth Daily reporter recently learned from the Municipal Bureau of Cultural Relics and other departments that the "Fine Dismantling of 100,000 Old City Bricks in Fengtai Freight Yard" reported by this newspaper on June 12, 2020 has made the latest progress. Where did these old city bricks "hidden" in a freight yard in Fengtai District come from? Why did you end up in Fengtai District? What historical information is included in the brick text? In order to solve many questions, the ancient Chinese green brick research team of the Beijing Institute of Ancient Architecture (Tianjin University) exerted its own scientific research advantages and recently completed a special study on the city bricks of Fengtai Freight Yard.
Why "Big City Bricks"
"Rafting" to Fengtai District?
Fengtai Railway Station is located in the west of the southern section of the West Third Ring Road, located in the southwest suburbs outside the capital in the Ming and Qing dynasties, why did a large number of city bricks appear near the station? This also starts with the existence of the walls of Beijing. It is understood that the demolition of the walls of the outer and inner cities was decided in March 1959, which laid the groundwork for the flow of city bricks to Fengtai District.
When the Beiqing Daily reporter visited the Fengtai freight yard in early 2017, he listened to the local elderly recall that in the 1960s, he often saw engineering soldiers driving trucks, continuously transporting Ayutthaya bricks to Liujia Village, in addition to building warehouses, villagers also used bricks to build houses.
With the support of the Municipal Garden Ancient Construction Engineering Co., Ltd., the research team of ancient Chinese green bricks of the Beijing Institute of Ancient Architecture (Tianjin University) investigated the origin of these city bricks. According to the team leader Professor Zhang Long, on July 1, 1965, the Beijing subway officially started construction. In order to facilitate construction and reduce costs, part of the city wall was demolished to build a subway. The third-class material department of the North China Metro Engineering Bureau built a warehouse on the south side of the Fengtai Railway Station to store subway construction materials, and some of the building materials used to repair the warehouse were the city bricks that were dismantled during the repair of the subway. In 1966, the construction of the warehouse was completed and became a direct warehouse for the railway soldiers. Later, the ownership of the warehouse was transferred several times, and finally belonged to the Material Company of Beijing Urban Construction Group Corporation.
515 text bricks
It is produced thousands of miles away from Jurong County
On the city bricks in the no. 1 warehouse exploration pit, the reporter of the Beiqing Daily once saw the stamp of the words "Jurong County kiln maker Li □", and the inscription after the Li character was blurred and illegible. According to Zhang Fengliang, they found nearly 20 text bricks during the dismantling process.
Professor Zhang Long explained that the text on the city bricks is called inscriptions or sections, which is the product of the ancient "Wule Gong Name" real-name responsibility system, and the city brick inscriptions contain information such as the production date, the brick burning official kiln, the kiln household, and the craftsman. If there is a quality problem with the city bricks, it can be convenient to pursue responsibility. The research team found that the text of two Ming Dynasty city bricks was relatively clear and complete.
The first brick inscription reads "Made by Xiàn of the Fourteenth Year of Jiajing". The inscription begins with an era number, showing that this brick was produced in the fourteenth year of Ming Jiajing (1535 AD), of which the word "spring" is characteristic of the Brick script of the Jiajing Dynasty. According to relevant records, after the Jiajing Dynasty of the Ming Dynasty, most of the city bricks in Beijing were fired in Linqing, Shandong. Comparing the Jiajing Dynasty Linqing brick inscriptions that have been found, it is speculated that this brick is also produced in Linqing, Shandong.
The inscription on the second brick reads "Zhengde Ding Nian Jurong County Kiln Craftsman Dong Gui Si Zhao". This brick text begins with the name of the dynasty and is produced in the year of Ming Zhengde Ding Di (Zhengde II, 1507 AD), which has a history of 515 years. And the Beiqing Daily reporter saw the text brick, and the place of origin is the same as Jurong County. This inscription proves that in the early days of the construction of the city of Beijing, there was indeed a situation of transporting city bricks from Jiangnan. The current Jurong City is a county-level city under the jurisdiction of Jiangsu Province, more than 1,000 kilometers away from Beijing.
Then the problem also arises, most of the city bricks in Fengtai Freight Yard do not have stamps, and how to determine their origin?
Linqing, Shandong
It is the main production area of this batch of city bricks
The research team of ancient Chinese green bricks of Beijing Institute of Ancient Architecture (Tianjin University) has explored the detection method of ancient Chinese green brick materials in recent years, laying a foundation for the traceability of urban bricks. By detecting the elemental composition of city bricks and comparing the elemental composition of city bricks in other production areas, the team inferred the origin of city bricks.
