SG (Slot)

From fig. 7 it can also be derived that apart from the fact
that the values for the angle of internal friction for single
aggregates are always the highest compared to those of the
bulk soil and homogenized material, the undisturbed soils
have higher values for the angle of internal friction at
smaller loads (< 50 KPa) than at higher ones. These
differences are more pronounced the wetter the soil has been
(Baumgartl and Horn, 1990).
Conclusions
The soil strength of structured soils differs to a
great
extent from that of homogenized material whereby the soil
moisture suction further alters soil strength. Furthermore
simple aggregates in structured soils are also stronger (i.e.
they have a higher value of the angle of internal friction
and cohesion compared with the bulk soil or the homogenized
material.
Thus, stress. distribution (intensity and spatial direction)
varies in dependence of soil and machinery parameters. Thus,
the determination of compressibility requires multifunctional
methods in order to deal adequately with the complex
connection between the soil requirements of growing plants
and the soil's physical characteristics as affected by the
loads which it has to support.
References
Baumgartl, Th. and R. Horn 1990: The effect of aggregate
stability on soil compaction. Soil Tillage Res. in
press
Burger, N., M. Lebert and R. Horn 1988:
Prediction of the compressibility of arable land. In:
Interaction of Structured soils with Water and
External Forces. Eds: J. Drescher, R. Horn Catena
Supplement 11, 141-152
Ehlers, w. 1975: EinfluB vom wassergehalt, Struktur und
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