TOP DOWN CONSTRUCTION ADVANTAGES

BySai Towers P Ltd.

Why Top Down Construction Required

• Distance between Boundary wall of Adjacent Existing Building and Building Line for New Building is too close and the depth of excavation is more than 6 meter and possibility of collapse the soil is higher during excavation.

• Using Top Down Construction more Building and Basement Area can use. Suitable for two or more basement.

• The first base slab level slab will act in such area as a strut member and the Retaining wall panels will not allow collapse of soil.

• Water table is too high and difficult to cast Retaining wall, Diaphragm wall or Continuous Pile can use as a Retaining wall.

METHODOLOGY OF TOP DOWN CONSTRUCTION

• Setting out for alignment of bore cast in situ of piles .

• Bore Cast in Situ Piles to be cast and dowels bar to be kept for Retaining wall panels. The center of piles and Retaining wall panels center line to be kept in same line. The Diameter of Piles preferred 600 mm, distance between two piles center to center preferred 3.33 meters (Suit for C/C distance of Columns), Depth of Piles to be confirmed by Structural Consultants.

• Touching Piles can use as a Retaining wall with supporting arrangement during Excavation.

• Water table is too high and difficult to cast Retaining wall, Diaphragm wall or Continuous Pile can use as a Retaining wall.

• Instead of Column C1 to Column C8,Bore cast in Situ piles to be cast with dowel bars for different level slab and connecting Beams, The Diameter of Piles (suit as per Columns size), Reinforcement details (with dowels for Retaining wall and different level slabs and Beam), Depth of Piles to be confirmed by Structural Consultants.

• Excavation to be done around 2 meter depth and retaining wall panels to be cast in stages with dowels bars with adjacent piles and dowel bars for next Retaining wall panel to be kept .if soil between piles collapsed soil nails with wire mesh to be kept on earth side to retain the same. Retaining wall panels to be cast with dowels up to the first base slab bottom.

• Dressing and compaction of soil to be done for PCC bed for casting of first base slab. 50mm PCC (M15 Grade) to be done, the top levels of PCC to be keep the base slab level bottom. For beams excavation to be done in same alignment and dimensions as required and PCC or brick work to be done as per beam dimensions in Vertical face.

• After PCC 3mm ply to be laid on PCC Surface and PVC sheet to be nailed with PCC surface so surface of PCC and Surface of Slab Concrete will separate. 7. Reinforcement to be completed as per drawings, for beams dowel bar to be used from Cast in Situ Piles. Dowel bars to be keep for adjacent slabs for Bottom Up Construction.

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• Concreting of Slab and Beam to be completed.

• After 14 days of Concreting, PCC below slab to be break/removed excavation to be continued and retaining wall panels to be cast. Till final level of excavation.

• Waterproofing to be done and base slab to be cast with dowels from Cast in Situ Piles.

• Jacketing of Columns to be done if required

If any query please mail – saitowers2000@gmail.com or visit - sai-towers.com