Shear mechanisms and viscoplastic effects during impulsive shearing

被引:25
作者
Grelle, G. [1 ]
Guadagno, F. M. [1 ]
机构
[1] Univ Sannio, Dept Geol & Environm Studies, Benevento, Italy
来源
GEOTECHNIQUE | 2010年 / 60卷 / 02期
关键词
clays; impulsive shear strength; landslides; viscoplastic behaviour; DRAINED RESIDUAL STRENGTH; DEFORMATION CHARACTERISTICS; COHESIVE SOILS; CLAYS; GEOMATERIALS; EARTHQUAKES; LANDSLIDES; BEHAVIOR;
D O I
10.1680/geot.8.P.019
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
In clay formations, the co-seismic reactivation of preexisting landslides involves dynamic shear actions on sliding surfaces characterised by attritive states. Impulsive shear motions were applied, after the attainment of the fully softened and residual conditions, by means of an appropriately modified ring-shear apparatus. The kinematics parameters that characterise shear motions are related to co-seismic displacements of rigid landslide bodies, as defined by Newmark's approach. The results of the tests, performed on clay samples with different index properties, highlight the influence of the initial spatial disposition of particles on the shear mechanisms. In addition, it seems that these mechanisms control both the inviscid and viscous components of the shear stress. For high shear rates, an increase of the viscous strength in the residual condition determines a greater viscoplastic strength than that in the fully softened condition. On this basis, different behaviours in seismically induced reactivation of landslides can be explained.
引用
收藏
页码:91 / 103
页数:13
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