Geosynthetics are versatile materials that can be used in a variety of applications in tunnel construction. One of the most common uses of geosynthetics in tunnel construction is as a filter and separator. This involves placing geotextiles between layers of soil to prevent the mixing of different soil types and to allow water to pass through. Nonwoven and woven geotextiles are effective in this application because they are able to filter out fine particles while allowing water to pass through.
Geotextiles for tunnels
Geosynthetics are also used in tunnel construction as drainage layer. It is placed on top of the soil and under the concrete or asphalt layers to enhance the water drainage, which prevents water from seeping into the tunnel and causing damage.
Another application of geosynthetics in tunnel construction is as a waterproofing layer. Geosynthetics can be used to create a barrier that prevents water from penetrating into the tunnel. This can be especially important in areas where the soil is prone to high water table or heavy rainfall.
In addition, nonwoven geotextiles can be used as a protection layer for the primary lining of the tunnel. They are placed on top of the primary lining to protect it from mechanical damage and also to reduce wear and tear. Thick, heavy duty nonwoven geotextiles will also act as a drainage layer when used as protection.
For bored tunnel construction, where risks of fire need to minimized to guarantee a safe work environment, special fire resistant geotextiles should be used as protection layer.
Overall, geotextiles are a valuable tool in tunnel construction because they can improve the stability and performance of the tunnel, while also reducing maintenance and repair costs. They can be used in a variety of ways, including as a filter and separator, drainage layer, waterproofing layer and a protection layer, to enhance the safety and longevity of the tunnel.