| Symbol |
Meaning |
| (RF)ρ |
Settlement reduction factor for recessed piles |
| [K] |
Pile stiffness matrix |
| [S] |
Compliance matrix |
| A |
Skempton’s pore water coefficient |
| aE |
Factor to account for rate effects during cone penetration |
| AG |
Plan area of pile group |
| Ar |
Area ratio of pipe piles |
| Ar,eff |
Effective area ratio of pipe piles |
| au |
Adhesion factor |
| B′ |
Effective footing width |
Bq
|
Normalised pore pressure parameter from CPT tests |
| CC |
CPT correction factor for overburden stress |
Cc
|
Compression index |
| CN |
SPT blow count correction factor for overburden stress |
Cr
|
Recompression index |
cv
|
Coefficient of consolidation |
| Cα |
Creep coefficient |
D50
|
Median grain size |
De
|
Equivalent pier diameter |
| det |
Determinant of a matrix |
| Df |
Embedment depth of shallow footings |
Dr
|
Relative density of coarse-grained soils |
| e |
Void ratio |
eh
|
Elevation of lateral load resultant |
| E′ |
Drained Young’s modulus |
eb
|
Eccentricity along the footing width |
Eb
|
Young’s modulus of rockmass below the toe of socketed or end bearing piles |
el
|
Eccentricity along the footing length |
emax
|
Maximum void ratio |
| emin |
Minimum void ratio |
Ep
|
Young’s modulus of pile material |
| Er |
Young’s modulus of rockmass along the socket of socketed piles |
Es
|
Young’s modulus of soil |
| Et |
Young’s modulus of rockmass/soil along the recessed section of socketed piles |
Eu
|
Undrained Young’s modulus |
FR
|
Friction ratio from the interpretation of CPT tests |
Fr
|
Normalised sleeve friction resistance from CPT tests |
fs
|
Sleeve friction resistance measured during CPT tests |
fsf
|
Skin friction resistance of piles subjected to compressive loads, carrying units of stress |
| fsf,t |
Skin friction resistance of piles subjected to tensile loads, carrying units of stress |
g
|
Gravity coefficient |
G
|
Shear modulus |
G0
|
Small-strain shear modulus |
Gs
|
Specific gravity |
h
|
Hydraulic head |
Hf
|
Collapse load or ultimate geotechnical strength of a laterally loaded pile |
| Hw |
Serviceability lateral load acting on a pile |
| i |
Hydraulic gradient |
IB
|
Modified soil Behaviour Type index |
Ib
|
Pile head stiffness factor for end bearing single piles |
Ic
|
Soil Behaviour Type index |
Id
|
Design settlement influence factor for socketed piles |
Ir
|
Rigidity index |
Is
|
Settlement factor for single friction piles |
k
|
Soil permeability |
K
|
Bulk modulus |
K0
|
Earth pressure coefficient at-rest |
KA
|
Active earth pressure coefficient |
kc
|
Bearing capacity factor used in the LCPC method to estimate the end bearing resistance of piles from CPT data |
| KD |
Horizontal stress index from DMT tests |
Kf/Kc
|
Loading factor to account for the reduction in the normal stress acting at the soil-pile interface |
Kh
|
Coefficient of subgrade reaction of laterally loaded piles |
Khh
|
Swaying component of pile head stiffness |
Khr, Krh
|
Swaying-rocking component of pile head stiffness |
Kp
|
Relative pile material stiffness |
KP
|
Passive earth pressure coefficient |
| Krr |
Rocking component of pile head stiffness |
Ks
|
Punching shear resistance coefficient |
| Ksr |
Punching shear coefficient |
KSu
|
Conversion factor for estimating the bearing capacity of shallow foundations on fine-grained soils from CPT data |
| Kφ |
Conversion factor for estimating the bearing capacity of shallow foundations on coarse-grained soils from CPT data |
| L′ |
Effective footing length |
Le
|
Recess length of a socketed pile |
Lp
|
Length of soil plug |
M
|
Pile bending moment |
Mcs
|
Inclination of the critical state line in the p′–q space |
Mmax
|
Maximum bending moment along the length of a pile |
mv
|
Coefficient of volume compressibility |
Mw
|
