Our reporter Yu Lishuang
Dangers such as collapse, cracks, deformation of the top of the coupon, and poor drainage are all eliminated, and the style remains simple.
Yesterday, Huairou Great Wall No. 80 enemy station rescue and reinforcement project was completed and accepted.
This is one of the 10 Great Wall reinforcement projects in this city this year.
Yesterday, Huairou Great Wall No. 80 enemy station rescue and reinforcement project was completed and accepted.
Photo by our reporter Gan Nan
The Qilianguan Great Wall is located in Yanqi Town, connected to the Mutianyu Great Wall to the west and Lianhuachi Great Wall to the east.
The fourth enemy Taiwan from Qilian Pass to the west is the No. 80 enemy Taiwan on the Huairou Great Wall.
The enemy platform has two floors above and below, with a height of more than 11 meters, a length of 11.6 meters, and a width of 9.6 meters. The depth and surface width are very large.
The first floor of the enemy platform is in the shape of "Hui". There are 4 coupon doors on the small internal "kou". The corners of the corridors in the middle of the two "kous" are also arch-shaped.
Part of the wall remains in the second floor shop, and the west wall is relatively complete.
After a heavy rain last summer, the Great Wall protectors discovered that the partially collapsed southern wall of the enemy Tainan completely collapsed, causing changes to the entire main structure, deforming the first layer of the voucher, and crumbling the bricks on the top of the voucher.
The gable on the second floor is also tilted to the south.
"This is the only way for villagers and travel friends to go up the mountain. When passing through the enemy platform, the bricks on the voucher above their heads seem to fall at any time. It is very dangerous!" said Zhao Rufei, the person in charge of Yanqi Town Cultural Service Center. The No. 80 enemy platform was included. In 2020, there will be 10 Great Wall rescue and reinforcement projects in the city.
The collapsed south wall, deformed arch and top drainage are the three key points of the project.
According to Zhao Peng, the person in charge of the engineering design unit, if the top support measures are taken, it can only be an emergency, and cannot fundamentally eliminate the danger of coupon topping.
If the method of "demolition and masonry" is adopted, the safety of the second-story gable wall may be endangered.
During the construction process, the relevant parties visited the site several times, and the risk relief plan for the top of the coupon could not be determined. It was only after the workers tried to remove the shaky coupon top bricks in a small area that the main body of the second-story gable was pressed on the first floor. Above the wall, dismantling the voucher roof will not endanger its structural safety.
"In this way, we decided to support the second-story gable first, and then, based on the principle of minimum intervention, partially demolish the top of the first-floor coupon." Zhao Peng introduced.
After the completion of the project, all the dangers of the top of the coupon and the gable were eliminated.
There was a roof on the second floor of the No. 80 enemy platform, but it has collapsed. The rain fell directly on the ground and poor drainage was an important reason for the collapse of the enemy platform.
In order to solve the drainage problem, another layer of bricks was built on the original ground on the second floor, and a water channel was left at the junction with the wall.
"This measure layer is not a cultural relics layer. If conditions are available in the future, if you want to further repair the enemy platform, you can remove the measure layer and build." Zhang Tong, director of the Huairou District Cultural Relics Office explained.
The original ground on the second floor of the enemy platform is covered with square bricks, and the measures layer is made of strip bricks, which embodies the "identifiable" and "reversible" principles of the cultural relics restoration project.
The bricks are mainly old bricks that cannot be built after the collapse of the No. 80 enemy platform, which guarantees the original appearance of the Great Wall from the appearance.
The mountain is higher and the danger is heavier. The construction of the No. 80 enemy platform rescue and reinforcement project is very difficult.
"The road up the mountain is too steep. We used mule teams to transport materials. The mules were reluctant to go up." Cheng Yongmao, the technical director of the construction unit, introduced that the large rocks on the outer base of the south wall rolled over. The ditch was buried by the collapsed bricks.
When cleaning up, first support the crumbling coupons and walls on the top of the enemy platform before digging a stone below.
The striped stones in the northeast corner of the base are still left on it. When laying, the remaining striped stones must be used as a benchmark and piece by piece upward.
"These big rocks, weighing five to six hundred catties, passed one by one, and eventually returned to their place with more than 90 big rocks."
On the same day, the No. 80 enemy station rescue and reinforcement project successfully passed the completion acceptance.
But for Great Wall Conservation, this is just the completion of the "emergency". Great Wall protectors and cultural relics departments also need to perform regular patrols to remove new dangers at any time.