Mass Gravity Retaining Walls
BANGALORE - KARNATAKA - India
Promont Hilltop Pvt. Ltd (a subsidiary of Tata Housing Development Company)
SLOPE RETENTION -ACCESS RAMP WALL OF ‘THE PROMONT’ HOUSING PROJECT
Figure-2 Access Ramp-During construction
Figure-3 Access Ramp-During construction-compaction
Figure-4 Access Ramp-After completion of works
Figure-5 Access Ramp-After completion of works
Figure-6 Access Ramp-After completion of works
‘The Promont’ housing complex has been planned over a hilltop in Banashankari Stage III area of Bangalore. The hill slope strata is of predominantly rock (Granite). However, at certain locations, highly weathered Charnockite is also present making slope stabilization works essential. Various stabilization/retention structures namely, Top wall, Bottom wall, Access Ramp retaining wall, wall near CDP road etc are constructed as a part of external works of project. The vertical cut height for access ramp varies from 4.5m to 14m.
The solution comprised of Gabion retaining wall (Height – 4.5m to 14.0m) (with base and /or lateral anchoring) with surcharge soil slope of max. 30 deg slope above the wall with dry stone pitching/erosion control mats. Gabion retaining wall had units of width 2-4m. The Gabion facia units had H-frame arrangement at the rear end for lateral nails. The lateral nails (HYSD bars of 25mm dia) are of approx. 2m long and vertical nails (HYSD -25mm dia) at base are of approx. 1.5m long spaced at 1m c/c. Paralink layers were used in isolated locations for additional strengthening. The design of nails and design of Gabion retaining wall are done with SLIDE and MacSTARS software respectively. Top 1m high planter units (Gabion units lined with non woven geotextile and BioMac filled with soil on top two-third of the height) were installed throughout the stretch length for vegetation (in consultation with local horticulturist). Suitable drainage measures were additionally adopted.