【摘要】 利用动三轴仪对天津正常固结饱和黏土进行循环剪切试验,重点研究静偏应力与动应力组合作用下土体动变形、动弹性模量及动孔压的变化规律。结果表明静偏应力对黏土循环特性影响显著。静偏应力为0时,土体产生拉应变,其随动应力增加不断增大,量级为10-3。静偏应力大于0时,土体产生压应变,此时若动静应力比小于1,压应变随动应力增加不断增大;若动静应力比大于1,压应变不断减小。相同静偏应力下,动弹性模量随动应力增加不断减小;相同动应力下,动弹性模量随静偏应力增加不断减小,且土体更易发生应变软化。静偏应力为0或为拉时,动孔压在-1~1 kPa范围波动。更多还原

【Abstract】 The cyclic shear tests were performed on the normal consolidated saturated clay from Tianjin with the dynamic triaxial system. The development of the dynamic deformation,the elastic modulus and the pore pressure under the coupled effect of static and dynamic stresses was the focus of the investigation. The test results indicated that the dynamic properties of the soft clay were significantly influenced by the static deviatoric stress. When the static stress σ0 was 0,the tensile strain was generated and increased continuously with the increasing of dynamic stress σd,and the magnitude of the tensile strain was at the scale of 10-3. When the stress was larger than 0,the compressive strain was increased with the increasing of dynamic stress if σd/σ0<1 and decreased if σd/ σ0>1.Under the same static stress, the dynamic elastic modulus decreased with the increasing of dynamic stress.Whereas under the same dynamic stress,the dynamic elastic modulus decreased continuously with the increasing of static stress. Besides, the larger the static stress, the more likely for the strain softening to occur. The pore pressure fluctuated in-1–1 k Pa when the static stress was 0 or tensile.更多还原