Example 20: Influence of overburden pressure
Description of the problem
One of the advantages of
ELPLA
is that the bilinear relation of deformation for
the modulus of compressibility can be taken into consideration. Therefore,
an example was carried out by the Modulus of compressibility method (7) to show the influence
of overburden pressure on the settlements, contact pressures and moments.
A square raft has the dimension of 18*18 [m2]
under an elevated water tank was chosen as shown in the Figure.
For comparison,
ELPLA was used to study the influence
of overburden pressure (qv,
Wv)
on the values of settlements, contact pressures and moments for the
following three different assumptions:
a) Without taken into consideration the influence of
overburden pressure, where the modulus of compressibility for reloading
Ws
of the soil is taken to be equal to that of loading
Es.
b) The modulus of compressibility for reloading
Ws
of the soil is very great (Ws
= 9*108
[kN/m2]),
where the settlement due to the reloading of the soil is nearly zero.
c) The modulus of compressibility for reloading
Ws
= 12447 [kN/m ] is three times as the
modulus of compressibility for loading
Es
= 4149 [kN/m ], where the bilinear
relation of deformation for the modulus of compressibility is taken into
consideration.
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