Drainage geotextile
Short Description:
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- Drainage geotextile is a kind of geosynthetic material, which is mainly used in the drainage systems of civil engineering and geotechnical engineering. It can effectively drain water from the soil and also play a role of filtration and isolation. It’s a multi – functional engineering material.
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- Drainage geotextile is a kind of geosynthetic material, which is mainly used in the drainage systems of civil engineering and geotechnical engineering. It can effectively drain water from the soil and also play a role of filtration and isolation. It’s a multi – functional engineering material.
- Drainage Principle
- The drainage of drainage geotextile is mainly based on its pore structure and permeability. There are many tiny pores inside it, and these pores are interconnected to form a complex network of drainage channels.
- When there is water in the soil, under the influence of gravity or pressure difference (such as hydrostatic pressure, seepage pressure, etc.), the water will enter the interior of the geotextile through the pores of the geotextile. Then, the water flows along the drainage channels inside the geotextile and is finally guided to the outlet of the drainage system, such as drainage pipes, drainage troughs, etc.
- For example, in the subgrade drainage system, the groundwater enters the drainage geotextile under the action of pressure difference, and then the water is transported to the roadside drainage pipes through the geotextile, thus realizing the drainage of the subgrade.
- Performance Characteristics
- Drainage Performance
- Drainage geotextile has a relatively high water permeability rate and can quickly drain water. Its water permeability rate is usually measured by the permeability coefficient. The larger the permeability coefficient, the faster the drainage speed. Generally speaking, the permeability coefficient of drainage geotextile can reach the order of magnitude of 10⁻² - 10⁻³ cm/s, which enables it to effectively meet different drainage requirements.
- It can also maintain good drainage performance under a certain degree of pressure. For example, when the road subgrade is under the vehicle load, the drainage geotextile can still drain normally and will not block the drainage channels due to pressure.
- Filtration Performance
- While draining, the drainage geotextile can effectively filter soil particles. It can block the fine particles (such as silt, clay, etc.) in the soil from entering the drainage channels and prevent the drainage system from clogging. Its filtration performance is realized by controlling the pore size and pore structure of the geotextile.
- Generally, the equivalent pore size (O₉₅) is used to measure the filtration performance of the geotextile. This parameter represents the maximum value of 95% of the particle diameter that can pass through the geotextile. The appropriate equivalent pore size can ensure that only water and substances dissolved in water can pass through, while the soil particles are intercepted.
- Mechanical Properties
- Drainage geotextile has a certain tensile strength and tear strength and can withstand the tensile and tear effects during the construction process. The tensile strength is generally in the range of 1 - 10 kN/m, which makes it not easily broken during the laying and use process.
- It also has good anti - puncture performance and can resist puncture when encountering sharp objects (such as stones, roots, etc.) and avoid the destruction of the drainage channels.
- Durability and Corrosion Resistance
- Since drainage geotextile is often exposed to various environmental conditions, it has good durability. Under the influence of ultraviolet irradiation, temperature change, chemical substance erosion and other factors, it can still maintain its performance.
- It has a good tolerance to chemical substances such as acid and alkali, and can work normally whether in acidic soil or alkaline soil. For example, in the underground drainage system of a chemical industrial park, the drainage geotextile can resist the erosion of chemical wastewater and ensure the normal operation of the drainage system.
- Drainage Performance
- Application Scenarios
- Road and Railway Engineering
- In terms of subgrade drainage, drainage geotextile can be laid at the bottom or on the slope of the subgrade to drain groundwater and surface water of the road. This helps to prevent the subgrade from diseases caused by water accumulation, such as frost heaving and subsidence.
- In the retaining wall engineering of roads and railways, drainage geotextile can be used as a filter layer and installed at the back of the retaining wall to drain the water behind the wall and prevent the loss of soil particles, ensuring the stability of the retaining wall.
- Water Conservancy Engineering
- In the internal drainage systems of water - conservancy buildings such as dams and dikes, drainage geotextile can be used to drain the seepage water inside the dam body or dike body, reduce the pore - water pressure and improve the stability of the structure.
- In the river - bank slope - protection engineering, drainage geotextile can be used as a drainage and filter material to drain the water accumulated in the slope body and prevent the soil of the slope body from being washed away by the river water.
- Construction Engineering
- In the waterproof and drainage systems of building basements, drainage geotextile can be used as an auxiliary drainage material in combination with the waterproof layer. It can drain the groundwater around the basement and prevent the basement from getting damp and flooded.
- In the foundation drainage engineering, drainage geotextile can be laid at the bottom of the foundation to drain the water under the foundation and improve the stress environment of the foundation.
- Landfill Engineering
- At the bottom and slopes of landfills, drainage geotextile can be used to collect and drain the leachate generated by garbage decomposition. This is of great significance for preventing leachate leakage and protecting the environment.
- It can also be used in combination with other geotechnical materials (such as geomembranes) to construct a composite drainage and anti - seepage system for landfills.
- Road and Railway Engineering
| 参数（Parameters） | 单位（Units） | 描述（Description） |
|---|---|---|
| 渗透系数（Permeability Coefficient） | cm/s | 衡量排水土工布透水能力的指标，反映水在土工布中流动的难易程度。 |
| 等效孔径（Equivalent Pore Size，O₉₅） | mm | 表示能通过土工布的颗粒直径的 95% 的最大值，用于评估过滤性能。 |
| 拉伸强度（Tensile Strength） | kN/m | 土工布在拉伸方向上能够承受的最大拉力，体现其抵抗拉伸破坏的能力。 |
| 撕裂强度（Tear Strength） | N | 土工布抵抗撕裂的能力。 |
| 抗穿刺强度（Puncture Resistance） | N | 土工布抵抗尖锐物体穿刺的能力。 |