The research group intercepted some of the city bricks to obtain fresh sections, and used a "handheld fluorescence spectroscopy analyzer" to conduct laboratory tests on the city brick sections, and the results showed that the reference range of four main element content was 46% to 53%, aluminum was 11% to 14%, iron was between 9% and 13%, and calcium was between 13% and 19%.
Combined with the urban brick elements detected by the research group in the early stage, compared with the city bricks clearly produced in Linqing, Shandong, the main element ratio of most of the city bricks in Fengtai Freight Yard is the closest to it. It can be inferred from this that most of the city bricks tested are produced in Linqing, Shandong. Linqing City is now a county-level city under the jurisdiction of Shandong Province, more than 400 kilometers away from Beijing.
Professor Zhang Long pointed out that the above test results further show that the royal brick production area in the Ming and Qing dynasties was Linqing in Shandong Province at the confluence of the Beijing-Hangzhou Grand Canal and the Zhangwei River, which confirmed the fact that Linqing became the brick firing center of Beijing after the middle of the Ming Dynasty. In Linqing, there are still such folk songs: "The bricks of Linqing, the city of Beijing, and the Forbidden City have Linqing." ”
Experiments prove it
This batch of city bricks is of high quality
After grasping the historical origin of the city bricks, in order to verify the quality of these city bricks, the research group tested the physical and mechanical indicators such as their bulk density, rebound value (hardness), and compressive strength.
To detect the rebound value of the city bricks, the research group adopts a special rebound instrument for measuring bricks. After completing the rebound value detection, the research group used an ordinary cutting machine and a metallographic cutting machine to cut a cube sample of 4 cm × 4 cm × 4 cm in each green brick sample, placed it in an oven to dry, measured its size and weight with a vernier caliper and an electronic balance, and then used a universal testing machine to test its compressive strength. Through the detection of the data, it can be found that the density of this batch of city bricks is larger, the hardness is higher, and the physical and mechanical properties are excellent.
In the microscopic photos of the existing city bricks and Linqing bricks in Fengtai Freight Yard, it can be seen that both have the characteristics of dense microscopic morphology, uniformity, small porosity, and round pore shape, and good physical properties. Professor Zhang Long believes that the above results prove that the beijing city bricks produced in Linqing, Shandong Province, are of high quality and are selected after strict selection and verification, and are worthy of the reputation of Linqing bricks as "knocking sound, breaking without holes, hard and solid, not alkali and no erosion".
"I hope that the public will actively provide clues about Beijing city bricks"
Interlocutors: Li Liangqi, director of the Cultural Relics Protection Department (Revolutionary Cultural Relics Division) of the Beijing Municipal Bureau of Cultural Relics
It lasted five years, from discovering city bricks, protecting city bricks, to studying city bricks. The protection action began with the cultural security volunteers, the government departments led the decision-making, gave full play to the scientific research strength of the universities, so that the cultural protection action was steadily deepened, and the cultural heritage was protected while the enthusiasm of the cultural security volunteers was protected to the greatest extent. In this process, the public, the media, the government, and universities form a benign and orderly interaction. On the eve of the International Day of Monuments and Sites on April 18, a reporter from the Beiqing Daily interviewed Li Liangqi, director of the Cultural Relics Protection Department (Revolutionary Cultural Relics Division) of the Beijing Municipal Bureau of Cultural Relics.
Beiqing Daily: The Beijing Municipal Bureau of Cultural Relics lasted five years to coordinate the protection and research of the city bricks of Fengtai Freight Yard. Next, how will the Municipal Bureau of Cultural Relics use this batch of city bricks?
Li Liangqi: According to the previous plan, we have completed the protection and research of this batch of urban bricks. With reference to expert opinions, it is more likely that this batch of city bricks came from the Beijing city wall or city tower, and will still be used in the maintenance and protection projects of the Ming and Qing Dynasties Beijing city wall in the future, but such projects are not common, and the city bricks can only be properly preserved first in case of emergency.
Beiqing Daily: In addition to the batch of city bricks in fengtai freight yard, has the municipal cultural relics bureau found other large-scale city bricks?