Serviceability moment acting on pile head |
My
|
Yield bending moment of pile section |
n
|
Porosity |
N
|
SPT number of blow counts |
N*cp
|
Bearing capacity factor for drilled shafts in undrained soil (α-Method) |
N′ or Nl
|
Number of SPT blow counts corrected for overburden stress |
N′60
|
SPT number of blow counts for 60% hammer efficiency, corrected for overburden stress |
| N60 |
SPT number of blow counts for 60% hammer efficiency |
N70
|
SPT number of blow counts for standard 70% hammer efficiency |
| Nc |
Bearing capacity factor for footings on drained soil |
| Ncp |
Bearing capacity factor for driven piles in undrained soil (α-Method) |
| Ncu |
Bearing capacity factor for footings on undrained soil |
ng
|
Pile group efficiency |
| Nkt |
Cone factor |
| Nq |
Bearing capacity factor for footings on drained soil |
Nqp
|
Bearing capacity factor for piles in drained soil (β-Method) |
Nu
|
Alternative cone factor |
| Nγ |
Bearing capacity factor for footings on drained soil |
Nγ*
|
Modified bearing capacity factor for footings on layered sand |
Nφ
|
Bearing capacity factor for piles in rock |
| OCR |
Overconsolidation ratio |
| p |
Reaction from soil to lateral loading of a pile |
| p′ |
Mean effective stress |
| pa |
Atmospheric pressure |
| pf |
Ultimate soil reaction to lateral loading of pile |
| PI |
Plasticity Index |
q
|
Net bearing capacity, not accounting for the contribution of overburden soil, carrying units of stress |
Qb
|
End bearing resistance of piles, carrying units of force |
qb
|
End bearing stress at pile toe, at the ultimate limit state |
qbf
|
End-bearing resistance of piles, carrying units of stress |
Qbw
|
Serviceability load transferred to the pile toe |
qc
|
Cone resistance measured during CPT tests |
| Qext |
External force applied on soil surface, carrying units of force |
| qext |
External pressure applied on soil surface, carrying units of stress |
qf
|
Bearing capacity, or ultimate geotechnical strength in compression, carrying units of stress |
Qf
|
Collapse load, or ultimate geotechnical strength in compression, carrying units of force |
Qf,group
|
Collapse load or ultimate geotechnical strength of a group of piles subjected to axial compressive load, carrying units of force |
Qf,t
|
Collapse load, or ultimate geotechnical strength of piles in tension. carrying units of force |
| Qf,test |
Collapse load or ultimate geotechnical strength measured in situ |
| Qnf |
Negative skin friction resistance of piles, carrying units of force |
| qs |
Overburden pressure for shallow foundations, carrying units of stress |
| Qsf |
Skin friction resistance of piles subjected to compressive loads, carrying units of force |
Qsf,t
|
Skin friction resistance of piles subjected to tensile loads, carrying units of force |
| Qsfw |
Serviceability load transferred to the pile shaft, carrying units of force |
| qt |
Corrected cone resistance for pore pressure effects |
Qt
|
Dimensionless cone resistance |
Qtn
|
Normalised cone resistance |
| Qult |
Design axial compressive load for piles socketed in rock, carrying units of force |
Qw
|
Serviceability load, carrying units of force |
Qw,group
|
Axial compressive load acting on the cap of a group of piles under serviceability conditions, carrying units of force |
| Rs |
Factor for calculating settlement of a pile group connected with a rigid cap |
Rug
|
Ultimate geotechnical strength |
s
|
Pile spacing |
S*
|
Design (factored) action load at the Ultimate Limit State |
Sr
|
Degree of saturation |
St
|
Soil sensitivity |
| Su |
Undrained shear strength of fine-grained soils |
Tv
|
Time factor |
U
|
Average degree of consolidation |
u0
|
Hydrostatic pore pressure |
u2
|
Pore water pressure measured during CPT tests |
| uy,f |
Pile head displacement required to mobilise the end-bearing resistance of the pile |
