On July 6th, on the occasion of Liangzhu Day in Hangzhou, Laohuling Ruins Park was officially opened to the public. At present, as the only site of Liangzhu Ancient City Site that displays the profile structure of water conservancy system, Laohuling Ruins Park, with its most authentic appearance, reveals to the world the creativity and scientificity of Liangzhu ancestors in utilizing and transforming the natural environment, which is of great significance for the world to understand the emergence and development of Liangzhu Ancient City and even the origin of Chinese civilization.
The peripheral water conservancy system of Liangzhu Ancient City is an important part of Liangzhu Ancient City Site Heritage Area, located in the northwest of Liangzhu Ancient City. The influence area of the whole water conservancy system is about 100 square kilometers. It is composed of 11 artificial dams, natural mountain and spillway, such as Gukou high dam, plain low dam and piedmont long dike. It is the earliest large-scale water conservancy system discovered in China and the earliest flood retaining dam project discovered in the world.
Laohuling Dam belongs to the Gukou high dam system of the water conservancy system outside Liangzhu Ancient City. The dam itself is 140m long and 100m wide. From a distance, the outer shed for protection is like a huge water drop, lying in the narrowest position between two small mountains.
According to reports, from the moment of archaeological excavation, the sites of Liangzhu ancient city site have taken into account the follow-up protection work. In order to meet the needs of protection and exhibition at the same time, Laohuling Dam Site innovatively constructed a “water drop” protection shed with a strong sense of science and technology on the dam body. The structure adopted the form of spatial reticulated shell to cope with the stress problem of irregular terrain on the site and ensure the stability of the structure. At the same time, the combination of strip foundation and independent foundation was adopted to protect the original topography of the dam body and avoid the damage of the dam body by the building as much as possible. Into the inside of the “water drop”, there is a protective cover made of heated glass material on the dam section, an anti-seepage film is laid on the roof, a drainage ditch is built at the bottom, and shallow root turf is planted on the surface of the dam body, which not only reduces the destruction of the site soil by rain erosion, but also plays a role in marking and displaying the site itself, which has effectively prevented the problems of water seepage, dry cracking, surface pulverization and shedding, discoloration and biological diseases that are often encountered in the soil sites in the humid environment of the south of the Yangtze River, and effectively accumulated.
In the park, the audience can see that at present, the section of Laohuling Dam Site has been found to have obvious grass-covered mud structure through archaeological verification, and the paving methods are staggered horizontally and vertically. The reason for using straw to wrap mud is the same as the straw bag for water conservancy, which is a kind of reinforcement technology. It is also a technology commonly used in the construction of water-facing soil platforms, dams and other facilities in Liangzhu period, which can accelerate the consolidation of the dam body, increase the tensile strength and make it difficult to collapse. According to reports, in addition to grass wrapped in mud, a lot of soil is needed for the construction of Laohuling Dam. The research shows that the total earthwork volume of Liangzhu water conservancy system is about 2.88 million cubic meters. It is a huge and extraordinary project designed and built under the productive conditions at that time. Engineering planning, design, material collection, transportation, production, construction and other processes need considerable management and organization ability, and need to be supported by a regional state-level public power. The whole project reflects the functions of flood control, water storage, irrigation and water transportation of the water conservancy system around the ancient city in Liangzhu period, as well as the scientific engineering and technical aspects of water resources management such as dam site selection, foundation treatment, dam material selection, filling technology, structural design, etc. in the early days of human beings, and reflects the overall planning ability of early urban and water conservancy projects in China. Its construction accumulated experience for the organization and management of large-scale engineering construction in Liangzhu period, and laid the foundation for the formation of Liangzhu country.
On July 6, 2019, at the 43rd World Heritage Conference of UNESCO held in Azerbaijan, the site of Liangzhu Ancient City was successfully listed in the World Heritage List. On June 19th, 2020, the Standing Committee of Hangzhou Municipal People’s Congress set July 6th, the successful date of the application of Liangzhu Ancient City Site, as “Hangzhou Liangzhu Day”.
(Xu Xiuli)