"The seven quarries cover an area of nearly 82 acres, and each quarry provides a unique terrain to explore the regeneration potential under different scale and stability conditions. These holes dug in the landscape provide different development possibilities-from the structure above the cliff to the sunken aquatic plant garden in the quarry, and the changing water level in one of the holes makes the floating pavilion necessary. The elevated passage in the site stands on the existing aqueduct that is still in operation, connecting these completely different quarries. Through the overall coherent design, visitors can move freely above the potential disaster change geology and enjoy the ground landscape without obstacles. "

—————2020ASLA Awards Jury

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I. Construction background

20 18 China International Garden Expo was held in Nanning. Garden Expo Park is located in a hilly agricultural area by the river on the outskirts of the city, and there are a series of quarries in the southeast of the site. The organizing committee hopes to turn these quarries into distinctive gardens and become part of the exhibition at the Expo.

Two. Base profile:

The design area is about 33 hectares. There are seven quarries on the site, some of which have stopped mining for several years, and two of them did not stop mining until the success of the Expo. The mining face of the mine is cliff-broken, the pit bottom is uneven, the mountain in the field is broken, the cliff is towering, the surface is barren, the pool is bottomless, muck and stones are piled up, and rusty quarrying equipment is scattered all over the place.

Three. Design challenge

1.？ The geological conditions of the quarry are complex, and the rock wall is broken, which may lead to collapse and falling rocks, and there are potential safety hazards;

Solution: Put safety first when setting up facilities and visiting paths, and avoid dangerous areas while highlighting the landscape characteristics of quarries.

2.？ The ecological environment of the quarry has been seriously damaged, and the vegetation restoration is facing great challenges;

Solution: According to the goal of vegetation restoration in different quarries, the designer introduced soil to form planting areas with different soil thicknesses, thus creating conditions for habitat restoration. At the same time, these seven quarries look very similar, but in fact, the scale, shape and characteristics of each quarry are different. According to different site characteristics, the design adopts differentiated vegetation restoration methods and artificial intervention methods.

3.？ The terrain of the quarry is complex, so it cannot be designed according to the existing surveying and mapping drawings;

Solution: Through aerial scanning of unmanned aerial vehicle, three-dimensional digital models of all quarries can be obtained, which can be designed from beginning to end in three-dimensional space.

4.？ The water level in quarries is changing dynamically, especially in the last two quarries, and the water level has been rising continuously. There is no effective hydrological data reference for the design.

Solution: The design unit entrusts the local organization to record the water level change of each pit every half month, which provides the basis for the design.

How to recognize and treat these abandoned quarries? Do you regard them as ugly scars on the earth, and try your best to completely cover them up, or even decorate them so that people can't see the original traces? Or do you think they are witnesses of human destruction of the environment, and we should let nature take its course without human intervention and let natural succession gradually recover? Or do you recognize your own unique landscape and use the characteristics of the site to tap landscape resources to form a different landscape?

Four. Design overview

For seven quarries, according to their characteristics, according to local conditions, the diversity of quarry landscapes is preserved, and various restoration methods are used for manual intervention to a certain extent, showing various landscape types and various possibilities of ecological restoration, enhancing the value of landscape through artistic intervention, and letting people participate in the experience through different trail designs, so as to feel the restoration state of each quarry. At the same time, through the organization of the path, the integrity of the design language and the connection of the original canal, these seven quarries can become a whole again.

On the premise of ensuring the safety of the scenic spot, according to the environmental characteristics of the quarry, different strategies and means are adopted for design. For example, the sunset pool is particularly quiet, so it is designed as a quiet and thoughtful garden; Some sites have a lot of gravel, so they are designed as rock gardens; Some sites have no soil layer on the ground, so they can't grow tall plants, so they are designed as terraced gardens to create conditions for plant growth. Each quarry carefully chooses a good viewing angle and designs a viewing platform. Intervene in the structure, improve the artistry, and break the dreariness of the original dilapidated quarry. At the same time, the design adopted some ecological restoration measures, low intervention and laissez-faire self-repair.

Verb (abbreviation of verb) design rules

1.？ 1 Quarry (Luoxiachi)

The area is about 1hm? .

After the quarry stopped mining, groundwater seeped out to form ponds, which were used by nearby villagers to raise fish. At present, the pond is surrounded by stone walls, which is magnificent and heavy, showing the natural beauty of rocks, and the overall environment is elegant, in line with the traditional natural rock aesthetics.

