Annex G
(Informative)
Dynamic probing test (DP)
G.1 Examples for correlations between number of blows and density index
(1) These are examples of the density index (ID) from the dynamic probing DP test, for different values of the uniformity coefficient (CU) (range of validity 3 ≤ N10 ≤ 50):
poorly-graded sand (CU ≤ 3) above groundwater
ID = 0,15 + 0,260 lgN10L (DPL)
ID = 0,10 + 0,435 lgN10H (DPH)
poorly-graded sand (CU ≤ 3) below groundwater
ID = 0,21 + 0,230 lgN10L (DPL)
ID = 0,23 + 0,380 lgN10H (DPH)
well-graded sand-gravel (CU ≥ 6) above groundwater
ID = –0,14 + 0,550 lgN10H (DPH).
NOTE These examples were published by Stenzel et al. (1978) and in DIN 4094-3. For additional information and examples, see X.3.4.
G.2 Example of a correlation between the effective angle of shearing resistance and the density index
(1) This is an example of deriving the effective angle of shearing resistance (φ') from the density index (ID), for bearing capacity calculations of coarse soil (see Table G.1).
| Soil type | Grading | Range of ID % |
Effective angle of shearing resistance (φ') º |
|
| Slightly fine-grained sand. Sand, sand-gravel | Poorly graded, (CU < 6) |
15–35 | (loose) | 30 |
| 35–65 | (medium dense) | 32,5 | ||
| > 65 | (dense) | 35 | ||
| Sand, sand-gravel, gravel | Well-graded, (6 ≤ CU ≤ 15) | 15–35 | (loose) | 30 |
| 35–65 | (medium dense) | 34 | ||
| > 65 | (dense) | 38 | ||
NOTE This example was published in DIN 1054-100. For additional information and examples, see X.3.4.
G.3 Example of establishing the stress-dependent oedometer modulus from DP results
(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
for sands with a uniformity coefficient CU ≤ 3: w2 = 0,5;
for days of low plasticity (Ip ≤ 10; wL ≤ 35); w2 = 0,6;
(2) Values for the stiffness coefficient (w1)can be derived from DP tests using for example the following equations, depending on the soil type:
poorly-graded sands (CU ≤ 3) above groundwater
w1 = 214 lgN10L + 71 (DPL; range of validity: 4 ≤ N10L ≤ 50)
w1 = 249lgN10H + 161 (DPH; range of validity: 3 ≤ N10H ≤ 10)
low-plasticity clays of at least stiff consistency (0,75 ≤ Ic ≤ 1,30) and above groundwater (Ic is the consistency index)
w1 = 4N10L + 30 (DPL; range of validity: 6 ≤ N10L ≤ 19)
w1 = 6N10H + 50 (DPH; range of validity: 3 ≤ N10H ≤ 13).
NOTE These examples were published by Stenzel et al. (1978) and Biedermann (1984) and in DIN 4094-3:2002. For additional information and examples, see X.3.4.
G.4 Example of correlations between the cone penetration resistance and the number of blows
(1) This is an example of estimating the cone penetration resistance (qc) in sands and sand-gravel mixtures from results with the dynamic probing test DPH to derive ultimate bearing capacities of piles from corresponding correlations established from static pile load rests (see Figure G.1, 4.3.4.2 (1)P and D.6).
Key
- (x) Number of blows, (y) Cone penetration resistance (qc),
- 1 Poorly-graded sand above groundwater,
- 2 Poorly-graded sand below groundwater,
- 3 Well-graded sand and gravel above groundwater,
- 4 Well-graded sand and gravel below groundwater.
NOTE This example was published by Stenzel et al. (1978) and in DIN 4094-3. For additional information and examples, see X.3.4.
G.5 Example of a correlation between number of blows of different dynamic penetrometers
(1) This is an example for correlations between the number of blows N10L of the dynamic probing test DPL and the number of blows N10H of the dynamic probing test DPH for poorly-graded sands (CU < 3) above the groundwater level:
a) Input: DPH results;
N10L = 3N10H;
Range of validity: 3 ≤ N10H ≤ 20.
b) Input: DPL results;
N10H = 0,34N10L;
Range of validity: 3 ≤ N10L ≤ 50.
NOTE These examples were published by Stenzel (1978) and Biedermann (1984) and in DIN 4094-3:2002. For clays, see Butcher, A.P. McElmeel, K., Powell, J.J.M. (1995). For additional information and examples, see X.3.4.
