Geoscience Reference
In-Depth Information
Figure 7.45
Schematic diagram of the new DMM technique (
after
Kazemian, 2011).
2. After arriving at a stable vacuum condition, the injection auger is operated to make
injection wells at predefined location and depths (between vacuum slots).
3.
The selected new binder is injected in the injection wells by using the injection
pump simultaneously with the vacuum.
4.
To achieve homogeneity in the migration of chemical binders, and at the same time
speedy dispersion from the injection nozzle, a high-quality vacuum pump which
is capable of delivering a satisfactory level of stable flow is used (Figure 7.45).
Advantages of the new DMM technique
1. The function of the vacuum technology is mainly to distribute the injected binder
in soft and organic soils and also to achieve a lower magnitude of consolidation
in the soil. In this method, the vacuum forms a homogenized mixture of soil and
binder.
2. To get much higher strength by using a new binder in comparison with conven-
tional ones.
3. No need to lower the water table. (The ground water level rather helps as a
distribution tool after achieving a stable vacuum within the soil.)
4.
The horizontal permeability of soils is higher than the vertical permeability and
this method helps to speed up stabilization and leads to homogenization.
5.
Because of the very low strength and loose matrix of soft clays and organic soils,
using a high-pressure injection pump for stabilization is impractical. In this method
we can use low-pressure injection pumps with high efficiency.
6.
By applying this method, higher efficiency is achieved in a short time and the ratio
of affected area method is much higher than with ordinary injection. There is no
need to use a super jet pump for the soil.
A newDMMapparatus based on the above idea was developed at UPM (Universiti
Putra Malaysia) in 2010 by Kazemian (2011). The vacuum part of this method is the
same as the cap-drain (CPVD) method (Fujii
et al
., 2002) and hence there is no need
