SP22.13330.2016

This solution is based on Russian standard SP22.13330.2016, which has two approaches for the calculation of soil bearing capacity:

1) Service resistance (R)

where:	γ_c1, γ_c2	-	coefficients of working conditions
	k	-	k = 1 if the strength characteristics are determined by the direct tests, or k = 1.1 (taken from the tables of Annex A)
	M_γ, M_q, M_c	-	bearing capacity factors
	k_z	-	k_z = 1 if b < 10 m, else k_z = 8/b+0.2 [m]
	b	-	width of foundation
	γ₁, γ₂	-	unit weight of soil above/below the footing bottom
	c	-	cohesion of soil
	d₁	-	depth of the footing bottom

Note: Parameters φ, c, γ₂ are taken as weighted average to the depth of z_SP, where z_SP = b/2 if b < 10 m, else z_SP = 4+0.1b [m]

2) Bearing capacity (N)

kde:	γ_c	-	coefficients of working conditions
	γ_n	-	coefficient of reliability (γ_n = 1.2; γ_n = 1.15; γ_n = 1.1 for structures with level of responsibility I, II, III)
	N_γ, N_q, N_c	-	bearing capacity factors
	s_γ, s_q, s_c	-	shape factors
	b_ef	-	effective width of foundation
	γ₁, γ₂	-	unit weight of soil above/below the footing bottom
	c	-	cohesion of soil
	d	-	depth of the footing bottom

Note: Parameters φ, c, γ₂ are taken along the Prandtl slip surface.

Literature:

SP22.13330.2016.

GEO5