Le, Maharashtra, India | Nodal Executive Engineer, PMGSY MMRDA, Dhule, Maharashtra
Shirpur is a taluka in Dhule district of Nashik Division, 50 km from the city of Dhule. The road stretches which was to be upgraded was passing through agricultural fields of cotton and banana having very low subgrade CBR of 1.67%, which was causing continuous seepage of water through the crust of road. And the road was subjected to heavy sand traffic of Hyva Trucks which were coming from Tapi River.
Due to these reasons the existing road was damaged in the form of major settlement, cracks, unevenness resulting overall damage to WBM layer. The road laid on black cotton soil (BC Soil) bases develop undulations at the road surface due to loss of strength of the subgrade through softening. Black cotton soil contains montmorillonite mineral, because of which the soil becomes very slushy when in contact with water and gets brittle on drying. These alternate cycles of wetting and drying makes the highly unsuitable for any type of construction. Flexible pavement designed over this type of soil requires very high crust thickness, which makes it uneconomical. Considering the existing pavement condition and heavy traffic loading it was decided by the Client to go for pavement rehabilitation solution that is durable.
The Client referred the problem to TechFab India Industries Ltd. for the upgradation of the existing road. Ease and speed of construction was a key element in the design selection process. Considering the site condition and poor soil properties, we suggested the use of TFI – 5300 Type-I as per guidelines of IRC:SP:59-2002 for the subgrade stabilization and TechGrid Biaxial Geogrid TGB-40 (40mm x 40mm) for the reinforcement of granular materials of the existing road stretches comprising of black cotton soil, high traffic intensity & water logging.
The project was successfully completed in March 2017 within the stipulated time following all the quality norms and as of June 2021, the road stretch is performing well as desired.
The rural road passed through agricultural fields with very weak subgrade soil (CBR of 1.67%). Continuous water seepage and heavy truck traffic from the Tapi River caused severe settlement, cracks, and unevenness, damaging the existing pavement.
Black cotton soil contains montmorillonite mineral, which becomes slushy when wet and brittle when dry. These cycles of wetting and drying make it highly unsuitable for road construction, requiring very thick pavement crusts that are uneconomical.
TechFab India recommended:
This combination improved soil strength, controlled deformation, and enhanced pavement durability.
Completed in March 2017, the upgraded road has been performing well under heavy traffic and adverse soil conditions. As of June 2021, the pavement continues to deliver the desired performance with minimal maintenance.
By applying geosynthetics to rehabilitate rural roads on problematic black cotton soil, TechFab India demonstrated its ability to deliver cost‑effective, durable, and innovative solutions aligned with PMGSY standards.
