The sunlight that crossed the East Mountain, swept across the water of the Yihe River, and shone into the Longmen Grottoes of the West Mountain.
In the safe construction area in front of the Lusena Buddha in Fengxian Temple, several workers stood vertically on the scaffolding, dismantling and passing the wooden steel pipes with their bare hands.
With the dismantling of the scaffolding and green nets that shrouded the alcove, the Buddha's true appearance has gradually emerged.
"Dalushena Statue Niche" is the largest cliff-like shrine excavated in Longmen Grottoes, and it is also the most representative work in Longmen Tang Dynasty sculpture art.
The Lushena Buddha, with its "rare appearance, like the moon and the sun", has conquered tourists at home and abroad.
However, for thousands of years, water seepage and endangered rock mass have been the main diseases threatening the safety of cultural relics here.
In December last year, Fengxian Temple's water seepage control and dangerous rock mass reinforcement and protection projects began. The project range from the bottom of Fengxian Temple to the upper mountain is nearly 50 meters high and about 70 meters wide.
On July 19 this year, the project passed the preliminary completion acceptance organized by the Luoyang Municipal Bureau of Cultural Relics, nearly two months ahead of the original plan.
During the 228 days, all those who had been close to the 17.14-meter-high and 4-meter-high Buddha along the scaffolding and reached the head of the Buddha will be shocked by the face-to-face perspective of the ancient craftsman, and feel that this is a once-in-50-year encounter. It is a rare opportunity for scholars and artists invited by the Longmen Grottoes Research Institute to sit on the shelf and have a silent dialogue with the Buddha.
Three major diseases
In January 2000, the Longmen Grottoes were included in the World Heritage List.
Evaluation meeting of the World Heritage Committee: The grottoes and Buddhist shrines in the Longmen area show the largest and most outstanding plastic arts from the late Northern Wei Dynasty to the Tang Dynasty (493-907) in China.
These works of art detailing Buddhist religious themes represent the peak of Chinese stone carving art.
Shi Jiazhen, director of the Longmen Grottoes Research Institute, said that, as a royal project, the Longmen Grottoes have top-notch design, top-notch teams, and the most suitable limestone for fine carving. As well as the formation and structure of the Xishan Mountain, the dangerous rock mass and water seepage have always been the main diseases that threaten the safety of the cultural relics of Longmen Grottoes.
Ma Chaolong, director of the Grotto Protection Research Center of the Longmen Grottoes Research Institute, said that the seepage water caused the dissolution of the rock mass, and the dissolved matter re-formed calcium carbonate deposits on the surface of the cave carvings. will be affected."
The lithology of Longmen West Mountain has a large lateral change, which is prone to cracks. In addition, in ancient times, when excavating grottoes, it was necessary to cut the mountain into a wall, which destroyed the overall structure of the original cliff, resulting in criss-crossing cracks and dangers. The dangerous rock mass will not only threaten the safety of cultural relics, but also May injure visitors.
The protection and repair work, both official and private, has never been interrupted, and traces of ancient restoration and painting can still be seen on some stone statues.
In the Tang Dynasty, a "human"-shaped drainage ditch was excavated above the Fengxian Temple to prevent the leakage of water from eroding the Buddha. "A Record of Eleven People Cultivating Buddhahood as Deputy Secretary Hu of Dongba".
In the 1960s, several professors from China University of Geosciences went to Longmen Grottoes to conduct geological surveys. annual research plan.
The Fengxian Temple reinforcement project from 1971 to 1974 was the first large-scale grotto maintenance and reinforcement project in China. The chemical grouting and steel anchor rods used at that time effectively prevented the collapse of the surrounding rock of the grotto and the collapse of the carvings.
The "Longmen Grottoes Comprehensive Treatment Project" implemented from 1987 to 1992 has also curbed the water seepage in the caves, repaired the ancient drainage ditch of Fengxian Temple and continued to Wanfo Cave, and the tourist road leads to the main caves and Longmen Grottoes. The overall appearance has been greatly improved.
