Symbols and units

Every symbol Rischio writes, in the editor and in the calculation report: what it stands for, its unit and its JSON key.

Units are SI throughout: kN, m, kPa, kN/m³ and degrees. A wall and a strip footing are worked per metre of length, so their forces are in kN/m and their moments in kN·m/m.

Inputs

Symbol	Name	Unit	JSON
$x$	Position from the toe	m	x
$B$	Width	m	width
$L$	Length	m	length
$H$	Height	m	height
$b_1$	Bottom width	m	bottom_width
$b_2$	Top width	m	top_width
$\omega$	Back face batter	°	back_batter
$D$	Embedment depth	m	embedment_depth
$t$	Thickness	m	thickness
$d$	Diameter or side	m	diameter
$s$	Spacing	m	spacing
$n_x$	Piles along x		count_x
$n_y$	Piles along y		count_y
$\beta$	Backfill slope	°	surface_slope
$z_\mathrm{w}$	Depth	m	depth
$\gamma$	Unit weight	kN/m³	unit_weight
$\gamma_\mathrm{sat}$	Saturated unit weight	kN/m³	saturated_unit_weight
$c'$	Cohesion	kPa	cohesion
$\varphi'$	Friction angle	°	friction_angle
$c_\mathrm{u}$	Undrained shear strength	kPa	undrained_shear_strength
$\delta$	Interface friction angle	°	base_friction_angle
$E$	Elastic modulus	kPa	elastic_modulus
$\nu$	Poisson's ratio		poisson_ratio
$q$	Surcharge	kPa	q
$V$	Vertical load	kN	vertical
$H$	Horizontal load	kN	horizontal
$M_B$	Moment along the width	kN·m	moment_width
$M_L$	Moment along the length	kN·m	moment_length
$S$	Longitudinal slope	m/m	slope
$Q$	Discharge	m³/s	discharge

Results

Symbol	Name
$B$	Width
$V$	Vertical load
$H$	Horizontal load
$e_B$	Eccentricity along the width
$B'$	Effective width
$\beta$	Load inclination
$q$	Overburden at the base
$\gamma'$	Effective unit weight under the base
$q_u$	Ultimate bearing capacity
$q_{max}$	Maximum contact pressure
$q_{min}$	Minimum contact pressure
$H$	Depth of influence
$E_s$	Average elastic modulus
$\mu_s$	Average Poisson's ratio
$I_s$	Shape factor
$I_f$	Depth factor
$S_e$	Elastic settlement
$B$	Base width
$W_s$	Weight of the soil over the heel
$H'$	Height of the virtual back
$q$	Surcharge
$\Delta P_{a,h}$	Thrust of the surcharge
$P_{a,h}$	Active thrust, horizontal
$P_{a,v}$	Active thrust, vertical
$P_w$	Water thrust
$z_c$	Depth of the tension crack
$P_{wc}$	Thrust of the water in the crack
$P_{a,h}^{\text{no crack}}$	Active thrust before the crack (textbook)
$P_p$	Passive resistance
$u_{heel}$	Uplift pressure at the heel
$u_{toe}$	Uplift pressure at the toe
$U$	Uplift
$x_U$	Lever arm of the uplift
$\Sigma M_R$	Resisting moment
$\Sigma M_O$	Overturning moment
$\Sigma V$	Total vertical force
$\Sigma H$	Total horizontal force
$\delta$	Friction angle at the base
$c_a$	Adhesion at the base
$R$	Resistance to sliding
$e$	Eccentricity of the resultant
$Q$	Load
$p$	Perimeter of the pile
$z_c$	Critical depth
$Q_s$	Shaft resistance
$A_p$	Area of the toe
$q_p$	Unit toe resistance
$Q_p$	Toe resistance
$Q_u$	Ultimate capacity of a pile
$Q_{pile}$	Load per pile
$n \, Q_u$	Sum of the single piles
$Q_{block}$	Capacity of the group as a block
$\eta$	Group efficiency
$Q_g$	Capacity of the group