Drilled Expanded Base Cast-in-Place Concrete (Belled or Caisson) Piles

Maximum Capacity, Minimal Cost

Expanded base (belled) concrete piles are another form of drilled, cast-in-place concrete pile similar to friction piles with the exception of works completed at the termination depth with our specialty belling tools to enlarge the base of the pile to offer greater capacity. This pile type is the cost effective solution when the soil stratigraphy allows for very high bearing pressures in soils suitable for drilled cast-in-place piles. The geometry of the pile itself offers inherently higher capacity and better frost uplift resistance than friction piles because of the expanded base, and these piles are typically selected when the loading is moderate to severe with lighter loaded piles on friction or helical piles. These piles are typically installed to a maximum diameter of 3 times the shaft diameter, and are always installed with a geotechnical representative on site to confirm the bearing capacity of the termination depth soils. These pile sizes range from shaft diameters of 406mm to 1220mm and expanded base sizes of 1220mm to 3660mm, with depth varying based on the soils, but typically less than 12m in length.

The Prairie’s Belled Pile Experts

Innovative Piling offers the largest selection of piling rigs and belling tools available in the province for this pile type, having installed full bell diameters on cased shaft sizes up to 1220mm (3.66m bell diameter) and 15.2m in depth. Our wide variety of equipment offers us the ability to engineer our belled pile designs to suit maximum productivity and minimal cost-risk to the client, with project consideration at the forefront of this stage. With the ability to handle point loads up to 4500 kN, IPS’ expanded base division has designed and implemented a multitude of combinations of belled pile options for our clients saving cost and schedule.

From Start to Finish

  1. Installation crew will complete a pre-construction site evaluation and Jobsite Safety Analysis
  2. Offsets are placed on original pile location
  3. Drilling rig is spotted into position
  4. Drilling rig level and alignment is double checked
  5. Work area cleared and drilling commences, safety barricades constructed
  6. Level and alignment periodically checked during drilling
  7. Upon reaching termination depth, final pile length including cutoff elevation is checked
  8. Belling tool is prepared, and expanded to desired base width and marked to check openness of tool
  9. Belling commences, and kelly bar marks indicate approximate width of base
  10. Using safe, designated zone; after each hole reaming, the tool is spun off to remove tailings
  11. Upon completion, belling tool is packed and dry run down the hole to gain accurate width of base
  12. Geotechnical inspector confirms adherence to specifications and design parameters
  13. Reinforcing steel is rigged and hoisted into place along the depth of the pile
  14. Concrete is poured down the centre of the shaft until reaching desired elevation
  15. Drilling tailings cleaned up and neatly stockpiled on site for removal

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