Ma Chaolong said that the role of the project at that time has continued to this day. Although there are seams and repairs, there is no major repair.
two overhauls
From 1971 to 2021, the two major repairs of Fengxian Temple in Longmen Grottoes were separated by 50 years.
The 67-year-old stonemason Liu Jianshe is the only protector of the Longmen Grottoes Research Institute who has participated in the overhaul of Fengxian Temple twice.
Liu Jianshe participated in the last protection project with his father when he was 17 years old.
Liu Jianshe said that the Lusena Buddha at that time can be described as tragic. There are holes on the top of the head and the body. From the hairline to the lower jaw, a 3-5 cm gap runs through the left face, and the left nose and lips are missing. , the right arm is shaky, and the carving on the chest of the statue of the king on the west side of the south wall of the big statue niche collapses to the ground, and needs to be hoisted and returned to its place.
In order to reinforce the right arm of the Lucena Buddha, the workers used an ordinary round steel with a length of 4 meters and a diameter of 24 mm, which was inserted vertically into the stone body from the crack surface through drilling, and then grouted into the hole, and finally blocked.
According to the data, 20 bolts were used at that time, and the grouting amount was 1200 kg.
In November 2020, the General Office of the State Council issued the "Guiding Opinions on Strengthening the Protection and Utilization of Grotto Temples", which clarified ten main tasks. The first one is to increase the rescue protection of grotto temples.
Since then, the water leakage treatment and protection project of Fengxian Temple in Longmen Grottoes (reinforcement of dangerous rock mass) has been started, and the project has been submitted for approval in strict accordance with the procedures of project establishment, survey, design, and program approval.
The project has been approved by the State Administration of Cultural Heritage and will be implemented in accordance with the protection plan approved by the State Administration of Cultural Heritage and approved by the Henan Provincial Administration of Cultural Heritage in June 2021.
Ma Chaolong said that the protection project is to repair the dangerous rock mass on the top and both sides of the Buddha, and does not involve the body of the Buddha.
On the square in front of Fengxian Temple, an exhibition board was set up to introduce the overhaul in detail. The researchers used ground penetrating radar detection, infrared imaging technology, 3D scanning mapping digital technology, etc. to carry out the preliminary survey, design and program preparation of the project.
At the construction site, the "Fengxian Temple Fissures and Water Seepage Disease Survey Map" compiled using 3D scanning surveying and mapping results completely showed the public the "root" of Fengxian Temple - structural fissures.
During the project, the staff took a combination of blocking and dredging and drainage measures, mainly completing 2,806 square meters of micro-crack sealing and grouting on the top of the Fengxian Temple area, repairing 106 meters of ancient drainage ditches, adding 89.4 meters of drainage ditches, and adding 62 meters of drip eaves. , 12 pressurized water test holes.
Dangerous rock mass has always been the main disease threatening the safety of cultural relics.
The engineering team adopted the method of combining rescue protection and preventive protection, and adopted the reinforcement measures of bolt anchoring combined with chemical grouting bonding for the dangerous rock mass of Fengxian Temple.
In this project, 68 large and dangerous rock masses were reinforced, 1107 square meters of fractured rock masses were bonded, 600 square meters of passive protective nets and 2970 square meters of active protective nets were installed, which provided a guarantee for the safety of cultural relics and tourists.
Blocking water seepage points on a 20-meter-high scaffold is tantamount to "embroidery in the air".
Liu Jianshe told reporters that the edge of the block should be in perfect harmony with the grotto body, and it should not overflow. "This is a test of craftsmanship and patience."
This time, metakaolin grouting material was used for the treatment of water leakage, which is non-toxic and environmentally friendly. The effect of water control is relatively good. For the sealing of the cracks on the surface of the caves, a new type of repair mortar was used. For the reinforcement of dangerous rock mass, fiberglass bolts were used Replacing the original threaded steel anchor rod, it is lighter in weight, more corrosion-resistant, and has greater tensile strength.
With 40,000 meters of steel pipes, 8,000 square meters of protective nets, and 6,900 square meters of scaffolding, it took a lot of work to build the "full hall" for the overhaul of Fengxian Temple.
