In order to ensure the safety of the slope and its environment, it is necessary to take certain support, reinforcement and protection measures for the slope. Commonly used supporting structure types are:
(1) gravity retaining wall;
(2) buttress retaining wall;
(3) Cantilever retaining wall;
(4) plate rib or lattice anchor retaining wall support;
(5) Pile row anchor retaining wall support;
(6) Bolting and shotcreting support;
These traditional slope projects mainly emphasize its strength and efficiency, but often ignore its damage to the environment; Ecological slope protection, as a combination of geotechnical engineering and environmental engineering, has both protection and environmental effects, and is an effective means of slope protection and slope stabilization.
Ecological slope protection type
2.( 1) Artificial grass planting for slope protection
Artificial grass planting for slope protection is a traditional plant protection measure, and grass seeds are simply planted on the slope by hand. It is widely used in soil cutting and embankment slope protection projects with low slope height and gentle slope, which are suitable for grass growth.
Features: simple construction and low cost.
Disadvantages: Due to uneven sowing of grass seeds, it is easy to be washed away by rain, and the survival rate of planting grass is low, which often fails to achieve satisfactory slope protection effect, resulting in gully erosion, topsoil loss and other slope diseases, leading to a large number of slope disease treatment and restoration projects, making this technology less applied in recent years.
(2) Hydraulic spray seeding and grass planting for slope protection
Hydraulic spray sowing and planting grass for slope protection is a newly developed slope plant protection measure abroad in recent ten years. Grass seeds, fertilizers, adhesives, paper pulp, soil improvers and pigments are mixed with water in a mixing box according to a certain proportion, and then sprayed on the slope by mechanical pressure to complete the grass planting construction.
Features: ① Simple construction and high speed;
(2) The construction quality is high, and the grass seeds germinate quickly and evenly by spray sowing;
③ Good protection effect. Under normal circumstances, the coverage rate of plants on the slope can reach more than 70% after one month of spray sowing, and the protection and greening functions will be formed after two months;
④ Wide applicability. At present, hydraulic spray seeding and grass planting are widely used in slope protection and greening projects of highways, railways, urban construction and other departments in China.
Disadvantages: ① The ability of soil fixation and water conservation is low, which is easy to form runoff ditch and erosion;
(2) Builders tend to cut corners, make fakes, and form superficial phenomena;
③ Due to improper variety selection and insufficient mixture, it is easy to cause soil erosion or gully erosion in the later stage.
(3) Slope protection by exotic plants
Exotic soil vegetation slope protection is made of water-retaining agent, adhesive, anti-transpiration agent, particles, plant fiber, peat soil, humus soil, slow-release compound fertilizer and so on. After being stirred by special machinery, it is blown to the slope to form exotic soil with a certain thickness. Then, the selected seeds, wood fibers, adhesives, water-retaining agents, compound fertilizers and slow-release nutrient solutions are stirred with a sprayer and sprayed on the exotic soil on the slope.
Advantages: ① the matrix and seeds can be formulated according to geological and climatic conditions, with wide adaptability;
② The foreign soil is firmly combined with the slope;
③ The soil layer has good permeability and fertility;
④ Good drought resistance;
⑤ High degree of mechanization, high speed, simple construction and short construction period;
⑥ The vegetation protection effect is good, which can basically maintain the normal growth of plants without maintenance;
This method is suitable for slope of rock foundation, weathered rock and hard sand, road slope, mine, reservoir area and wasteland with small slope.
Disadvantages: it is required that the slope is stable, the slope erosion is slight and the slope is large, which is not suitable for long-term submerged areas.
(4) Laying turf:
Paving turf for slope protection is a traditional plant slope protection measure. Natural turf is laid on the slope manually.
Features: simple construction, low project cost, short time of turf formation, quick slope protection effect and less restriction by construction season.
It is suitable for slope protection engineering of soft rock with various soil properties, strongly weathered rock layers, poor diagenesis, easy source of turf nearby, high and low slopes and gentle slopes. It is one of the most widely used traditional slope plant protection measures.
Disadvantages: Due to the difficulty of early maintenance and management, the newly paved turf is easily affected by various natural disasters, which often fails to achieve satisfactory slope protection effect, resulting in slope disasters such as gully erosion, topsoil loss and landslide. As a result, a large number of slope disease treatment and restoration projects have been produced. In recent years, due to the shortage of turf sources, the role of laying turf for slope protection has been gradually limited.
(5) Ecological bag slope protection:
Ecological bag slope protection is a kind of slope protection technology which uses artificial geotechnical materials to make ecological bags, plants grow in ecological bags filled with soil, and slope protection and environmental restoration are carried out.
Features: water-permeable, air-permeable, impervious to soil particles, good adaptability to water environment and humid environment, and basically no seepage pressure on the structure. The construction is quick and convenient, and the material handling is light.
Disadvantages: Due to the limitation of space environment, the living conditions of vegetation in the later period are limited and the overall stability is poor.
(6) Grid ecological slope protection
Grid ecological slope protection is a grid composed of bricks, stones, concrete blocks, cast-in-place concrete and other materials. Plants are planted in the grid to form a comprehensive slope protection system of grids and plants, which can not only play the role of slope protection, but also restore ecology and protect the environment.
Grille ecological slope protection combines engineering slope protection structure with plant slope protection, and the slope protection effect is very good. Among them, cast-in-place grid ecological slope protection is a new patented slope protection technology, which has the advantages of strong slope protection ability, simple construction technology, reasonable technology, economy and practicality, and is a new generation of ecological slope protection technology with great practical value.