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Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
5 REFERENCES (TNR 8)
Time (min)
0.01
0.1
1
10
100
1000 10000
Compression(mm)
0.0
0.5
1.0
1.5
2.0
R' s = 0 (Taipei Clay)
R' s = 0.23 (Taipei Clay)
R' s = 0.25 (Nantou Clay)
R' s = 0 (Nantou Clay)
Chang Y.C.E. 1981. Long term consolidation beneath the test fills at
Vasby, Sweden.
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Jamiolkowski M., Lancellotta R. and Wolski W. 1983. Precompression
and speeding up consolidation.
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, 1201-1206.
Johnson S.J. 1970. Precompression for improving foundation soils.
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111-114.
Mesri G., Ajlouni M.A., Feng T.W. and Lo, D.O.K. 2001. Surcharging
of soft ground to reduce secondary settlement.
Proc. of the 3rd
International Conference on Soft Soil Engineering
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Zeitlinger, Hong Kong, 55-65.
Mesri G. and Feng T.W. 1991. Surcharging to reduce secondary
Settlement.
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development –Theory to Practice
, 1, Yokohama, Japan, 359-363.
Mesri G., Stark T.D., Ajlouni, M.A. and Chen C.S. 1997. Secondary
compression of peats with or without surcharging.
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, ASCE, 123 (5),
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Figure 5. Consolidation curves of different soils with or without
surcharging
3 CONCLUSIONS
The following conclusions are based on data and discussions
presented in previous paragraphs. Surcharging with higher
effective surcharge ratio reduces secondary compression to a
lower magnitude. For the same effective surcharge ratio,
surcharging without reloading reduces more secondary
compression than surcharging with reloading. The post-
surcharge secondary compression is also a function of the
surcharging stress history achieved in the consolidating soil.
For small effective surcharge ratios realized in practice, the
secondary compression of soil may not be reduced sufficiently
and excessive long term settlement resulting from secondary
compression may still be expected. Structures on natural thick
soil deposit with high compressibility ratio, e.g. greater than
0.04, and improved by prefabricated vertical drains are highly
susceptible to excessive long term secondary settlement. In this
case, surcharging technique is capable of reducing the
secondary settlement, as long as a proper value of effective
surcharge ratio is used in design and achieved in soil.
Sowers G.F. 1964. Fill settlement despite vertical sand drains.
Journal
of the Soil Mechanics and Foundation Division
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Terzaghi K., Peck R.B. and Mesri G. 1996.
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Engineering Practice
, 3
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4 ACKNOWLEDGEMENTS
This study is partly supported by the National Science Council
of Taiwan, under Grant No. NSC 98-2221-E-033-052-MY2,
and by Chung Yuan Christian University. Great thanks are
given to these organizations for their continuous support.
