What is the current situation of the Great Wall? What are the reasons for its destruction?

1. Factors that damage the Great Wall construction

Classification (force majeure and force majeure/nature and humanity/slow and fatal)

Force majeure:

Protective measures for the strength and sustainability of the damaged areas

The Great Wall that is eroded by wind on ridges, Gobi plains, and wind vents is prone to wind erosion damage due to the lack of protection from plants or terrain.

Case: The difference between the windward and non-windward sides of the same watchtower

The Great Wall on the ridge near Lierkou, Shanxi

The Han Great Wall and Yadan on the Gobi Materials with different landforms have different effects

Build windbreaks and spray protective agents all year round

Rainwater

Erosion of rammed earth walls and earth-rock ramming that have damaged the waterproof layer Walls, etc.

Exhibition: Waterproof structure on the Great Wall wall

Due to rain erosion, expansion of rammed earth, and expansion of ice, water and soil on the wall are lost, and the bricks are separated from the wall. .

Case: Separation of wall and cladding bricks, rainwater soaking in watchtower. Severe

Prevent damage all year round, repair waterproofing layers in key areas, and spray protective agents

Acid rain

Corrosion Acid rain damages the binder - lime, and also damages the binder - lime. The stone carvings and bricks of the Great Wall were damaged. Lightweight

Long-term environmental management, spraying protective agent

Floods

Debris flows The Great Wall passing through valleys, ditches, and rivers is easily damaged by floods and debris flows. Serious

One-time destruction cannot prevent

Plants

Animals and plants grow on the Great Wall, causing damage to the waterproof layer; animals dig holes and eat plant roots, causing the waterproof layer The damage is light

It cannot be prevented or grazing is prohibited for a long time

Earthquakes in northern my country are earthquake-prone areas

The cases are serious

There have been cases for decades It cannot be prevented in one cycle

Geological subsidence is caused by groundwater, gravity and other factors, resulting in serious damage

It cannot be prevented in some areas

Lightning and lightning cause damage to buildings and cause Fire

Case: Xiaojinshan Building was struck by lightning and is prone to occur during the rainy season

Tourist areas can consider lightning protection devices every year

Natural collapse

The Lost Great Wall collapsed due to its construction quality, aging of the binder, and its own gravity

Serious

Partially unable to prevent and control

Natural factors: (Establish natural factors Mathematical model of the destruction of the Great Wall)

Human factors:

War: War caused the direct destruction/destruction of the Great Wall wall, and the Great Wall was destroyed to build fortifications for the war, etc.

Non-force majeure:

Human factors:

People on both sides of the Great Wall demolished the wall for production and life

Transportation development

Tourism construction

Others (reservoir/film and television)

Tourists

2. Lifespan of the Great Wall

Due to the Therefore, we cannot accurately measure the extent of damage to the Great Wall and measure the lifespan of the Great Wall. So we propose an indicator to measure the Great Wall: half-life. We define the half-life as the time when the ruins length of the Great Wall at a certain stage is reduced to half the initial length of the Great Wall

The lifespan of the Great Wall = the construction time of the Great Wall + life expectancy - lifespan reduction caused by natural factors - reduction caused by human factors life.

Partial lifespan of the earthen Great Wall=

Partial lifespan of the stone Great Wall=

Partial lifespan of the brick-clad Great Wall=