Civil Engineering Reference
In-Depth Information
Figure 16.2
Variations of water content in the ground in normally consolidated and overconsol-
idated soils.
the difference between the water contents at C and D is much smaller and the water
contents themselves are smaller. For the heavily eroded soil the smaller variation of
water content with depth is a result of the very large maximum past stress.
16.3 Changes of state and yield stress ratio in
natural soils
The effects of structure can be regarded as changes of state and changes of the state
boundary surface and both give rise to changes in the yield stress ratio
Y
0
. Yield stress
ratio is essentially the distance of the current state from the state boundary surface and
it was defined in Sec. 8.3. In the simple theories of soil mechanics the state can only
change by loading on the state boundary surface and unloading to a new state inside
the surface. Figure 16.3 shows the state of a soil at A inside the state boundary surface
