How to Protect the Terracotta Warriors

In order to protect the unearthed Terracotta Warriors, archaeologists have tried many ways, such as build shelters for them, protect their colorful coatings, clean the mould, stabilize the statues, and so on. Also, efforts have been made to improve the internal and surrounding environment of Terracotta Army through watering the ground, limiting tourists and purify the air.

Right on the original sites of Pit 1, Pit 2 and Pit 3 of Terracotta Army, archaeologists have built the shelters to protect the unearthed Terracotta Warriors from sunlight, wind and rain. Under the relative stable environment indoor, these cultural relics can be preserved for a longer period.

Originally, all the Terracotta Warriors were colorful. However, being buried in the damp underground for over 2,200 years, their colorful coatings, along with a layer of raw lacquer, stick weakly to the terracotta statues. Once unearthed, they will face the problems like oxidation, decreasing humidity, strong ultraviolet, acid gases and microorganisms. So, the coatings can quickly shrivel, crack, fade away and finally fall off.

Therefore, when excavating Terracotta Warriors, archaeologists will first spray protective agent on their colorful coatings, wrap them with plastic sheet and then send them to the laboratory. In this way, these relics can avoid the sudden change of surrounding environment. In addition, researchers have also developed an anti-shrivel agent to ensure the stable humidity of the colorful coatings. Once the coatings are moist enough, adhesive will be used to effectively fix them.

 See also: How to Repair the Damaged Terracotta Army Statues?

Once the dirty, damp and warm air is mixed with dust, exposed Terracotta Warriors can suffer from mould. In order to solve this problem, researchers have selected many mould inhibitors to suppress the formation of mould and moss on terracotta statues’ surface.

As we can see, most exhibited Terracotta Warriors are standing in the soil pit. So their bottom keeps contacting the soil. That’s why this part can be eroded by gathered capillary water and soluble salt in the soil. To handle this problem, archaeologists will put some waterproof and air-permeable geotextiles under the Terracotta Warriors as a barrier.

For fear that the precious Terracotta Warriors would fall down under earthquake or other circumstances, restorers add accessory apparatus into the figures’ bottom or their hollow legs. This technique can greatly stabilize the Terracotta Warriors, so they can be free from external shock. Of course, the apparatus can be taken out whenever it is needed.

Partition walls in the pits are also integral parts of the Terracotta Army. These neatly arranged soil walls can more or less decrease the weathering process to the terracotta warriors. When protecting partition walls, two factors need to be considered, shape and soil quality. For the former, researchers will use measuring instrument to know whether there exists deformation or displacement. For the latter, many tests will be conducted to figure out the porosity, water content, salt content, composition and weathering degree of the partition walls’ rammed earth and sintering soil.

In order to prevent the partition walls from cracking or collapsing, archaeologists will strengthen them through installing anchor rod or partial grouting. As for their surface, archaeologists will paint it with the mixture of mud, waterproof agent and dust-proof agent.

Displaying thousands of Terracotta Warriors, the Site Museum attaches crucial importance to its internal environment. Apart from the basic control of temperature and humidity, the staff members here also make efforts to reduce floating dust and facilitate ventilation. Here are two easy and effective measures.

Many tourists once saw the staff water the ground, and questioned whether it could damage Terracotta Warriors. Quite the converse, watering the ground is a protective measure. In fact, the watered area is for staff members to restore and study unearthed Terracotta Warriors, so many staff walk through this area every day. If it isn’t watered, its soil top will quickly crack and produce a large amount of floating dust. And the floating dust can deposit on exhibited Terracotta Warriors, especially harmful to those with colorful coatings. So, watering the ground is a good way to keep the soil moist and reduce dust in the air.

Someone doubts this action may harm the buried terracotta statues beneath the watered area. Take it easy. The reason is that due to the capillary effect, the water in the soil constantly moves upward and evaporate, and the quantity of sprayed water is too little to reach the buried terracotta statues. 

If many tourists crowd into the pits within a short time, a lot of dust, bacteria and, of course, carbon dioxide will be taken in and mix with the internal air. As you can imagine, the stale air will only speed up the erosion on Terracotta Warriors. Therefore, the Terracotta Army receives at most 65,000 visitors each day and staff members will guide tourists to other pits if there are too many in a certain one.

Controlling air pollution is the pressing concern to upgrade the environment outside the Site Museum. In earlier times, there used to be a lot of factories which emitted exhaust in this area. In order to decrease the sulphur content in the air, the Site Museum managed to close those factories by land requisition. Moreover, the Site Museum also relocated the residents in the neighborhood and established a vegetation zone of 200 hectares to pure the surrounding the environment.

The microenvironment of the excavation site is of vital importance. As mentioned above, the temperature, humidity, floating particles, harmful gases and UV intensity in the air can directly affect the oxidation and erosion of Terracotta Warriors. Thus, archaeologists use accurate equipment to monitor these indicators all the time.

Around the museum, the air pollution index should be measured every season, each season four days, and each day four times.

Inside, an environmental monitoring station is set up. Moreover, each pit’s temperature, partition wall temperature, ground temperature, humidity and airflow are also carefully recorded.
 

In short, the indicators mentioned here can help researchers make specific plans and take effective measures to preserve Terracotta Warriors as long as possible.

 Read more:
 How the Terracotta Warriors were Made
A Little-known Case of Terracotta Warriors Theft in 1987
 2 Destruction Accidents during Terracotta Warriors’ Exhibition Overseas