PARAMETRIC STUDIES FOR OBTAINING THE DIMENSION OF SOIL IMPROVED AREA
ABSTRACT: In many
cases, to improve
weak soil (e.g.
grouting method or
other method), it must
have the obvious understanding about the design of
appropriate size of soil improved area, for example, road projects or deep
excavation projects. The essential input
parameters are a certain width, a depth, and also the improved area stiffness.
The important question is why
it is
generally recommended to
make deeper area
than performing wider
area. This question
can beanswered with parametric
studies by using the Beam on Elastic Foundation Method which is proposed by
Hetenyi (1946). Soil in this method is modeled as Winkler's spring. And also,
the relevant information of the soil settlement related to the soil stiffness
and that spring
could be analyzed
with this approach.
In this paper,
the design chart
is developed with considering several of simple
combinations among the contact load pressures, the appropriate sizes, and the
stiffness of improved area (e.g.
improved soil modulus).
So, the deeper
improved soil is
simulated and shown that
if the improved soil thickness is increased, the
settlement will be reduced. But, for another case with particular loading
condition and soil stiffness, there is no effect if the area of improved soil
is wider and the behavior is similar and goes through the same one pattern only. In
this paper, it
is developed the
design curve considering
the load acting
on the improved
soil area, modulus of improved
area parameters and soil modulus of subgrade reaction, the normalized curve for
getting improved area thickness and width is generated. It is shown if the load
is increased then the width of improved soil area has to be increased for
a certain thickness. Because of
linear elastic approach,
it is shown
that the variation
of five parameters (soil modulus, of improved area,
load, thickness and length of improved area, and modulus of subgrade reaction)
gives the same curves
for each combinations
of certain value
of k/su. Using this
normalized design chart
as a function
of pressures, width of loading, a
soil width and thickness, and soil stiffness, it can be used as the appropriate
preliminary dimension of improved soil area.
Author: Budijanto Widjaja
Journal Code: jptsipilgg080004
