Notre Dame de Paris under restoration (see World Heritage)
May 18 is "World Museum Day".
Around the world, many museums are built on monuments and sites; the information and functions carried by more monuments have actually surpassed the museums.
A year after the fire struck Notre Dame, Chinese cultural heritage workers have not forgotten the legend and ups and downs of this World Heritage experience. Through close-up on-site observation, I realized the efforts made by French counterparts in protection and reinforcement, monitoring and analysis, and file arrangement, and also sought experience from it.
Notre Dame de Paris is a world-renowned cultural heritage, a symbol of Paris and a symbol of France. It was included in the World Heritage List by UNESCO in 1991.
Notre Dame de Paris is an outstanding representative of early Gothic architecture in Europe. It is an epic building. Its carving art and painting art, as well as a large number of art treasures in the hall, are of high value and enjoy a high reputation in the cultural heritage industry . The integration of Notre Dame de Paris with the lives of locals is an important spiritual sustenance for Parisians and French. Every year, nearly 13 million tourists visit here.
Badly damaged
covered in wounds
The fire in April 2919 severely damaged the overall structure of Notre Dame Cathedral. Almost all the wooden structures were burned, the iconic spires and some roofs collapsed. Although the main structure of the building was preserved, the stability was greatly affected. The spire of Notre Dame de Paris is more than 90 meters high and is made of a large amount of oak and lead. It is known as the finishing touch of Notre Dame de Paris and is the closest place to God in the minds of believers. Although the old oak is not flammable, it is still hard to escape the fire. Two-thirds of the roof collapses and the building ’s mechanical structure changes dramatically, so the superstructure is very unstable and the wall is at risk of collapse. After the vault burned, the flying buttress lost its support, and there was also a risk of collapse. After high-temperature combustion and fire-fighting of stone materials, the stability and strength will change to varying degrees, and a comprehensive evaluation has not yet been carried out.
The melting and sticking scaffolding poses a serious threat to the vault. Before the fire, Notre Dame de Paris was undergoing local repairs, including the repair of the spire. In order to carry out repairs, hundreds of tons of scaffolds were installed on the roof, consisting of about 50,000 pipes. Due to the fierce fire, many metal pipes deformed and melted together. The scaffolding itself is in danger of collapsing, and the building itself is very fragile, and the scaffolding is connected to the vaults. Therefore, the scaffolding poses a serious threat to the safety of several vaults. How to dismantle scaffolding without causing other problems has become an urgent task, and is also one of the most complicated projects at the moment.
Because you can only enter the vault after removing the scaffolding, if you want to remove the old scaffolding, you need to build a new scaffolding, so that the workers can go up and saw the old scaffolding before they can be hung down one by one. At present, new scaffolding is also being built one after another. In December 2019, a 75-meter-high crane has been erected by the Seine, which will be used to remove the scaffold. This project will last for several months. "Once the scaffolding is removed, we can assess the status of Notre Dame and the number of stones that need to be replaced," said the dean of Notre Dame.
Repair and reconstruction
Hard exploration
The day after the fire, French President Macron appointed the former commander-in-chief of the army as the chief of the reconstruction project. The restoration and reconstruction work is highly valued by the French government and has also received widespread attention from the international community.
The spire is the focus of this restoration project, which once triggered brainstorms in the architectural and heritage circles of various countries. The restoration is different from the initial construction, and it is necessary to retain the original structure, materials and style to the greatest extent, and to prevent secondary collapse during construction. Therefore, there will be some unexpected difficulties in the road to recovery after the disaster. To formulate a scientific and reasonable restoration and reconstruction plan, it is necessary to systematically study the construction process and construction mechanism of Notre Dame de Paris, as well as a comprehensive evaluation of the post-disaster building mechanics structure and material damage. It is also necessary to fully learn the fire lessons and strengthen security The scientific nature of fire protection design.
Comprehensive research is an important foundation for the design of restoration and reconstruction plans. Scientific research institutions such as the French National Scientific Research Center, the French Institute for Preventive Archaeology, the French Historical Monument Research Laboratory, and the French Museum Research and Restoration Center have formed a multidisciplinary research team. In the French National Science Research Center alone, more than 100 researchers in 25 laboratories participated in the study, mainly from 7 aspects of masonry structure, wooden structure, metal structure, glass, acoustics, digital data collection and anthropology Research. The series of studies carried out this time will trace the roots, uncover the mystery of Notre Dame de Paris, and restore the reconstruction and restoration process, such as what work was done in different periods, what major changes have been experienced, and where the building materials come from, What are the characteristics, what impact did the fire suppression process have on the building, etc. The fire is certainly a disaster, but it is a good thing to use this opportunity to conduct a comprehensive and systematic study of the structure of Notre Dame and its archives. It can provide an important basis for this restoration and reconstruction, and it can also lay a foundation for future protection. Good foundation.
