Annex E.1
(informative)
Dynamic Probing (DP)
(1) This is an example of derived values for the density index ID from the dynamic probing DP test, for different values of the uniformity coefficient Cu (range of validity 3 ≤ N10 ≤ 50):
a) poorly graded sand (Cu < 3) above groundwater
ID = 0,15 + 0,260 log N10 (DPL)
ID = 0,10 + 0,435 log N10 (DPH)
b) poorly graded sand (Cu ≤ 3) below groundwater
ID = 0,21 + 0,230 log N10 (DPL)
ID = 0,23 + 0,380 log N10 (DPH)
c) well graded sand-gravel (Cu ≥ 6) above groundwater
ID = − 0,14 + 0,550 log N10 (DPH).
For additional information and examples see, Annex M.
ANNEX E.2
(informative)
Dynamic Probing
(1) This is an example of deriving the effective angle of shearing resistance ϕ' from the density index ID, for bearing capacity calculations of cohesionless soils.
| Soil type | Grading | Range of ID, [%] | Angle of shearing resistance ϕ' |
| slightly fine-grained sand, sand, sand-gravel |
poorly graded, (U < 6) |
15—35 (loose) 35—65 (medium dense) >65 (dense) |
30 32,5 35 |
| sand, sand-gravel, gravel | well graded, (6 ≤ U ≤ 15) |
15—35 (loose) 35—65 (medium dense) > 65 (dense) |
30 34 38 |
For additional information and examples, see Annex M.
ANNEX E.3
(informative)
Dynamic Probing (DP)
(1) This is an example of the derivation of the vertical stress dependent oedometer settlement modulus Eoed, frequently recommended for settlement calculation of spread foundations, defined as follows:
where:
v is the stiffness coefficient;
w is the stiffness exponent; for sands with a uniformity coefficient U ≤ 3:
w = 0,5; for clays of low plasticity (Ip ≤ 10; wL ≤ 35): w = 0,6;
σ'v is the effective vertical stress at the base of the foundation or at any depth below it due to overburden of the soil;
σ'p is the effective vertical stress caused by the structure at the base of the foundation or at any depth below it;
pa is the atmospheric pressure
Ip is the plasticity index
wL is the liquid limit.
(2) Values for the stiffness coefficient v can be derived from DP tests using for example the following equations, depending on the soil type:
a) closely graded sands (U ≤ 3) above groundwater
v = 214 log N10 + 71 (DPL; range of validity: 4 ≤ N10 ≤ 50)
v = 249 log N10 + 161 (DPH; range of validity: 3 ≤ N10 ≤ 10)
b) low plasticity clays of at least stiff consistency (0,75 ≤ Ic ≤ 1,30) and above groundwater (Ic is the consistency index)
v = 4 N10 + 30 (DPL; range of validity: 6 ≤ N10 ≤ 19)
v = 6 N10 + 50 (DPH; range of validity: 3 ≤ N10 ≤ 13).
For additional information and examples see, Annex M.
ANNEX F
(informative)
Weight Sounding Test (WST)
| Relative density | Weight sounding resistance1), halfturns / 0,2 m | Angle of shearing resistance2) [N'] | Drained Young's modulus3), Em [MPa] |
| very low low medium high very high |
0—10 10—30 20—50 40—90 > 80 |
29—32 32—35 35—37 37—40 40—42 |
<10 10—20 20—30 30—60 60—90 |
| 1) Before determination of the relative density the weight sounding resistance in silty soils should be divided by a factor of 1,3. 2) Values given are valid for sands. For silty soils a reduction of 3° should be made. For gravels 2° may be added. 3) Values given for the drained modulus correspond to settlements after 10 years. They are obtained assuming that the vertical stress distribution follows the 2:1 approximation. Furthermore some investigations indicate that these values can be 50 % lower in silty soils and 50 % higher in gravelly soils. In overconsolidated cohesionless soils the modulus can be considerably higher. When calculating settlements for ground pressure greater than 2/3 of the design pressure in ultimate limit state the modulus should be set to half the values given in this table. |
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(1) Table F.1 gives an example of the derived values of the angle of shearing resistance ϕ' and drained Young's modulus of elasticity Em, estimated from weight sounding resistance. This example correlates the mean value of weight sounding resistance in a layer to the mean values of N' and Em.
(2) If results of weight sounding tests only are available the lower value in each interval for the angle of shearing resistance and Young's modulus in table F.1 should be selected.
(3) When evaluating weight sounding resistance diagrams for application in table F.1, peak values caused e.g. by stones or pebbles should not be accounted for. Such peak values are common in weight sounding tests in gravel.
For additional information and examples, see Annex M.
ANNEX G
(informative)
Field Vane Test (FVT)
(1) Examples of correction factors to obtain the undrained shear strength from the measured value are shown in figures G.1 and G.2, based on local experience and back calculations of slope failures.
(2) Correction factors based on figure G.1 may be used in soft normally consolidated clays.
(3) Correction factors based on figure G.2 may be used in overconsolidated clays.
(4) If more than one method correcting the measured value is used, the value of the correction factor which will give the lowest value of the undrained shear strength should be applied.
(5) A greater correction factor than 1,2 should not be used without support from supplementary investigations.
(6) In fissured clays a correction factor as low as 0,3 can be necessary.
For additional information and examples, see Annex M.
ANNEX H
(informative)
Fiat Dilatometer Test (DMT)
(1) The following is an example of correlations that may be used to determine the value of the one-dimensional tangent modulus Eoed= dσ'/dε from results of DMT tests:
Eoed = RM × Edmt
in which Rm is estimated either on the basis of local experience or using the following relationships:
— if IDMT ≤ 0,6; then RM = 0,14 + 2,36 log KDMt
— if IDMT ≥ 3,0; then RM = 0,5 + 2 log KDMT
— if 0,6 < IDMT < 3,0; then RM = RM0 + (2,5 − RM0) log KDMT,
in which RM0 = 0,14 + 0,15 (IDMT − 0,6)
— if Kdmt > 10; then RM= 0,32 + 2,18 log KDMT
if values of RM < 0,85 are obtained in the above relationships, RM is taken equal to 0,85. For additional information and examples, see Annex M.