For the purpose of protecting cultural relics, the scaffolding is required not to touch the wall, but also to keep a distance.
The construction personnel adopted the technology of "suspension frame rod", connected the scaffold with rock mass anchor points, pulled the reinforcement bars diagonally, and installed anti-fall nets and protective nets to ensure that the frame was more stable.
windfall
In the process of the project, with the help of scaffolding, Longmen Grottoes joined a number of colleges and research institutes to form a scientific research team. Resonant frequency imaging, ultrasonic nondestructive testing and other high-tech methods have detected and analyzed the surface moisture content, surface pigment composition, rock mineral composition, surface temperature of the Buddha body at different times, magnetic susceptibility, hardness, and surface repair layer of the Buddha's body. The technical parameters that characterize the objective existence state of the cultural relics, such as thickness and rock integrity of the Buddha's body, provide basic information for the analysis of the degree of disease development and its causes, and form a complete "physical examination report" for grotto diseases.
Ma Chaolong told reporters that modern technology is playing an increasingly significant supporting role in the protection and utilization of grotto temples, helping to realize the transition from rescue protection to preventive protection.
According to the "Physical Examination Report", it is determined that the bolt reinforcement measures adopted in the project 50 years ago are effective so far, and can effectively improve the stability of the structure of the Lucena Buddha.
The non-destructive "physical examination" also detected "unexpected gains". The group of sculptures in the large statue niche was detected with gold and silver elements in a large area; Puxian Bodhisattva's face generally has a white smooth coating. After analysis , the main component is lead white.
"Lead white is an important pigment for ancient paintings and cosmetics. It not only provides a good interface for pigment adhesion and gold foil bonding, but also plays a certain role in resisting natural weathering," Ma Chaolong explained.
On the right side of the Buddha's right side, the right eye of Samantabhadra Bodhisattva is preserved. The complete glass eyeball is dark green, with a uniform texture and brilliance. The left eyeball retains the outer half of the eyeball.
Although there are no eyeballs in the eyes of the Lusena Buddha, from the trumpet-shaped wedges similar to Puxian Bodhisattva, it can be inferred that the statue should also have eye structures similar to Puxian.
When you walk to the head of the Buddha, you will find that the face of the Buddha is very well protected, except for some old shell-shaped and long scars, the tip of the nose and the corner of the mouth are damaged and peeled.
The lips of the Buddha are slightly closed, the corners of the mouth are deeply sunken, the left ear has traces of green paint, the head of the Heavenly King on the north wall, and the hair crowns and clothing patterns of several other statues are distributed with a small amount of green, purple, red and other painted pigments.
A three-purpose
Shi Jiazhen will be the director of the Longmen Grottoes Research Institute in 2020. Before that, he has been the director of the Luoyang Cultural Relics and Archaeology Research Institute.
The 4 projects he presided over were rated as the top ten new archaeological discoveries in the country of the year.
This Fengxian Temple seepage water treatment and protection project is a rescue restoration. At the same time, archaeological discoveries and data collection are used to provide a basis for the next step to formulate the overall 5-10-year protection plan of the Longmen Grottoes.
Relying on scaffolding, a three-purpose machine is Shi Jiazhen's innovative move.
"In order not to affect the viewing of tourists, the original shelf was set aside for the entire body of the Lusena Buddha. Dean Shi acted resolutely and did what he said. After discussing with the designer and the construction side, he began to layer the shelf, adding boards to each layer. It was added in front of the Buddha statue," Gao Junping, director of the Longmen Grottoes Information and Data Center, told reporters.
"We entered the site on April 20 to collect data by multi-image photogrammetry with the help of scaffolding, which was divided into more than 500 units. The statues found this time are close-fitting with gold foil and glass eyes. Using digital technology, it is possible to realize the large-scale survey of Fengxian Temple. The shape and painting of the niche are restored virtually, and the original photosensitive resin print is output to reproduce the grand scene of the Tang Dynasty.”
