Effects of stress conditions on rheological properties of granular soil in large triaxial rheology laboratory tests

In order to study the rheological properties of red stone granular soil,a series of rheological experiments were executed on large tri-axial rheological apparatus.Under 100,200 and 300 kPa confining stress conditions,the rheological tests were carried out.These experiment results showed that the stress conditions,especially the stress level were the critical influencing factors of the rheological deformation properties.Under the low stress level(S=0.1),the granular soil showed the elastic properties,and there was no obvious rheological deformation.Under the middle stress level(0.20.8) creep curves showed the non-linear viscous plastic rheological properties.Especially,under the stress level of S=1.0,the accelerated rheological phase of creep curves occurred at early time with a trend of failure.The stress level had obvious effects on the final rheological deformation of the soil sample,and the final rheological deformation increments nonlinearly increased with stress level.The final rheological deformation increment and step was little under low stress level,while it became large under high stress level,which showed the nonlinearly rheological properties of the granular soil.The confining pressure also had direct effects on final rheological deformation,and the final rheological deformation linearly increased with confining pressure increments.     

时间因子趋向零时孔隙压力计算中的振荡现象研究

固结过程中孔隙压力的计算结果对于固结度及固结系数的确定均有一定的影响。目前,孔隙压力的计算还仍然采用太沙基提出的级数计算公式,对该公式分析表明,当时间因子较小时,孔隙压力的计算中会出现病态的振荡现象,针对这种病态的振荡现象,采用傅立叶变换,对该计算公式进行变换,计算结果表明,对时间因子较小时,文中提出的计算公式可有效减少太沙基提出的级数计算公式中的这种病态振荡现象,计算结果良好。