Patent ID: 9359725
Filing Date: 2016-06-07
CPC Classification: E01C,E02D,E21D

Claim Text:
1. A process for making an underpass through a railway track or road without service interruption by stepwise destabilization and stabilization of a collapsible soil mass by a soil nailing technique, the process comprising the steps of: (i) marking a position of a box on a vertical face of a first retaining wall or an embankment; (ii) dismantling the retaining wall above the marked position of the box and providing temporary support by shuttering plates having holes for pre-decided positions of nails to be driven in the vertical face; (iii) nailing the soil mass by using grouted nails and driven nails above the marked position of the box; (iv) again dismantling the first retaining wall, placing the shuttering plates with pre-drilled positions of nails and inserting only the driven nails from the top to the bottom of a box pushing area; (v) leaving a complete nail system for a period in the range of 8 to 12 hrs to mobilize the friction of the nails; (vi) bringing the box close to the soil-nailed, wall face; (vii) loosening one top row of shuttering plates, and excavating the soil to a 30 to 40 cm depth; (viii) repeating step (vii) until the entire rows of the nails are covered for a 30 to 40 cm depth followed by pushing the box into the excavated area of 30 to 40 cm depth; (ix) pushing the nails into the soil mass and again tightening of the shuttering plates; (x) repeating steps (vii) to (ix) until 50% of the box pushing length; (xi) cutting the nails in the range of 25 to 35 cm to create a space for box pushing wherein first/pointed ends of the nails will touch a second retaining wall, followed by placing vertical nails in order to increase the stability of the cut slope; and (xii) again repeating steps (vii) to (ix) until complete insertion of the box for making an underpass.