In various engineering construction projects, there is a kind of material that, although not often in the spotlight of the public, plays a vital role. That is geotextiles.
I. Overview of Geotextiles
Geotextiles, also known as geotextile fabrics, are water-permeable geosynthetic materials made by needling or weaving synthetic fibers. They possess excellent physical properties and chemical stability and can function under various complex environmental conditions.
There are numerous types of geotextiles. According to different manufacturing processes and uses, they can be divided into non-woven geotextiles and woven geotextiles. Non-woven geotextiles are made by randomly arranging fibers and needling them together, having good filtration, separation, and drainage properties. Woven geotextiles are formed by interweaving warp and weft threads, with relatively high strength, and are suitable for reinforcement and protection engineering.
II. Application Scope of Geotextiles
Road Engineering
In road subgrades, geotextiles can play a separation role, preventing the mixing of soil materials of different particle sizes and maintaining the stability of the subgrade. For example, when constructing a new road, laying geotextiles between the soil foundation and the subgrade can effectively prevent the fine-grained soil in the soil foundation from entering the subgrade and affecting the strength and stability of the subgrade.
Geotextiles can also be used in the reinforcement engineering of roads. When building roads on soft soil foundations, due to insufficient bearing capacity of the foundation, it is easy to cause road settlement and cracking. At this time, laying geotextiles in the foundation can increase the tensile strength of the foundation and reduce settlement and uneven settlement. For example, in the widening projects of expressways, geotextiles are often used to strengthen the joint parts of the new and old roadbeds to prevent uneven settlement of the new and old roadbeds.
In addition, geotextiles have good drainage properties. In the drainage system of roads, geotextiles can be used as a filter layer to prevent drainage pipes from being blocked and ensure the smooth operation of the drainage system.
Water Conservancy Engineering
In embankment projects, geotextiles are one of the indispensable materials. They can be used for filtration and drainage of embankments, preventing the soil particles in the embankments from being washed away by water flow. Meanwhile, they can ensure that the moisture inside the embankments can be discharged in a timely manner, reduce the saturation line of the embankments, and improve the stability of the embankments. For example, in the construction of earth-rock dams, a layer of geotextiles is usually laid between the dam body and the dam foundation as a filter layer to prevent the loss of soil particles in the dam body.
Anti-seepage of canals is also an important application area of geotextiles. In irrigation canals and water conveyance canals, due to the long-term scouring and infiltration of water flow, it is easy to cause canal leakage and damage. Laying geotextiles can effectively reduce the leakage loss of canals and improve the utilization efficiency of water resources. Meanwhile, geotextiles can also protect the lining structures of canals and extend the service life of canals.
Geotextiles can also be used in the anti-seepage projects of reservoirs. Laying geotextiles on the dam body, reservoir bottom, and slopes of reservoirs can effectively prevent water leakage in reservoirs and ensure the safe operation of reservoirs.
Environmental Protection Engineering
Landfills are one of the important application sites of geotextiles. In landfills, geotextiles can be used for the isolation, anti-seepage, and drainage of garbage. They can prevent harmful substances in the garbage from permeating into the soil and groundwater, causing environmental pollution. Meanwhile, geotextiles can also collect landfill leachate and guide it to sewage treatment facilities for treatment. For example, in modern landfills, multiple layers of geotextiles are usually laid between the garbage layer and the soil to form a complete anti-seepage system.
The construction of sewage treatment plants also cannot do without geotextiles. In the pools, aeration tanks, and sedimentation tanks of sewage treatment plants, geotextiles can be used as anti-seepage layers and filter layers to prevent sewage leakage and sludge loss. Meanwhile, geotextiles can also be used for sludge dewatering in sewage treatment plants to improve the dewatering efficiency of sludge.
Railway Engineering
In railway subgrades, geotextiles can play the roles of separation, reinforcement, and drainage. They can prevent the soil particles in the subgrades from being taken away by train vibration and water flow, and at the same time increase the strength and stability of the subgrades. For example, in the construction of high-speed railways, in order to ensure the smooth operation of trains and the stability of subgrades, geotextiles are usually laid in the subgrades.
In railway tunnel engineering, geotextiles can be used for waterproofing and drainage of tunnels. They can prevent groundwater from permeating into the interior of tunnels and affecting the safety of tunnel use. Meanwhile, geotextiles can also collect the seepage water in tunnels and guide it to the drainage system for discharge.
Mining Engineering
During the mining process, geotextiles can be used for the protection and drainage of mine slopes. They can prevent slope collapse and soil erosion, and at the same time ensure the safe production of mines. For example, in the mining of open-pit mines, geotextiles are usually laid on the slopes and vegetation is planted to achieve the purposes of protection and greening.
The construction of mine tailing ponds also requires geotextiles. Geotextiles can be used for the anti-seepage and drainage of tailing ponds to prevent harmful substances in the tailings from permeating into the soil and groundwater, causing environmental pollution.
III. Advantages of Geotextiles
Good Physical Properties
Geotextiles have relatively high strength and durability and can withstand relatively large tensile and compressive forces. In engineering applications, they can effectively enhance the tensile strength and stability of soil masses, preventing soil deformation and destruction.
Geotextiles have good water permeability, which can enable the moisture in soil masses to be discharged in a timely manner, reduce the water content of soil masses, and improve the stability of soil masses. Meanwhile, they can also prevent water flow from scouring the soil surface and protect the surface of soil masses.
Good Chemical Stability
Geotextiles have good chemical stability and can resist the erosion of chemical substances such as acids, alkalis, and salts. Under various harsh environmental conditions, they can maintain stable performance and will not undergo degradation and aging.
Convenient Construction
Geotextiles are lightweight and convenient for handling and laying. They can be cut and spliced according to engineering needs. The construction is simple and fast, which can greatly shorten the project cycle.
Environmental Protection and Energy Saving
Geotextiles are an environmentally friendly material. They can be recycled and will not cause pollution to the environment. Meanwhile, they can reduce the amount of earth excavation and filling in engineering construction, reduce engineering costs, and save resources.
