Pile (Geometry)

Pile	Description
Icon
Modules where available
Geometry	Straight, placed in any arbitrary angle but 90° to vertical
Cross-section	Arbitrary concrete, steel, timber, and certain types of composite profiles
Material	Concrete, steel, timber, composite
End condition	Rigid and hinged, or custom defined by Point-point connection
Soil springs	Support springs, Negative shaft friction
Load direction	Arbitrary in
Load type	Point/line load (force and moment), Line support motion
Available analysis results	Displacement, stresses, stability and vibration shape in
Available design	-
Default Short Command	PILE

Table: Pile properties

Definition steps

1. You need to define the soil first.
2. Start  Pile command from   / Foundation tabmenu and choose  Define.
3. Set the properties of the new Pile in  Default settings:
   

• Identifier (General)
  The program automatically generates it, but you can define custom value. Identifier (ID) number can be displayed in model view (Display settings).
• Rotation (General)
  You can set the direction of the local y axis.
• Cross-section (Section)
  The section of the pile can be selected from the Section library or you can set a Composite one for it. (Cross-sections)
  
  
  The available composite sections for simple pile are the followings:
  
  

• Material
  Concrete, steel, timber or composites can be set as material for pile Analysis.
• End conditions
  On the End conditions tab User can set the top release of the pile, which can be useful in case piles are connected to a foundation slab. The connection can be either fixed or hinged.
  
• Support springs (Soil springs)
  In the Soil springs tab you can overwrite the automatically calculated values of any support, such as Lateral/ Vertical line motion springs, Vertical pile tip springs or Vertical plastic limit forces.

References:

• Bogumił Wrana (2015) Pile load capacity – calculation methods. Studia Geotechnica et Mechanica, Vol. 37, No. 4, pp. 83-93

• NAVFAC DM 7.2 (1984): Foundation and Earth Structures, U.S. Department of the Navy
• Skempton A.W. (1959), Cast-in-situ bored piles in London clay, Geotechnique, Vol. 9, No. 4, pp. 153–173
• Qian-qing Zhang, Shu-cai Li, Fa-yun Liang, Min Yang, Qian Zhang (2014) Simplified method for settlement prediction of single pile and pile group using a hyperbolic model. International Journal of Civil Engineering Vol. 12, No. 2, Transaction B: Geotechnical Engineering, pp. 146-159
• Vesic, A.B. (1963) Beams on Elastic Subgrade and the Winkler’s Hypothesis. Proceedings of the 5th International Conference of Soil Mechanics, pp. 845-850
  
  
   
• Negative shaft friction (Soil springs)
  β_neg is the factor for negative shaft friction for drained soils (default value is also assumed to 1.0). This load is applied as a linearly variable line load along the pile, and its value can be changed by the modification of the α_neg and β_neg values (each stratum has one value) together with neutral level:
  

• Click Option to open Pile option dialog. Here you can declare the Type of pile or the Surface surcharge (affecting the vertical stresses in case of drained soils), the division length of line supports and can decide the method of the Section perimeter’s calculation.
  

The feature has some important limitations! Pile model is used only for analysis purpose (displacements, internal forces), geotechnical design calculations are not implemented yet. During the calculations soil must not be modelled as soil element. Negative shaft friction is considered in a load combination only if it includes “Neg. shaft friction” load case, which is generated automatically when a pile is created in the model with non-zero neutral level.