November 15, "lively" 10 years of frustration was quiet commercial street in Chengdu - Commercial Street, Guan backfill the site to complete protection. This date, China's largest Guan found buried, why the depths of the earth to return?
The answer entangled in the "water." In 2000, an area of about 1600 square meters of commercial street Guan site first emerged, the industry was identified as the ancient Shu large open late joint burial, was named in 2000 one of the top ten archaeological discoveries, and became the State Council announced The fifth national cultural heritage. However, a series of "title" has not eased Guan sites suffered "water" problem - Guan contact with air, the appearance of fast deformation. Guan testing experts found that the moisture content of up to 400% or more, it is difficult to adapt to the modern climate.
Before backfilling, Guan, more than 80 million each year protection costs. And outside experts have been carrying out technical exploration, has yet to find the best protective measures. Site of that year found more than 30 with Guan, only unearthed seven save the Chengdu Institute of Archaeology in the North Lake archaeological finishing base. Conservation professionals have tried to maintain the use of chemical drugs Guan original, but once to stop using drugs or environmental changes, Guan will happen soon, and shrinkage cracking, or even "beyond recognition." Experts say, can only delay the Guan cracking, Zaoxiu, but not fundamentally solve the "shrink" phenomenon.
At the same time, cultural workers and the graves at the site to build the temporary protection of the top shelf. Under the shelter shed in the protection of cultural relics "survival" With year-round humidity. However, a variety of fungi and bacteria also grow inside the pit, mice and termites often to "patronize" Heritage at any time at greater risk.
"Groundwater is also a great erosion of Guan." The experts said that early in 2001 and 2003, they had done twice on the pit walls of reinforcement anchor and long-term monitoring. "Low-lying pit, groundwater flow is more than year." Although the use of sump pumping groundwater, but also took away the soil pit, the site subject to a certain degree of damage.
In desperation, Guan only to return to the ground. Backfill protection is more mature international practices, sites after backfilling, can Guan at lower temperatures, very little oxygen and a good moisture environment, provide site protection for a longer buffer period. Approved by the State Administration of Cultural Heritage, heritage protection workers will shed demolition, site clearance within the sewage, the use of fine sand and clean soil to backfill the site. "Maintain the permeability of the site's breathable, easy-related technology is mature before the next excavation." Source: Sichuan Daily