Create the spiritual space of classical culture;

The pit pond is surrounded by a rock wall more than 400 meters long, and the space is closed inward, away from the noise of the world. Under the polishing of years, the stone wall presents vigorous textures and mottled traces, just like a magnificent natural landscape painting. The temperament of this quarry fits the traditional landscape aesthetics of China very well, and it can be transformed into a space with classical cultural spirit without too much pen and ink. In the design, the original stone walls are retained, and the stone walls and ponds are used as the landscape foundation, and waterfalls and waterside pavilions are added to create the artistic conception and atmosphere of sitting in the pavilion watching the water and lying on the porch listening to the waterfalls.

Spatial contrast (promote first and then suppress):

The only passage from the outside to the inside of the mine is the gap previously opened between rocks for transporting stones. Looking into the pit from this gap, you can see a large area of water, opposite which is a tall and beautiful rock wall. An irregular wooden structure was designed, which was embedded in a crack in the rock near the pond, extending from the crack in the mountain to the water's edge, and was named "Shuizhuju". The building passes through a narrow gap in the rock, and under the interaction between the roof and the rocks on both sides, it creates a tunnel-like space feeling. The narrow building extends to the pond at the end of the gap. With the expansion of venue space, it suddenly expands to both sides, resulting in drastic spatial changes and strong contrast between internal and external space, so as to strengthen and enhance the spatial experience of tourists. It's really "no way back is at the end of its tether, and there is another village."

Design of landscape and viewing space;

A waterfall was designed in the cliff recess opposite Shuizhuju, which became the focus landscape of the mine and added dynamic changes to the landscape of the quarry. The gurgling sound of water set off a quiet and distant atmosphere and became the finishing touch.

A path along the seashore connects four platforms at different altitudes, providing people with places to watch rocks, waterfalls and buildings from different angles.

Architectural design:

(1) Architectural structure and form: The design of architectural structure is inspired by local vernacular architecture and reflects regional characteristics. This building is a glued wood structure. In order to support the wide and irregular roof, the column network is dense, and a large number of inclined support structures are used. It seems complicated, but the logic is clear, which reflects the force transfer relationship in the wood structure system.

(2) Architecture and water environment: In order to adapt to the change of water level, the floor of the pavilion fluctuates with the water level;

(3) Building and rock wall environment: The roof of the building is three groups of continuous double-slope roofs, and the outside of the roof facing the water surface is intentionally raised to ensure that tourists can see the complete landscape on the other side as soon as they enter the platform. At the same time, the floor, columns and folding roof of the building form a broad frame view, which integrates the whole magnificent and heavy stone wall opposite.

2. The second quarry (water garden)

? The area is 0.4 hm? .

Surrounded by rock walls, only a gap on the north side can enter the pit, the bottom of the pit is gentle, and the lower part is flooded all the year round. Because the quarry has been abandoned for some time, many herbs and shrubs naturally grow in some areas of the gentle slope rock wall and pit bottom. The cliff on one side of the pit is 24m high, and the stone cliff is reflected in the water, which is quite spectacular.

The bottom of the pit is both land and water, and the water in most areas is not deep, which provides the possibility for vegetation restoration, including the planting of aquatic plants. So the location of the pit is the wet botanical garden.

Terrain treatment:

Two terraces are designed at the higher place of the cliff on the south side of the pit bottom, built with rubble retaining wall and covered with soil, and combined with the gentle slope extending from shallow water to the front of the retaining wall, creating conditions for planting wet plants and aquatic plants.

The height difference between the cliff and the bottom of the mine is 10m. The design abandons the direct step connection, and combines the landscape plank road, structures and platforms to deal with the tour path between the pit top and the pit bottom.

Plant landscape design:

Planting trees, shrubs and herbs on the highest platform creates an ornamental background for the garden and shields the broken rock wall with poor landscape effect. More than 40 kinds of aquatic and hygrophytic plants have been planted in combination with the platform and water environment.

Landscape road and architectural design;

Because the internal space of the quarry is small, it is not suitable to set up a circular path, and the height difference between the cliff and the bottom of the mine is large. If the steps are designed to allow tourists to enter the pit bottom, there will be potential safety hazards due to the long steps. Therefore, in order to weaken the feeling of stairs, ensure the safety of tourists and create more spatial changes, the tour path is divided into three sections, and different landscape structures are designed to transform the connection of height difference into a series of sightseeing and spatial experiences.

The first section, the highest section, is designed as a closed wooden box, which makes the internal space of the wooden box contrast with the open observation deck at the top of the cliff. It is not only a safe pedestrian passage, but also a small building that can rest in the shade. The end of the wooden box is opened, and a glass railing is set up to become an aerial viewing platform, where people can enjoy the rock wall and overlook the garden. The bottom of the wooden box is supported by irregular steel columns, which enhances the interest of the landscape structure and adapts to the rough and natural landscape characteristics of the quarry.

