Pile foundations

A pile is a slender, deep foundation element that transfers loads from a structure through weak or compressible near-surface soils down to stiffer, more competent strata. Piles carry load both along their shaft (through skin friction) and at their base (through end bearing), and are used where shallow foundations cannot provide adequate bearing capacity or where settlement must be strictly limited.

Beyond vertical (axial) loads, piles are frequently subjected to significant horizontal (lateral) loads and moments — from wind, earth pressure, crane and machine forces, ship impact or seismic action. Under lateral load the pile behaves as a beam supported by the surrounding soil, and the soil resistance is strongly nonlinear: it depends on the deflection, the depth, and the type and strength of each soil layer.

Piles are commonly reinforced concrete, structural steel (tubular or H-sections) or a combination, and are installed by driving, boring, continuous flight auger (CFA) or as micropiles. The correct design must simultaneously satisfy the geotechnical bearing capacity of the ground and the structural capacity of the pile cross-section.

When making a design of a pile with greenPile, various considerations are analyzed:

Geometry
- Cross section (circular or rectangular)
- Diameter/width, length, free length and embedment depth
- Head fixity (free, fixed or pinned)
Geotechnical parameters
- Uniform or layered soil profiles with per-layer strength and stiffness
- p-y soil-reaction model per layer (API sand, Matlock soft clay, Reese, weak rock or user-defined)
- Water table depth
Loads:
- Horizontal loads
- Vertical (axial) loads
- Head moments and load eccentricity
- Multiple load combinations in both SLS and ULS
Concrete quality or steel grade
Type, placement, and amount of reinforcement (steel bars and/or fiber reinforcement)