Abstract
This study aims to clarify mechanical property of volcanic soils with particle crushing. Site investigations using SPT, CPT and SCP tests were conducted at the volcanic ach grounds in Hokkaido. In addition, laboratory tests on disturbed and undisturbed samples taken from the in-situ volcanic ach grounds were also carried out to reveal their static shear strength and cyclic undrained strength. From the results of triaxial compression tests, it was found that there is a remarkable dependency of stress-strain-strength properties of undisturbed and reconstituted volcanic soils on crushing of constituent particles, when the test is performed under the stress system with the increase in effective mean principal stress. Therefore, the effects of cementation and fabric anisotropy on the angle of internal friction are insignificant for undisturbed crushable volcanic soils. On the other hand, the liquefaction strength under low confining pressure is greatly influenced by cementation, grain size and fines content. Furthermore, the correlation between the in-situ sounding data and strength parameters obtained from laboratory test is also discussed in this paper.