Li Liangqi: As early as 1996, when Beijing built the Ming City Wall Relics Park, the Municipal Bureau of Cultural Relics carried out the activity of "Loving Beijing City and Donating City Wall Bricks", and received more than 400,000 city bricks donated from all walks of life. After that, in addition to the discovery of city bricks in the Fengtai freight yard, the Shahe Base of the State Earthquake Administration and the Beijing Metro Locomotive Factory have successively discovered considerable scale of city bricks, and experts have been organized to go to the scene to investigate, and the Municipal Bureau of Cultural Relics will pay close attention to the infrastructure projects of the unit where the city bricks are located, and carry out protection and research in a timely manner.
It is worth mentioning that we found a larger number of text bricks at the Shahe base of the National Earthquake Administration, many of which are bricks outward when building buildings, which makes people clear at a glance and has considerable historical value and research value.
Beiqing Daily: If the public finds clues about city bricks, how should they deal with them?
Li Liangqi: With the continuous discovery of urban bricks, our research will continue to be carried out, and we also hope that the general public can actively provide clues about Beijing city bricks and help the research and protection of Beijing city wall city bricks. If the public finds city bricks, they can provide clues to the cultural relics department of the district where the discovery is located. For example, there is a citizen in Tongzhou District who has preserved hundreds of big city bricks and hopes to donate them to the cultural relics department free of charge, so we arrange manpower to collect them in his home, and these city bricks are now preserved with the Fengtai city bricks. Last year, the cultural relics department of Haidian District found more than 200 city bricks, and after coordination with the Municipal Bureau of Cultural Relics, these city bricks were handed over to Miyun District for the repair of the Great Wall.
How were the 100,000 "big city bricks" discovered?
Beijing Urban Construction Group Corporation Materials Company (now Beijing Urban Construction New Materials Co., Ltd.), located in Liujia Village, south of Fengtai Railway Station, originally more than 300 acres of yards, distributed more than 20 large and small warehouses. In 2017, Fan Jiping, a member of the Beijing Municipal Association for the Protection of Cultural Relics, found countless large green bricks in the platform gang of Warehouse No. 1, 2, 3, 4, 17 and 18, as well as on the walls of some courtyards, the volume of which was basically consistent with the Ming and Qing Dynasty Beijing city wall bricks recorded in the data. On September 27 of the same year, the then "Legal Evening News" reported on the matter under the title of "Old Beijing City Wall Bricks Returned to the Hidden Fengtai Freight Yard."
The above report attracted the attention of the municipal leaders, who instructed the Beijing Municipal Bureau of Cultural Relics to take protective measures. At the beginning of 2020, with the implementation of the reconstruction and expansion project of Fengtai Railway Station, the project unit plans to demolish all the warehouses, and the Ayutthaya bricks are once again facing "relocation". The Beijing Municipal Bureau of Cultural Relics took this opportunity to organize and guide the investigation and research of relevant units in a timely manner, and the heavy responsibility of dismantling and storing the old city bricks was handed over to Beijing Garden Ancient Construction Engineering Co., Ltd. to complete.
Through trial demolition and digging pits, Zhang Fengliang, the person in charge of construction and chief engineer of Beijing Landscape Architecture And Ancient Construction Engineering Co., Ltd., judged that the number of dacheng bricks in the yard of the material company exceeded 100,000 pieces, including whole bricks, half bricks, and more than 1/3 of the remaining bricks. In addition, there are two specifications of thin and thick bricks in the courtyard: thin bricks are 48 cm long, 24 cm wide and 10 cm thick; thick bricks are 48 cm long, 24 cm wide, 13 cm thick, and weigh nearly 25 kg. In order to avoid damage to the city bricks, the construction adopts "fine disassembly", and workers can only use manual tools such as hammers and flat hammers.
On June 12, 2020, Beijing Youth Daily further tracked the above incidents under the title of "Fine dismantling of 100,000 old city bricks in a freight yard in Fengtai". It is understood that later affected by the epidemic factors, the brick demolition project lasted until October 2021 and was finally completed, and more than 100,000 large city bricks were packaged according to specifications and completeness, and have now been centrally stored.
What is "Big City Brick"? In the process of protecting city bricks, the staff of the Municipal Garden Ancient Construction Engineering Co., Ltd. mostly called them "big city bricks". According to the Beiqing Daily reporter, such a common name is related to the large volume of Beijing city wall bricks. In the Ming and Qing dynasties of Beijing, the length of the city wall bricks was basically 48 centimeters, and in the altar temple buildings in Beijing, even 52 centimeters of green bricks were found, and their volume was significantly larger than the city wall bricks and the Great Wall city bricks around Beijing.
Source: Beijing Youth Daily