Mechanical properties of undisturbed and reconstituted serpentinite originated from the Kamuikotan belt in Hokkaido

Abstract

Various laboratory tests such as triaxial test, reversal direct box shear test, swelling pressure test, slaking test were carried out to investigate the mechanical properties of serpentinite using the undisturbed and reconstituted samples originated from the Kamuikotan belt in Hokkaido. From the test results, it was concluded as follows.
The residual angle of shearing resistanceφ'_r as well as the peak angle of shearing resistanceφ'_p were unexpectedly large by showingφ'_r=27-28° and φ'_p=31 ± 2° irrespective of the state of undisturbed or reconstituted. But the undrained strength of the reconstituted specimen was less than one fourth of the undisturbed one due to marked difference of dilatancy characteristics of those specimens. The angle of shearing resistance between the pre-existing foliated flakes of serpentinite exhibited 6.5° at minimum.