Erosion Control for Green Highway Construction
Namrata Bichewar, Regional Manager - Maharashtra, Gabion Technologies India Pvt Ltd, discusses the company’s contribution in constructing green highways using Bio-Engineering Erosion Control methods and solutions.
The government plans to construct 26 green expressways in the next three years, as announced by road transport & highway minister Nitin Gadkari. He also stated that India’s road network will be as good as that of the US by 2024. Green highway is defined as a road that is planned and designed based on a (relatively new) concept that integrates transportation functionality and ecological sustainability. Green highway will emphasise the environmental approach towards the transportation system development, ecosystem, urban growth, public health, and surrounding communities.
It is important to note that the effort of greening the highway will require an understanding of how the highway is configured and governed. The aim is to reduce the impact of air pollution and dust by planting trees and shrubs along the National Highways. The trees will act as natural sinks for air pollutants and arrest soil erosion at the embankment slopes.
“Green techniques include the maximum use of local materials, stabilisation of soils to reduce the need for crushed stones, use of waste products such as fly ash, recycling asphalt and granular pavements, bio-engineering solutions, water conservation and harvesting techniques, designing for resilience to climate change impacts, and solar lighting,” as stated by a World Bank spokesperson. Professionals interested in natural restoration of landscapes will find bioengineering techniques useful.
Soil / Slope Erosion
Soil erosion occurs whenever water meets land with enough force to move soil. This often occurs along embankment slopes or mountainous slopes in roads and stream river banks, or where excess water flows over hill slopes. While hill slope erosion can be dramatic, especially after heavy rainfalls or floods, normal stream flows, excess runoff from urbanized areas, and rain action along a hill slope will continually erode the soil. In many cases, traditional erosion control methods are expensive, ineffective, or socially unacceptable. As an alternative solution (as per IRC 56-2011), bioengineering is recommended for erosion control.
Bioengineering for Erosion Control
Bioengineering is a method of construction using live plants alone or combined with dead or inorganic materials (geosynthetics), to produce living, functioning systems to prevent erosion, control sediment, and provide habitat.
Bioengineering involves the use of live plants to add structural strength to soil. The solutions can be adopted for soil stabilization and erosion control situations from stream banks, river scours, and roadside slopes for protection to upland gully restoration and slope stabilization. Bioengineered restoration of flood or high-water damage to streams and roads provide a more natural-looking solution than traditional concrete structures.
Advantages of bioengineering solutions
- Low cost and lower long-term maintenance cost than traditional methods
- Low maintenance requirement of live plants after they are established
- Environmental benefits of wildlife habitat, water quality improvement, and aesthetics
- Improved strength over time as root systems develop and increase structural stability
- Compatibility with environmentally sensitive sites with limited access.
Gabion Technology India offers Design, Supply and Execution for the following Bioengineering Erosion Control Methods:
- Hedge Brush layer
- Bamboo Plantation
- Hydroseeding /Mulching
- Geocell with Hydroseeding
- Coco Fibre /Jute Erosion Control Blanket with Grass Plantation
- Double Twisted Wire Mesh netting with Grass Strips / Hydroseeding
- Shotcrete Crib Wall with Vegetation (Japanese Technology).
NBM&CW October 2022