V
|
Pile shear force |
| v′ |
Drained Poisson’s ratio |
vp
|
Poisson’s ratio of pile material |
| Vs |
Volume of solids |
VS
|
Shear wave velocity |
vs
|
Soil Poisson’s ratio |
| vu |
Undrained Poisson’s ratio |
| Vv |
Volume of voids |
| Vw |
Volume of water |
w
|
Water content or moisture content |
Wp
|
Weight of pile |
Ws
|
Weight of solids |
Ww
|
Weight of water |
y
|
Pile deflection |
y(0)
|
Pile head deflection |
α
|
Coefficient for calculating the skin friction resistance with LCPC CPT-based method |
α′
|
Correction factor for calculating the skin friction resistance with Schmertmann’s CPT-based method |
αi
|
Pile group interaction factor |
| β |
Factor for calculating the skin friction resistance of piles with the β-Method |
| βg,l |
Reduction factor to account for pile group effects under lateral loading – leading in line pile |
| βg,s |
Reduction factor to account for pile group effects under lateral loading – side-by-side pile |
| βg,sk |
Reduction factor to account for pile group effects under lateral loading – skewed pile |
| βg,t |
Reduction factor to account for pile group effects under lateral loading – trailing in line pile |
| γ |
Unit weight or bulk unit weight of soil |
γij
|
Shear strain |
γ′
|
Effective or submerged unit weight of soil |
γd
|
Dry unit weight of soil |
γsat
|
Saturated unit weight of soil |
γw
|
Unit weight of water |
| Δu |
Excess pore pressure |
ΔΙvy
|
Logarithm of clay sensitivity |
| Δσ |
Total normal stress increments in soil, due to the application of external loadings |
Δτ
|
Shear stress increments in soil, due to the application of external loadings |
ε
|
Normal strain |
ε50
|
Characteristic strain i.e., the strain corresponding to deviatoric stress equal to half the deviatoric stress at failure |
εvol
|
Volumetric strain |
κ
|
Alternative symbol for the recompression index (approximate) |
λ
|
Alternative symbol for the compression index |
λv
|
Correction factor for undrained shear strength measured from vane shear tests to account for rate effects |
| ν |
Specific volume |
ρ
|
Mass density or bulk mass density of soil |
ρd
|
Dry mass density of soil |
| ρe |
Immediate (elastic) settlement of shallow foundations and piles |
| ρpc |
Primary consolidation settlement of shallow foundations and earthworks |
ρs
|
Elastic pile shortening |
| ρsat |
Saturated mass density of soil |
ρsc
|
Secondary compression settlement or creep of shallow foundations and earthworks |
ρw
|
Mass density of water |
| σ |
Total normal stress |
σ′
|
Effective stress |
σ′0
|
Effective geostatic stress |
σ′c
|
Preconsolidation stress |
| σ′hf |
Normal effective stress acting at the soil-pile interface when the collapse load of the pile is reached |
| σ0 |
Total geostatic stress |
| σ1 |
Major principal stress |
| σ2 |
Intermediate principal stress |
| σ3 |
Minor principal stress |
σC
|
Confining stress |
| σc |
Unconfined compressive strength of rockmass |
σy
|
Design yield strength of pile material |
| τd |
Characteristic side shear resistance at shaft-rock interface of socketed piles |
φ′
|
Effective friction angle |
φcs
|
Critical state friction angle |
| φg |
Geotechnical strength reduction factor for shallow foundations, and for pile foundations when results of pile load tests are available |
φgb
|
Basic geotechnical strength reduction factor for pile foundations |
| φgbQf |
Design (factored) capacity of pile foundations |
φgQf
|
Design (factored) capacity of shallow foundations |
φi
|
Soil-pile interface friction angle |
| φi,cs |
Constant volume interface friction angle |
| φi,f |
Interface friction angle at failure |
| ψ |
Dilation angle |
ψt
|
Reduction factor for skin friction resistance due to Poisson effect |
| ω(0) |
Pile head rotation |
