Anti-slide piles are vertical structural elements, which increase the slope stability. If the anti-slide pile intersects into assessed slip surface, then for the calculation of the factor of safety is introducing passive (resisting) force P which corresponds to bearing capacity of pile Vu. This step is accomplished by the higher value of safety factor SF.
It is assumed that the pile is always vertical. Passive (resisting) force P at the intersection point with the slip surface is considered either in the horizontal direction or in a direction which corresponds to the inclination of the slip surface at that location.
Presentation of the direction of passive (resisting) force
The value of passive (resisting) force P is always determined at 1 rm width of the slope with respect to spacing between piles. Bearing capacity of pile Vu can be specified as either with a constant value along the length of pile, or increasing linearly away from the pile base upwards.
Constant and linear distribution of bearing capacity Vu along the pile length
Linear increase of bearing capacity of pile is described by gradient K, which is the ratio of the pile length, on which the ultimate bearing capacity Vu is achieved due to the length of pile below the ground surface. If the value of gradient K approaches zero, the linear distribution of bearing capacity Vu is close to constant distribution.