In Gao Junping's view, the cultural relics of the cave temples have been in the open-air natural environment for a long time, and objectively speaking, they will eventually die out. While protecting and delaying the cultural relics, it is urgent to establish digital archives for digital protection.
With the blessing of three-dimensional digital technology, immovable grotto statues can go out and come alive.
Lu Wei, director of the Longmen Grottoes History and Humanities Research Center, said that Dean Shi has always emphasized that the archaeology of the cave temples is the best way to protect the Longmen Grottoes.
The purpose of the archaeology of the cave temple is to maximize the data and information of the cultural relics. After data analysis, digital technology is used to restore the authenticity of the cultural relics, so as to reproduce its original appearance and experience.
Taking advantage of the rare "full house", from June to July, Lu Wei led a team to carry out a comprehensive archaeological survey of Fengxian Temple.
In the investigation of architectural relics, dozens of small holes on the eaves of the niche and dozens of square holes in the top of the niche were found. Among them, there is a row of square holes in a straight line from north to south on the top of the niche, which is usually difficult to find and measure. There are stone single-headed arches in the beam holes on the north and south walls, with beveled surfaces at the ends; small square holes and wedge-shaped grooves are found in the inner bottom of some square holes for the first time. Architectural characteristics, construction and era of construction are of great value.
Lu Wei said that in the investigation of the carvings of the large statue niches in Fengxian Temple, the team members carried out detailed measurements and comprehensive written records and high-definition photos of all relics, including buildings and statues, and obtained a large amount of accurate measurement data. It is important to clarify some early data.
In addition, it was also found that the complex and exquisite decorative patterns in the backlight and headlight of the Lusena Buddha, such as tangled branches, lotus patterns, etc., there are also exquisitely carved music and music carvings on the left and right sides of the backlight, including maiko, music ten There are many musical instruments, including drums, horizontal flutes, straight-necked pipa, curved-necked pipa, Ruan Xian, horizontal flute, 筚篥, Konghou, Sheng, etc., which reflect the aesthetic ideas, popular patterns and court music of Luoyang, Chang'an, East and West Beijing in the Tang Dynasty respectively. part of the face.
Duck decoration is carved in the corolla of Samantabhadra Bodhisattva on the right side of the Lushena Buddha; the armor of the statue of Tianwang is ornately decorated, and there are birds and dreaded faces.
During the Kaiyuan period, more than 40 Buddha pedestals of the same height were excavated by 106 internal servants including Gao Lishi to pray for the blessings of Emperor Xuanzong of the Tang Dynasty. There were more heavenly kings, warriors and yakshas carved with them.
Lu Wei said that there was no prior attention and research, and it was difficult to conduct a comprehensive investigation.
In this investigation, it was found that there are a large number of carvings, strange carvings, and various combinations, which are very interesting, many of which are rare in Longmen.
The archaeological report of Fengxian Temple will also be completed before the "14th Five-Year Plan", Lu Wei said. At the same time, the archaeological report of Guyang Cave, Dongshan Kanjing Temple, and the north area and Xiangshan Temple will also be completed.
Gantry Mode
On July 29, most of the scaffolding in front of Fengxian Temple had been removed.
In Guyang Cave, Li Xiaoxia and several colleagues of the Longmen Grottoes Research Center’s History and Humanities Research Center are standing on the shelf doing the transcript part of the archaeological investigation report, “This work requires us to analyze the natural fissures, collapses, and weathering that we saw at the site. And man-made robbery, protection and restoration, ancient carving relics, etc. must be recorded comprehensively, comprehensively, and indiscriminately.”
Guyang Cave is the earliest and richest grotto excavated in Longmen Grottoes. It was excavated in the Taihe period of Emperor Xiaowen of the Northern Wei Dynasty (493 years). The cave is 11.2 meters high, 6.9 meters wide and 13.7 meters close. The scale is extremely grand. Even the top of the cave is covered with more than 1,000 niches of different sizes and forms.
Most of the shrines in Guyang Cave are engraved with "Statue Inscriptions", with as many as 800 pieces, which is the cave with the most preserved statue inscriptions in Chinese grottoes.
