Pile Shaft Resistance

Pile shaft resistance is given by:

where:	τ_s,i	-	unit pile shaft resistance in the i^th layer
	A_s,i	-	area of the pile shaft in the i^th layer

Unit pile shaft resistance for drained soils is given by:

where:	σ_ef	-	effective stress in the soil layer
	K_s	-	coefficient of lateral earth pressure
	f	-	technology coefficient
	φ	-	angle of internal friction
	τ_s,max	-	maximum limit for unit pile shaft resistance

According to CTE-DB SE-C the maximum limit for unit pile shaft resistance in drained soil is 120 kPa.

For undrained soils, the following expression holds:

where:	c_u	-	undrained shear strength of soil
	τ_s,max	-	maximum limit for unit pile shaft resistance

According to CTE-DB SE-C the maximum limit for unit pile shaft resistance in undrained soil is 100 kPa.

GEO5