The second section is a few sections of spiral ladders leading out from one side of the wooden box, which are descended to a wide viewing platform by using a relatively closed wooden railing. This is the main stop for people in the garden, where they can enjoy the waterfront plant landscape.

The third section is a zigzag steel grating plank road leading from the observation deck, which uses light railings, passes through the wetland plant planting area and leads to the quarry pit along the waterfront, reflecting the blend of nature and manpower.

Scene design:

This treatment contrasts with the scenery after entering the garden from the entrance. A small viewing platform is designed on the other side of the water's edge, which echoes the large platform on the other side, and the ladder treatment connecting the cliff top and the foot of the mountain is taken as the opposite landscape. Here you can enjoy the scenery of the whole garden-water surface, aquatic plants, plank roads, ladders, wooden boxes in the air, rock walls and their reflections in the water, a perfect picture. ?

3. Quarry No.3 (Rock Garden)

The area is 0.4 hm? .

The foundation is more than half bowl-shaped, surrounded by rock walls on three sides, and the ground on one side is flat, with a lot of slag and muck piled up. The bottom area of about 1/3 is a concave area, and there is water after rain. Many native herbs grow in crevices of rugged rocks.

Imagine designing this quarry into an exquisite rock garden, displaying the plant landscape that grows tenaciously on barren soil.

In the design, the original slag, stone and muck are sorted out to shape the skeleton of the terrain, and then the planting soil is covered on it. Subtle topographic changes not only create different habitats such as dry and wet, but also provide conditions for different plants to grow, and also collect rainwater from the site to the lowest depression.

Desert plant landscape area:

Adjacent to the main garden road area, according to the change of the current height difference, a red sandstone platform with friendly and changeable scale is designed, and sand plants such as cactus and succulent pulp are planted to create a unique desert plant landscape. ?

Wild plant landscape area:

The gentle slope area in the middle shows the plant landscape of the wasteland. Low-level and fine plant communities are interspersed between rocks and gravel, forming a unique garden landscape. Exquisite garden roads meander through the plant community.

Wet Rock Park:

The bottom depression is designed as a wet rock garden, and the stream descends to the lowest pond layer by layer, showing different habitat landscapes of streams, stone beaches and ponds. Viewing platforms with different heights are designed at the edge of the depression, so people can overlook the wet rock garden below, enjoy the falling water of the stream and enjoy the rock wall landscape.

4.？ ? No.4 quarry (Junyatan)

One of the last two quarries to stop mining. After the quarry stopped mining, the groundwater infiltration area was about 1hm? A large green and clear pool.

The design set up platforms at the main observation points on the north and south sides.

The observation deck on the north side is a weather-resistant steel corridor on the edge of the quarry, with a long window facing the quarry, from which you can see the towering and steep cliff more than 40 meters above the water. The southern end of the promenade is hung on the rock wall, and people standing on the inside of the glass railing can overlook a pool of clear water at their feet and the opposite waterfront platform, which is thrilling.

On the south side of the quarry pit, a wedge-shaped platform protrudes from the crack in the rock and hangs on the clear water. A curved trestle is led out from the platform and connected with the lower waterfront platform. By covering the soil around the pit and the gentle slope in the pit, planting Phoebe bournei and some native shrubs and herbs will make the quarry alive and set off the preciseness of the cliff.

5.5 Quarry (Waterfall Lake)

The largest quarry is about 3.2hm? The mining depth is also the deepest, reaching 28m.

There are several layers of rock platforms at the bottom, and the cliff wall is broken. The residual rock points divide the pit into different spatial levels. With the stop of mining, groundwater gradually accumulates. According to the observation and analysis of water level, it is predicted that the whole quarry will become a lake.

In the design, two relatively shallow mining areas at the bottom of the quarry pit are raised above the water surface by covering the soil, and tall trees with moisture resistance such as Taxodium ascendens and Pinus tabulaeformis are planted to form an aquatic jungle, which brings green and vitality to the desolate pit. Then trestles with different heights are used to guide people into the inner space of the quarry pit, not just around it. The trestle crosses the water surface and the forest, leading to the observation deck at the height of the headland, and experiencing the changes of space and landscape in the exploration of descending and climbing. In order to increase the richness of the landscape, a waterfall is designed on the cliff opposite the trestle, and people can enjoy the wonderful waterfall landscape on the bridge.

6.？ ? No.6 quarry (terraced garden)

Area 0.7hm? .

On one side is the cliff of the quarry, and on the other side is the pond in the village. There is a complete set of sand and gravel production line equipment on site, which shows the history of on-site quarrying industry.

