Navi Mumbai, Maharashtra, India | JNPT & CIDCO
Jawaharlal Nehru Port Trust (JNPT), India’s premier container port, allocated 111 hectares of land at Dronagiri for resettlement and infrastructure development for project-affected persons from 12 villages impacted by port expansion.
At the eastern boundary of the 12.5% scheme in Dronagiri, an existing channel spans approximately 1.5 km. This channel requires proper channelization to effectively manage the given water discharge while ensuring slope stability and preventing soil erosion.
The initial proposal suggested shaping the channel as per the designated cross-section and lining it with cement mortar. However, this approach presents significant technical challenges due to the marshy characteristics of the in-situ soil. Marshy soils are highly compressible and prone to differential settlements, which can cause rigid lining systems, such as cement mortar, to develop cracks. These cracks compromise the structural integrity of the lining, leading to progressive failure over time. Additionally, the impermeable nature of mortar lining can trap pore water, resulting in increased pore pressure that further destabilizes the channel. Hence, the channel needs to be lined with such a system which shall be flexible and porous in nature such that it can absorb differential undulations and prevent development of pore water pressure and exert a very light pressure on the weak insitu foundation soil.
To address the challenges of this channel lining project, TechFab India proposed using TechFab Metal Gabion Mattresses as an alternative to mortar lining. We offered 0.3m thick gabion mattresses (10×12, Wire Dia. 2.7mm / 3.7mm, 90% Zinc+ 10% Al + PVC Coated) made of steel wire mesh filled with stones, providing a flexible and durable solution capable of withstanding soil settlement and water flow variations. Additionally, TechGeo nonwoven geotextiles, made from high-quality polypropylene staple fibers, were placed beneath the gabion mattresses to provide separation, filtration, and drainage functions, ensuring long-term durability and performance.
Due to the marshy nature of the soil and the loose topsoil at the channel bed, a 2m thick boulder filling layer was recommended before placing the gabion mattresses. This boulder layer, spanning a total width of 20m, provided a stable base for the side slopes of the channel, enhanced the bearing capacity of the foundation soil, and minimized settlements. Additionally, the design considered a traffic loading of 24 kPa on the crest of the channel, ensuring safe execution and long-term functionality.
The project was successfully completed, demonstrating the advantages of using TechFab Metal Gabion Mattresses over traditional cement mortar lining. This solution ensured durability, flexibility, and sustainability, addressing settlement issues while enhancing environmental integration. The project highlights TechFab India’s commitment to innovative, cost-effective, and long-lasting geosynthetic solutions for infrastructure development.
