Ground improvement of marine clay for highway construction in mumbai, India.

Abstract

Ground improvement of marine clays is the most inventive field of geotechnical engineering. Various techniques such as use of prefabricated vertical drains (PVDs), vacuum consolidation, stone columns, etc., are available for improving the mechanical and engineering properties of the marine clays. In the present paper, the use of PVDs with preload for improving the soft marine clay that support the sub grade of state highway No. 54 from Panvel to Uran at Mumbai, India is studied. The 3.25 km stretch of marine clay was present up to a depth of 12–15 m. As the road connects to the Jawaharlal Nehru Port (India’s major hub port) road, heavy traffic is expected to be moving through this road. Staged embankment construction of 4.30 m height with PVDs was employed to sustain the heavy vehicular traffic load and to reduce the post-construction settlement. A total of 650 thousand running meter PVDs were installed at a spacing of 1.20 m. The 4.30 m high preload was kept in stages for a period of 6 months. Various instruments were installed to monitor the pore water pressure, settlement, and lateral displacements. The substantial settlement of 636 mm was achieved during this period.