For safety reasons, thousands of square meters of protective nets with a height of about 10 meters were installed inside and outside the church to protect the safety of pedestrians and construction workers on site, and some dangerous areas were specially protected. The main arch structure of Notre Dame is more complicated and becomes very fragile after the fire. In order to conduct a complete diagnosis, manual detection and automatic monitoring have been carried out at the same time. Technicians regularly enter it through the rope to check the safety of the arch. The debris removal work is mainly done with the help of robots. Fragile or damaged sculptures are removed, and other sculptures are protected in situ. In order to reduce the risk of the flying buttresses collapsing, several months of reinforcement work has been carried out, that is, placing wooden supports underneath to support them, 28 flying buttresses have been reinforced, which is an important step before the restoration work officially begins. After the fire, there were a lot of wood and stone debris in the nave and ear hall. The researchers used 3D images to make a list of the debris of the nave and ear hall to determine the exact location in the building before they collapsed. The nature and structure of the stone are evaluated and analyzed to determine whether it can continue to be used. Their research work has provided valuable insights for accurately judging the condition of Notre Dame and determining the degree of repair work required.
When it comes to the restoration of Notre Dame de Paris, one important person has to be mentioned. He is Andrew J. Tallon, known as a scholar of French Gothic art and architecture innovation. As early as 2015, he used 3D technology to collect a lot of information on Notre Dame de Paris and discovered some important clues in the construction and renovation of Notre Dame that year, thus creating a detailed digital archive. This precious archive may provide an important basis for the restoration and reconstruction of Notre Dame Cathedral. The important role of digital technology in the protection and restoration of cultural heritage will also be highlighted.
Deep reflection
Learn a lesson
Although the cause of the Notre Dame fire has not been announced, the mainstream view is that it was caused by omissions in the repair project. This fire once again sounded the alarm for the world. There should be no negligence in the safety of cultural relics, a little negligence, and the consequences will be unimaginable. Among the cultural relics and buildings in various countries in the world, wooden structures account for a large proportion, the hidden fire hazards are more prominent, and the task of safety prevention is more arduous. Therefore, it is necessary to deeply learn the lessons of this fire, comprehensively strengthen the sense of responsibility, and promote the continuous upgrade of security and firefighting facilities Rehabilitation project construction personnel training and on-site safety supervision, to curb the occurrence of fire from the source.
The impact of the Notre Dame fire on the surrounding environment has also attracted great attention from researchers. Due to the good plasticity of lead, more than 300 tons of lead were used in the construction of the roof and spire of Notre Dame Cathedral. The lead melted in the fire and formed lead dust that spread to the surroundings and seriously polluted the surrounding environment. The test found that there were already excessive amounts of lead in children's blood around Notre Dame de Paris. In order to thoroughly clean up lead pollution, the Paris municipal government used high-pressure spraying to apply decontaminating surfactants and adhesives to the soil near the Notre Dame Cathedral, and the construction of Notre Dame Cathedral was temporarily suspended. This also reflects the danger of fire from another aspect, and the importance of preventing fire.
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On April 15, 2019 local time, a fire broke out at Notre Dame de Paris, which once again sounded the alarm for the safety of cultural relics. On the evening of April 16, 2019, the State Administration of Cultural Heritage of China notified six cultural relic fire accidents since 2019. The report requires all localities to implement safety responsibilities, strengthen fire-fighting measures, and in the near future will conduct a test and evaluation of cultural relics and fire-fighting facilities and equipment, and replace and upgrade old and damaged facilities and equipment to ensure the effectiveness of use.
The notification clearly states that fire accidents in cultural relics and museum units in various places shall be reported in accordance with the prescribed procedures and time limits, and shall not be overlooked according to the cause of the accident, failure to be handled by responsible personnel, rectification measures not implemented, and lessons learned. Without absorbing the requirements of not letting go, investigate and deal with fire accidents in accordance with laws and regulations. Anyone who conceals, falsely reports, or lately reports a fire accident, or has committed dereliction of duty in the work of cultural relics and fire safety shall be held accountable in accordance with law and discipline.