Flat dilatometer test (DMT)
(1) This Annex gives an example of correlations between Eoed and DMT results. These correlations may be used to determine the value of the one-dimensional tangent modulus (Eoed = dσ/dε) from results of DMT tests, through:
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 lgKDMT
if 0,6 < IDMT < 3,0; then RM = RM0 + (2,5 – RM0)lg KDMT, in which
RM0 = 0,14 + 0,15(IDMT – 0,6);
if IDMT ≥ 3; then RM = 0,5 + 2lgKDMT
if KDMT > 10; then RM = 0,32 +2,18 lg KDMT
if values of RM < 0,85 are obtained in the above relationships, RM is taken to be equal to 0,85.
NOTE This example was published by Marchetti (2001), For additional information and design examples, see X.3.7.
Plate loading test (PLT)
K.1 Example of deriving the value of undrained shear strength
(1) This is an example of deriving the undrained shear strength (cu), which can be obtained using the following equation:
NOTE This example was published by Marsland (1972). For additional information and examples, see X.3.8.
K.2 Example of deriving the value of the plate settlement modulus
(1) This is an example of deriving the plate settlement modulus EPLT (secant modulus).
(2) For loading tests made at ground level or in an excavation where the bottom width/diameter is at least five times the plate diameter, the plate settlement modulus (EPLT) may be calculated from the general equation:
(3) If not determined in other ways, v is equal to 0,5 for undrained conditions in fine soil and 0,3 for coarse soil.
(4) If the test is made at the base of a borehole, the value of EPLT may be calculated from the equation:
NOTE This example was published by Burland (1969). For additional information and examples, sec X.3.8.
K.3 Example of deriving the value of coefficient of sub-grade reaction
(1) This is an example of deriving the coefficient of sub-grade reaction (ks) which may be calculated from the equation:
(2) The dimensions of the loading plate should be stated, when calculating values of ks.
NOTE This example was published by Bergdahl (1993). For additional information see X.3.8.
K.4 Example of a method to calculate the settlement of spread foundations in sand
(1) This is an example of deriving settlements directly. The settlements of a footing in sand may be derived empirically according to the relations given in Figure K.3, if the ground beneath the footing to a depth larger than two times the width is the same as the ground beneath the plate (see Figure K.2).
- 1 test plate
- 2 footing
- 3 influenced zones
- 1 loose
- 2 medium dense
- 3 dense
NOTE This example was published by Bergdahl el al (1993). For additional information and examples, see X.3.8.