** Determination of Compression Index for Toyoura Sand and ......Determination of Compression Index...

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Determination of Compression Index for Toyoura Sand and Shirasu by Triaxial Compression Test

Koji MISUMI* and Syohei NOMURA**

The determination procedure of sandy soil’s compression index is proposed in this paper. At first, a series of triaxial compression test datum are obtained under constant mean normal stress condition. Secondly, this method is carried out by fitting some equations to sandy soil’s shearing behaviors (i.e., dilatancy behaviors). Finally, sandy soil’s compression index is obtained by relationship between maximum positive volumetric strains and initial specific volumes. The validity of this method is confirmed by applying to Toyoura sand and local soil Shirasu. And the differences of these soils’ compression index are made clear by comparison with their values.

Keywords : compression index, triaxial compression test, dilatancy, Toyoura sand, Shirasu

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1) A. Schofield and P. Wroth, Critical State Soil

Mechanics, McGRAW-Hill Publishing Company

Limited, pp.124-127 (1968).

J. H. Atkinson and P. L. Bransby, The Mechanics

of Soils, An Introduction to Critical State Soil

Mechanics, McGRAW-Hill Book Company

Limited, pp.235-262 (1978).