THE STEADY STATE OF SANDY SOILS
THE STEADY STATE OF SANDY SOILS
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DOI：
10.3208/sandf.36.2_81
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发表时间：
1996-06
影响因子：
3.7
通讯作者：
R. Verdugo;K. Ishihara
中科院分区：
文献类型：
--
作者：
R. Verdugo;K. Ishihara
介绍了一种估算三轴试样孔隙比的方法。特别是当测试非常松散的样品时，并且预计在饱和过程中会发生重要的体积变化时，建议使用此方法。此外，使用丰浦砂一套全面的三轴试验进行了不排水和排水条件下的单调加载。对于不排水收缩反应，结果显示与稳态相关的两个阶段。在峰值强度之后，偏应力下降到一个最小值，这可以看作是一个准稳定状态，此后，强度增加到一个极限值对应于实际的稳定状态。不排水膨胀反应清楚地表明存在一个极限状态发展在大变形，这代表了稳定状态的变形。结果表明，初始平均应力对准稳态影响不大，而对稳态影响不大。此外，通过排水加载条件下达到的极限状态的轨迹与不排水试验评估的稳定州线一致。最后，根据稳定州线相对于松散和松散状态下各向同性固结曲线的相对位置，提出了相对收缩性指标Rc。据推测，Rc与土壤的固有液化脆弱性有关。
An alternative procedure to evaluate the void ratio of triaxial test samples is introduced. This method is recommended particularly when very loose samples are tested and an important volume change occurring during the saturation process is expected. In addition, using Toyoura sand a comprehensive set of triaxial tests carried out under both undrained and drained conditions of monotonic loading is presented. For the undrained contractive responses, the results showed two stages associated with the steady state. After the peak strength, the deviator stress drops to a minimum value which can be seen as a quasi steady state, thereafter, the strength increases to an ultimate value corresponding to the actual steady state. Undrained dilative responses clearly indicated the existence of an ultimate state developed at large deformations which represents the steady state of deformation. The results indicate that the quasi steady state is slightly affected by the initial mean stress, whereas, the steady state is unaffected by the initial mean stress. Furthermore, the locus of the ultimate states achieved through drained conditions of loading was shown to be coincident with the steady state line evaluated by means of undrained tests. Finally, according to the relative position of the steady state line with respect to the isotropic consolidation curves for the loosest and densest states of a given soil, the index, Relative Contractiveness, Rc, is proposed. It is postulated that Rc is related to the inherent liquefaction vulnerability of a soil.