² Definition
Modern geosynthetic materials are a kind of artificial synthetic materials used in geotechnical engineering, mainly using plastics, chemical fibers, synthetic rubber and other polymers as raw materials. Through various processing processes, different shapes and structures are made, such as plane-like geotextile, film-like geomembrane, mesh geoglyph and other types. With the continuous expansion of the scope of use, the production and application technology of geosynthetic materials is also improving rapidly, so that it gradually forms a new marginal subject.
² The situation of geosynthetic materials in our country
1. Applications began in the 1960s
2. Geotextile has been used for bank protection, flood prevention and prevention since 1976
3. In 1995, "China Geosynthetic Materials Engineering Association" was established
4. In 2002, China's geosynthetic materials application workers won the special award issued by the International Society of Geosynthetic Materials (IGS)
5. In 1998, China broke out a huge flood, and geosynthetic materials played a good role in flood resistance. The central leadership attaches great importance to it, which promotes the normalization and popularization of geosynthetic materials
² Types, functions and characteristics of raw materials for geosynthetics
| Name | Speciality |
| PE | Good flexibility, ductility, transparency, cold resistance, processability |
| PP | Heat resistance, chemical stability, good electrical insulation, light resistance, poor toughness |
| PVC | High strength, wear resistance, flame retardant, poor thermal stability, easy aging |
| PET | Thermoplastic is the best in strength and toughness, good light transmittance, acid resistance, alkali resistance, soluble in ammonia |
| PA | Synthetic fibers have the highest strength, wear resistance, non-flammable, alkali resistance and acid resistance |
| PS | Chemical corrosion resistance, water resistance and electrical insulation is good, heat resistance and easy aging |
| CR | Oil resistance, acid and alkali resistance, high tensile strength and air tightness, poor storage stability |
Classification of geosynthetic materials
1. Geotextiles: spun geotextiles, such as warp knitted geotextiles, can be manufactured by needle bonding, heat bonding, adhesive bonding and other methods. Often referred to as geotextiles, it is one of the most commonly used geosynthetic materials.
2. Geomembrane: It can be manufactured by blow molding extrusion, calendering, coating and other methods, and the film material is PE, HDPE, PVC and so on. Including pure membrane and composite geomembrane.
3. Geocomposite materials: including composite geotextile, composite geomembrane and composite prevention and drainage materials.
4. Other materials:
Geoglage (warp knitted grating), geoband, geoband, geoband, geoband, geoband, etc.
Geosynthetic materials bentonite liner (GCL), three-dimensional vegetation mesh mat, polystyrene plate, foam geomaterials, etc.
² The role of geosynthetics
l Geotextiles have the following important functions:
1. 1 filtration: prevent the loss of soil particles,In hydraulic engineering, when water flows through the soil, the geotextile can be placed between the drainage water and the soil to play a filtering role.
2. the drainage effect：Rapid removal of water in the soil: geotextile has good permeability, can form a drainage channel in the soil, and quickly remove water in the soil
3. isolation effect: prevent different materials from mixing with each other，In engineering, geotextiles can isolate materials of different properties.
4. reinforcement effect: enhance the tensile strength of soil，Geotextile has a certain tensile strength, when the pawnshop is set in the soil, it can jointly bear the external force with the soil and enhance the tensile strength of the soil.
l Geomembrane have the following important functions:
1. Anti-seepage effect: Geomembrane is an important anti-seepage material in hydraulic engineering. Geomembrane can withstand water pressure, prevent water penetration through the soil, and protect the surrounding soil and ecological environment. Geomembrane plays a key role in preventing seepage in landfill sites. It can prevent landfill leachate from seeping into the ground and contaminating soil and groundwater.
2. the isolation effect: Geomembranes can isolate media with different properties, preventing them from mixing with each other or producing chemical reactions. In some special industrial sites, geomembranes can isolate different chemicals and avoid adverse reactions between them. Protective infrastructure.In some projects, geomembranes can be used to protect the infrastructure from external factors.
l Geocomposite materials have the following important functions:
1. comprehensive performance advantages: both a variety of functions: Geocomposites combine the advantages of different geosynthetic materials and have a variety of functions. For example, the composite of geotextile and geomembrane can play the role of filtration, drainage and reinforcement of geotextile and the seepage prevention of geomembrane at the same time. The combination of geograe and geotextile can not only enhance the bearing capacity of soil by using the high strength of geograe, but also improve the overall performance of the project by using the filtration and drainage functions of geotextile.
2. Adapt to complex engineering environment: Responding to different engineering needs: In some complex engineering environments, a single geosynthetic material may not meet the engineering requirements, while geocomposite materials can be customized according to the specific situation. Geocomposite materials can be combined with geomembrane, geomesh, geotextile and other materials to form a comprehensive sealing system to meet the various needs of landfill sites. Geocomposite materials can be combined with geogrids, three-dimensional geogrids and other materials, which can not only enhance the anti-sliding ability of the slope, but also effectively drain water to prevent the erosion of the slope by rain.
3. improve engineering quality and durability: Enhance engineering stability, geocomposite materials through the synergistic effect of different materials, can improve the stability of the project. In hydraulic engineering, geocomposite materials can resist the erosion and erosion of water flow and extend the service life of the project.
4. environmental protection: to prevent the spread of pollution, in some projects with high environmental requirements, geocomposite materials can play a role in preventing the spread of pollution. Promote ecological restoration. In some ecological engineering, geocomposite materials can provide good conditions for vegetation growth.
² Summarize：
Geosynthetic materials are the general term for synthetic materials used in civil engineering, using synthetic polymers such as plastics, chemical fibers, synthetic rubber, etc. as raw materials to make various products, placed inside the soil, on the surface or between various soils, to strengthen or protect the soil. In the future, with the continuous advancement of global infrastructure construction, including the continuous development of transportation, water conservancy, energy and other fields, the demand for geosynthetic materials will maintain stable growth. For example, under the "Belt and Road" initiative, there are many infrastructure construction projects in countries along the route, providing a broad market space for geosynthetic materials. Countries in the field of geosynthetics technology and application experience are different, through international cooperation and exchange, can promote technology sharing, complementary advantages, and promote the common progress of the global geosynthetics industry. Domestic enterprises will also have more opportunities to participate in international market competition, expand overseas business, and enhance the international influence of China's geosynthetic materials industry.
