JNPT, Navi Mumbai, Maharashtra, India | Oil Field Warehouse & Services Private Limited
The site is located in JNPT, Uran, Navi Mumbai, where the presence of deep soft clayey deposits is very common. The soft clayey deposits have very low bearing capacity, shallow water table and become slushy during monsoons. The client wants to build a warehouse and a container yard where there will be heavy movement of large ridge stackers and constant dead load of containers in 4 stacking arrangement. This needs improvement in soil bearing capacity to sustain heavy machinery traffic and dead loads.
Conventionally, such site would require huge soil replacement and a very thick concrete pavement. This solution could be very uneconomical and time consuming, therefore in order to find a low cost solution for the soft soil deposits and improvement the bearing capacity, the consultant approached TechFab India to propose a solution.
In order to enhance the soil subgrade conditions, provide a firm support to the top pavement layer which could sustain heavy loading and reduce bearing pressure on the low bearing strata, it was decided to reinforce the subgrade soil with TechCell Geocell and TechGrid PP Biaxial geogrid.
Based on the information provided by the client, ground improvement is suggested using TechCell geocells. TechCell of pocket size 356mm and depth 150mm was proposed according to IS 17483 – Part 1.
The TechCell geocell filled with GSB or non-cohesive coarse angular material will help in reducing the pressure on the subgrade thereby minimizing differential settlement due to the induced pressure and providing basal support to the slab. TechCell will improve the modulus of marginal fill material and transfer the load pressure to wider area and hence reduces the strains to permissible limits.
In addition to TechCell Geocell, TechGrid PP3030 Biaxial Geogrid and Non-woven Geotextile PR25 was also used below the Geocell layers to act as a separation and filter layer. PP3030 will provide additional basal reinforcement and counter the radial stresses generated due to tyre movement of ridge stacker and heavy tractor trailers, while Non woven geotextile PR25 will provide a separation layer between the fine soil of the soft ground and the infill material and prevent the intermixing. It will also help in preventing the erosion of fines from the either layers.
Furthermore, it was suggested that the client could use paver blocks as the top layer which are easier to install, maintain and come at a lower cost as compared to concrete pavement.
The work is completed by contractor and presently the in excellent condition after one monsoon and the client is satisfied with the performance of TechCell Geocell, TechGrid PP Biaxial Geogrid and Techgeo Nonwoven Geotextile.
