Base Resistance of Bored Pile

Pile base resistance is calculated as follows:

where:	k₁	-	factor of increasing base resistance due to pile length L
	A_s	-	pile base area
	q_dp	-	bearing capacity at the pile base

Note: The determination of coefficient of increasing base resistance due to pile length k₁ is explained in chapter 6.4.1.3

Bearing capacity at the pile base in drained soils is given by:

where:	N_c, N_q, N_γ	-	bearing capacity factors
			for
			for


	c_d	-	soil cohesion at the pile base
	φ_d	-	angle of internal friction
	γ₁	-	average soil weight along the pile
	L	-	pile length
	γ₂	-	soil weight below the pile base
	d	-	pile diameter

For undrained soils, the following expression holds:

where:	c_u	-	undrained cohesion at the pile base
	q	-	total vertical stress at the pile base

Literature:

CSN 73 1004 (July 2020)

GEO5