The INSITU
program interprets statical and dynamical geotechnical in situ tests.
In order to interpret the SPT tests, the program utilises the main
correlations that are normally used to determine the geotechnical
parameters of a soil.
One
should enter the geometrical and geotechnical parameters pertaining
to the stratigraphy surveyed trough drilling and the number of blows
relative to each test; some corrective parameters can be entered
that enable one to limit the perturbations in the interpretation
of the data caused by the way the test is performed and the type
of instrument that is used.
Based
on this simple information, the program determines the relative density,
the friction angle, the effective vertical and total stress, the confined
modulus, Young's modulus, the upper limits of the settlement/admissible
load ratio, the point resistance, the dynamic shear modulus and the
cyclical stress of the terrain traversed, when possible using different
calculation methods to permit comparison of the results.
When
interpreting the CPT test results, the program divides, as normal
practise, granular terrains with a prevalence of sand from cohesive
terrains made up mostly of clay.
For
granular terrains, it is able to determine (from the data that has
been entered) the friction angle, the drained compressibility and
the relative density, while for cohesive terrains it evaluates the
shear resistance in undrained conditions, compressibility, sensitivity
and the degree of overconsolidation.
For
the interpretation of this test the data required are, yet again,
extremely simple: the classification of the terrain that has to
be used, the measured test values and any correction factors that
prove necessary to limit perturbations in the interpretation of
the data.
With
the DP test interpretation, which is mainly used in granular terrains
and to localise resistant strata, the program supplies all the information
previously mentioned for the SPT test.
The
INSITU program can be adapted to any measurement instrument.
