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Author:
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2008-01-16 |
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I am working on a project constructing 110 km highway. We have an area of week soil which need to be improved. In Vietnam we normaly use "sand pile" to drain. I have heard that Korean have new technology of making this small "sand pile " with diameter of about 180 mm but with "fabric cover" which claimed to protect this "sand pile" from broken. Anyone knows about this please help.
MinhVN
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Author:
Huu Hung NGuyen
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2008-01-19 |
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It's very interesting. In Australia, we have stone column.
What project are you working on?
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Author:
MINH VO
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2008-01-21 |
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Hi Hung huu nguyen,
the treatment depth is pretty deep ( 30-40 m)and I have hearded that stone column is not applicable. Can you tell a bit more on your case, tks !
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Author:
Stephan Eberlein
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2008-01-29 |
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1)For a vertical drainage system it is possible to install geosynthetic vertical drains (to accellerate the consolidation). You can combine this drains with a load transfer platform using a geogrid reinforcement.
2) For a raft foundation of buildings and dams we are using soil stabilisation with vertical columns, too. The CSV-method (Combined Soil Stabilisation with Vertical Columns) was developed on the principles of ground improvement using lime columns. The method consists of driving a worm flight auger of about 10 cm diameter with a special drilling head into the ground to a maximum depth of about 12 to 20 m. The driving process leads to lateral displacement of the soil. At machine level, the worm flight auger passes through a funnel, where aggregate is added. On reaching final depth, the auger is withdrawn and aggregate is simultaneously pressed into the surrounding soil with a compacting effect. Thus, columns with a diameter of about 10 to 20 cm are produced. The resulting diameter depends on the strength characteristics of the surrounding soils and the production parameters. The CSV-method can be applied in soft cohesive soils and loose non-cohesive soils, which are statically displaceable. The method cannot be applied in soil strata including gravel and stone layers, as these cannot be displaced by the auger. The CSV-method can be applied where the ground water table lies near the ground surface. It has no vibration impacts on the surroundings.
The aggregate used usually consists of a dry mixture of sand (grain size 0/4) and cement. The compaction effect on the surrounding soil gives rise to pore water pressures, which upon dissipation, lead to drainage of the soil. pH-variations according to the type of aggregate used may also lead to dewatering of particular clay mineral structures. After seven days, the columns reach a compressive strength of about 5 to 10 N/mm².
With best regards from Germany
Stephan
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Author:
MINH VO
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2008-01-31 |
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Hi Stephan,
Thanks for yr info which your rapid pile CSV is interesting . It is correct that Bauer invented it ? Is there any further information I can get for this pile and its application.
For my highway project here, I think the Korean is talking about driving geosynthetic pipe with diameter of 180 mm and fill it with sand, is this correct and do u have and suggestion on it?
Regards from Vietnam
MinhVN
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to subject 'Geotechnical design and analysis'
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Follow-ups:
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Subject:
Korean ground improvement 