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Feature of JST method
As for operation of JST method, the filling materials to be full with the
mixing head in order to agitate the material and the soil, the sandy soil,
the silt of course, with chemical grouting method improvement of the viscous
earth and the peat layer which are very difficult, is possible. Furthermore,
the making hole because it is auger system, improvement of gravel layer
is also possible. And the quantity of the filling materials is equal to
the void having the soil it is to be full and agitates and to mix by low
pressure generally, therefore can obtain the secure effect, The sinkage
with strange direction outflow it does not occur, but conventional chemical
grouting works it do complicated pressure management according to the design
is to be full at the quantity. In addition, due to the high pressure grouting,
bulging of the ground with being full may be occurred. Feature of JST method
is as follows.
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The ground where the flow of the underground water is fast |
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| In order with JST method to agitate the soil and the solidification material
mandatory making use of 2 types of solidification material and instantaneous
setting material, there are no times when the cement particle is let flow.
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| Two liquid instantaneous setting method |
Conventional method@ |
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Underflow conduitLiquid
ALiquid B |
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| Because with two liquid instantaneous setting method the gel, which is
formed, wraps the cement particle, outflow of the liquid by the underground
water is prevented. |
Because is time is required for hardening the cement, the outflow by the
underground water cannot ignore with conventional method. |
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 | Water bearing sand stratum |
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| Two liquid instantaneous setting methods |
Conventional method |
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| The gel, which is formed by the sodium silicate and the cement, prevents
the sedimentation of the cement particle, it is possible to make the uniform
revised body. Because of that, it can obtain high strength. |
The cement particle sediments. The result, the improving column becomes
uneven ones. |
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Acid soil |
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| The gel which is formed by the use of the instantaneous setting material
(sodium silicate) does not receive the attack by acid. In order to do the
role where this gel protects the cement particle, you can obtain satisfactory
revised strength even with the acid soil. |
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Cement Particle Acid |
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| Two liquid instantaneous setting method |
@Conventional method |
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Because gel tunic covers
the cement particle, acid is
not allowed to come near. |
Acid does not set due to react with the base in the cement Slurry. |
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| Principle of Installation |
| Like the rough sketch while providing two fluid channels inside the mixing
axis, the A liquid (the cement slurry), the B liquid (the instantaneous
setting material) supplying by low pressure respectively, with the individual
grouting pump, it mixes soil materials. |
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| When this part is clicked, the enlarged view is indicated. |
| Machine combination of JST excavator |
| Type |
Base
machine |
Mixing diameter |
Mixing
Depth
(Standard) |
Machine
weight |
| JST-30 |
20t class |
Ø 500 - 800 |
8.0m |
20t |
| JST-60 |
40t class |
Ø 500 - 800 |
12.5m |
40t |
| JST-80 |
80t class |
Ø 500 - 800 |
20.0m |
80t |
| JST-100 |
100t class |
Ø 600- 1,000 |
23.0m |
100t |
| JST-120 |
120t class |
Ø 600 - 1,000 |
26.0m |
120t |
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| Machine size |
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