Annex J

(Informative)

# Flat dilatometer test (DMT)

(1) This Annex gives an example of correlations between *E*_{oed} and DMT results. These correlations may be used to determine the value of the one-dimensional tangent modulus (*E*_{oed} = dσ/dε) from results of DMT tests, through:

*E*_{oed} = *R*_{M}×*E*_{DMT}

in which *R*_{M} is estimated either on the basis of local experience or using the following relationships:

if *I*_{DMT} ≤ 0,6; then *R*_{M} = 0,14 + 2,36 lg*K*_{DMT}

if 0,6 < *I*_{DMT} < 3,0; then *R*_{M} = *R*_{M0} + (2,5 – *R*_{M0})lg *K*_{DMT}, in which

*R*_{M0} = 0,14 + 0,15(*I*_{DMT} – 0,6);

if *I*_{DMT} ≥ 3; then *R*_{M} = 0,5 + 2lg*K*_{DMT}

if *K*_{DMT} > 10; then *R*_{M} = 0,32 +2,18 lg *K*_{DMT}

if values of *R*_{M} < 0,85 are obtained in the above relationships, *R*_{M} is taken to be equal to 0,85.

where

*I*

_{DMT}

*K*

_{DMT}

NOTE This example was published by Marchetti (2001), For additional information and design examples, see X.3.7.

Annex K

(informative)

## 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 (*c*_{u}), which can be obtained using the following equation:

where

*p*

_{u}

*z*

*N*

_{c}

*N*

_{c}= 6

*N*

_{c}= 9

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 *E*_{PLT} (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 (*E*_{PLT}) may be calculated from the general equation:

where

*p*

*s*

*p*including creep settlements;

*b*

*v*

(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 *E*_{PLT} may be calculated from the equation:

where

*C*

_{z}

*C*as a function of plate diameter

_{z}*b*and depth

*z*for PLT results obtained with a uniform circular load at the base of an unlined shaft

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 (*k*_{s}) which may be calculated from the equation:

where

*p*

*s*

*p*including creep settlements.

(2) The dimensions of the loading plate should be stated, when calculating values of *k*_{s}.

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).

Key

*b*

_{1}

*b*

*p*

*s*

_{1}

*s*

- 1 test plate
- 2 footing
- 3 influenced zones

Key

*b*/

*b*

_{1}

*s*/

*s*

_{1}

- 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.