Global ecological restoration of abandoned mines

The Biville quarry at the top of Clairefontaine Canyon was closed in 1989 after 10 years of mining. The quarry pit is a 450m long, uniform width linear crack, a 45 degree slope barren and uneven, 20-40m drop.

The designers built it into a recreation area with a 3.5 square kilometer lake. The idea was not to hide the traces left by the stone mining process, but to preserve them as site features, simply to ensure continuity in the best locations for the natural restoration of the ecosystem, and then to introduce some vegetation to restore the abandoned quarry to a natural state.

The renovation includes the design of a series of facilities and equipment to direct the flow of water to the valley floor to form a lake. The lakeshore has been designed to accommodate the most popular leisure activity in the area - fishing.

To make it easier for visitors to enter the valley floor, the walls of the pit are built in the shape of steps, and each platform is lined with metal mesh and fixed stone as a barrier. At the same time, the form of the ladder allows runoff from the grass above to flow into the gutter, protecting the surface from water shock and erosion. The huge stone walls viewed from the valley floor become the most symbolic attraction in the area.

Adult trees are planted in strips on the site to resist wind erosion, and each section is planted according to its natural characteristics and topography.

03. Ecological restoration of Guri Mining field in Venezuela

For the first time, Venezuela has used water grass planting technology to ensure the rapid and effective formation of vegetation without the use of black soil and plant layers, and the ecological restoration of the earth dam quarry on the right bank of the Guri Hydropower Station is implemented at a very low cost, and is at the forefront of the application of water grass planting technology.

The Guri Project, located on the Caroni River in southeastern Venezuela, was constructed between 1967 and 1986 with a hydroelectric power plant, earth dam and rockfill dam, which required 40 million cubic meters of anti-seepage material to be extracted from a collection of about 700 hectares of forest not far from the dam.

Excavation of the mining site involves the removal of weathered gneiss, leaving exposed irregular concave surfaces and recesses that are susceptible to severe erosion by rain, resulting in poor sensory areas with topographic variations of up to 100m. In this regard, the Karoni Power Company has implemented a multi-faceted "ecological environment restoration plan" for the mining site, with the aim of restoring the ecological environment of the affected area during the construction of the Guri Hydropower Station.

The ecological restoration plan is divided into six stages: initiation stage, recovery stage, diagnostic examination stage, experimental stage, contract planting stage, and continuous treatment stage. The concept is to save nature by means of natural restoration.

The rescue measures mainly include: Select major local plant species and some introduced plant species as vegetation, plant a large number of local thriving trees under greenhouse conditions, plant resistant gramme seeds mixed with seeds proved to be suitable for the ecological and climatic conditions of the harvesting site, prohibit planting in the rainy season every year, and implement a protection plan suitable for the planting period after 3 years. Use biofertilizers and low chemical fertilizers to set up small oxidation ponds in flat low-lying areas with rainwater and dam leakage.

04, Shanghai Shimao Shenkeng Hotel

As the first hotel in the world to be built in a waste rock pit, the Shimao Deep Pit Hotel in Shanghai's Sheshan district is undoubtedly a strange project. Its construction method, building structure and traditional building requirements are very different, after completion or become the world's lowest elevation hotel, known as the world architectural miracle.

The "Deep Pit Hotel" is located at the foot of Sheshan Mountain in Shanghai Songjiang National Scenic Area. It is an abandoned pit with a depth of 80 meters. The deep pit was originally a quarry, and after decades of quarries, a deep pit with a circumference of kilometers and a depth of 100 meters was formed. Shimao Group has taken full advantage of the natural environment of the pit and has imaginatively built a five-star hotel that blends into the pit and complements it. This is a miracle in the history of human architecture, as well as a synthesis of nature, humanity and history.

Invested by Shanghai Shimao Group, the "Deep Pit Hotel" is the world's first five-star hotel built in the pit. The hotel is equipped with underwater scene suites, sky garden, spectacular waterfall, steel structure resistant to 9 earthquake buildings. In March 2013, the Deep Pit Hotel was officially started. On October 21, 2013, the wall and bottom rock of the pit were blasted for the first time, and the construction team expects that the hotel will be completed by the end of 2017, which may become the lowest altitude hotel in the world.