The light inside the cave is dark, humid and hot, and the scaffolding divides the cave into 6 layers from the top of the cave to the ground. Even if it is close to identifying the inscriptions and patterns, it is very difficult to see. Li Xiaoxia told the new colleagues, "Look hard, see clearly, and look carefully. , until there is nothing to see."
In Guyang Cave, the Information and Data Center of Longmen Grottoes Research Institute is doing another thing - through 3D reconstruction and mapping, to obtain high-precision, high-resolution, real and complete cave data, for the protection, research, display and development of Longmen Grottoes. Management work provides basic data.
Gao Junping told reporters that the most important thing for the digitalization of the Longmen Grottoes is to scan all the caves, and then establish a scientific and systematic digital file, which can achieve the purpose of permanent preservation and orderly utilization; Combining research, archaeology, restoration, disease monitoring, etc., digital protection can be said to be the most fundamental means of protection.
The digitization work of Longmen Grottoes also has another main direction, that is, the research and display of the virtual assembly and restoration of destroyed cultural relics and scattered cultural relics.
In 2021, the Longmen Grottoes Research Institute proposed the concept of digital virtual restoration of diaspora cultural relics of "friendly cooperation, multi-track integration, data aggregation, and achievement sharing", and used new technologies and new methods to create a "longmen model" of "data aggregation" of diaspora cultural relics at home and abroad. ".
The reporter learned that the Longmen Grottoes Research Institute has used 3D printing technology to restore the four niches of Guyang Cave, as well as the missing Buddha heads such as the neutral Buddha on the outside of the King Kong Lishi on the north wall of Fengxian Temple, so that they can be realized in the virtual space. "Heads and Heads are One", it also cooperated with the Plastic Arts Center of Xi'an Jiaotong University and the East Asian Art Center of the University of Chicago to jointly carry out a three-dimensional data collection and physical restoration project of scattered cultural relics including the "Emperor and Empress Ritual Buddha".
Shi Jiazhen said that the digital results of the Longmen Grottoes must be transformed, and the archaeological results must be combined with history, culture, religion, and art to conduct in-depth research. Only through in-depth research can the information and value of cultural relics be fully explored and our ancestors. The outstanding traditional cultural heritage left behind will be fully released.
The Kanjing Temple on the north side of Wanfogou in Dongshan Mountain of Longmen Grottoes is one of the most important caves in the Longmen Grottoes in the Tang Dynasty. The 29 Arhat sculptures have a strong realism style. Lotus petals, outside the caisson, there are six flying bodies flying in circles, full of momentum.
The team of a three-dimensional technology company in Beijing has been collecting data here for three months, "using high-tech means to extract the remaining information of cultural relics, cliffs, rocks, caves, statues, reliefs, caisson, environment, etc., every inch must be scanned. to ensure the authenticity and integrity of the data”, and then conduct research, and fit the multi-image photogrammetry with the laser-scanned model, so as to restore the authenticity and reproduce the initial style of the cultural relics.
Entering the digital cave of Jingshan Temple in the computer, walking through the cave is like walking from one room to another, and the smoke and diseases on the walls are also clear at a glance.
Click the mouse, you can raise your viewing angle to the top of the cave or down to the bottom of the cave, and there will be no distortion at any angle.
Feel free to zoom in on the details, such as the little Buddha on the backlight of the main Buddha statue, click the top of the head and the soles of the feet with the mouse to calculate the most accurate height, and circle a piece to calculate the area and volume.
"You can't feel that way on the ground."
Gao Junping said, "Everyone is doing 3D, but the authenticity and precision are completely different. The high-precision modeling of these cultural relics exhibits constantly put forward higher requirements for virtual reality modeling methods and data acquisition equipment, and also promotes development of virtual reality”.
"In the future, when a three-dimensional model of the big statue is built, wearing a VR headset and looking at the Lusena Buddha will be as close as you are when you look at it on the scaffolding today," said Gao Junping.
Beijing News reporter Liu Min