According to the characteristics of the present situation, the area is designed as a terraced garden with Nanning's characteristic flower border plant landscape, a romantic and gorgeous garden with post-industrial atmosphere. Several platforms meander along the south cliff, and their coverage thickness meets the needs of different plants. Most of the machinery and equipment are placed in the green space, and the vibrant plants form an interesting contrast with the rusty machinery. The road twists and turns under different platforms and the original overhead conveyor belt, and comfortable wooden armchairs are set on the roadside for people to rest.

7.？ ? No.7 quarry (Shuangxiuyuan)

Two small quarries 1000 square meters, located on the two wings of a hill, one of which is deep and has water all the year round; The other is shallow, with seasonal water accumulation. Because it has been abandoned for several years, all kinds of original pioneer plants have grown in the gaps between the two pits, and the landscape is simple and natural.

The design did not use human intervention, but only set up a circle of circular plank road on the undeveloped hillside between the two pits, so that tourists could overlook the quarrying pits on both sides and let people know the power of nature and its role in pit restoration. On the west side of the pit, a small platform near the water is set up, which echoes the circular plank road on the mountain. The plank road and platform are made of steel grating, which is transparent and permeable and will not affect the restoration of natural vegetation in the site.

8. Others

The original canal on the site is a witness to the agricultural history of the site. In the design, we reserved the canal as the water source of several water surfaces in this area, and continued its original function. An elevated footbridge was erected above the canal, which is connected with the tour path of the adjacent quarry gardens, forming a unique three-dimensional tour system in this area. In order to provide some basic services for tourists and show the concept and method of ecological restoration in the park, we designed a 600m? Information kiosk. The architecture of wood structure echoes the local vernacular architecture.

Design analysis and learning points

1.？ Key points of mine landscape design:

( 1)? In this kind of design, we should adjust measures to local conditions, start from the current site characteristics, give priority to protection, respect and show the site characteristics, design with minimal intervention, show its natural beauty, historical sculpture beauty and humanistic sculpture beauty, and present the original features of mine rock walls and pools;

(2)? According to the current landscape, design landscape points and scenic spots, plan and design the entrance and tour route of the pit pond on the basis of ensuring ecology and safety, and pay attention to the traffic connection from the top to the bottom of the pit;

(3)? Pay attention to the design of safety environment;

(4)? Pay attention to the use of materials;

(5)? Pay attention to the collection, treatment and application of water;

(6)? Pay attention to the treatment of terrain.

2. Mine disposal methods:

(1) Sightseeing plank road: around the top of the pit, beside the water at the bottom of the pit, above the water surface of the pit, and extending around the edge of the pit to the bottom of the pit;

(2) Sightseeing structures: where the height difference is large, combine structures to eliminate the height difference and ensure its safety; Set up landscape structures in places with good landscape sight, and integrate with the surrounding environment to form a landscape;

(3) Retaining the rock wall: combining water to form a waterfall, creating a landscape focus; Combine with the big water surface to form the reflection of rock wall water and form the landscape; Combining plants as the background of landscape environment;

(4) Terrace garden: combining with the terrain change of the pit, form terrace garden, and pay attention to the design of viewing surface and scenic spots;

(5) Water body design: retain the original pit and pool to create a natural atmosphere; Design waterfalls to create landscape focus; Design rain gardens in low-lying areas.

3.？ Transformation of old industries

( 1)? Industrial facilities are reserved for landscape facilities, such as sculptures;

(2)? The design adopts materials with industrial and cultural flavor, such as weather-resistant steel plate and stainless steel plate;

(3)? The original site was backfilled with waste materials, such as gravel and cinder, to shape the terrain and create various spaces.

Related knowledge expansion

1.？ Brown land: refers to the real estate that is actually or potentially polluted by harmful substances produced by development.

Basic characteristics: there may be some pollution and environmental problems; Not fully utilized; The nature of land can be industrial land, commercial land or other land, but mostly industrial land; It has certain development potential.

2.？ Restoration and regeneration of brownfield: By using certain technical means, by controlling pollution, restoring site ecological environment and improving site facilities, the polluted and abandoned brownfield will be re-developed and utilized to form land with other functions and uses, which will ultimately enhance the comprehensive ecological and economic value of the land and finally stimulate the vitality of the city.

Types: landfill, industrial brownfield and mine brownfield.

3.？ ? Pit brown land: land that is destroyed or polluted in the process of mining, mineral processing and smelting and cannot be used without treatment. Including abandoned mines, pits and construction land, storage land, traffic land, etc. Contaminated by mining activities; Including coal brown soil, oil-gas brown soil, metallic non-metallic brown soil (quarrying mine belongs to this type) and so on.