Deep foundations where high concentrated loads are to be supported with low settlements.
On sites with poor near surface ground strata concentrated structural loads, such as below columns, tower cores or load bearing walls, often require deep foundations to ensure acceptable total and differential settlements. Piles are generally required to resist significant compression (downward) loads with low settlements by transferring the load to deeper higher strength founding strata. Tower cores frequently impose significant overturning moments under seismic conditions and can induce tension (uplift) and lateral loads in piles in some load cases.
Commonly adopted pile types include the following;
- Driven piles – steel tube, steel UC, precast concrete, timber.
- Driven cast in place.
- Hydraulically “pushed in” piles – precast concrete.
- Continuous flight auger (CFA) piles.
- Screw auger displacement piles.
- Bored piles
- Drilled and grouted minipiles – diameter less than 300mm.
- Screw piles – steel helix and shaft.
Factors including the nature of the near surface and deeper ground strata, loads to be carried, settlement tolerances, design life, noise, vibration, access constraints and equipment availability all combine to dictate the optimum pile type for any project.
The CMW design team has extensive experience in pile design and specification for deep foundations as well as pile retaining walls and piled rafts. Our experience, gained frequently through working on design and construct work with the major piling contractors, enables us help select the optimum pile type for problematical sites.