Effect of Gradation on the Strength and Stress-Dilatancy of Coarse-Grained Soils: A Comparison of Monotonic Direct Simple Shear and Triaxial Tests
Effect of Gradation on the Strength and Stress-Dilatancy of Coarse-Grained Soils: A Comparison of Monotonic Direct Simple Shear and Triaxial Tests
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DOI：
10.1061/9780784484043.022
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
Rachel Reardon;Francisco Humire;S. S. Ahmed-S.;K. Ziotopoulou;Alejandro Martinez;J. DeJong
中科院分区：
文献类型：
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作者：
Rachel Reardon;Francisco Humire;S. S. Ahmed-S.;K. Ziotopoulou;Alejandro Martinez;J. DeJong
天然沉积物中通常存在各种级配良好的粗粒土，尽管在液化评价中使用基于砂的工程方法对这些材料进行了近似表征。通过31个恒应力直剪和排水三轴压缩试验，研究了平均粒径（D50）和级配（Cu）对粗粒土排水单调强度和应力应变的影响。不同D50和级配的粗粒混合料制备为相对密度为20%-75%，并在一定范围的覆盖层应力下进行测试。结果进行了分析的摩擦阻力和膨胀的贡献，不同级配的土壤的抗剪强度，相比干净的沙子，使用不同的剪切模式。结果表明：（1）由于级配良好的粗粒土具有更大的初始膨胀率，因此增加了土的级配，从而增加了峰值抗剪强度和摩擦阻力;（2）目前的应力-应变关系低估了级配良好的试验材料的膨胀行为。
A broad spectrum of well-graded, coarse-grained soils are commonly present in natural deposits, though characterization of these materials has been approximated using sand-based engineering methods in liquefaction evaluations. Through combined results of 31 constant stress direct simple shear and drained triaxial compression tests, this study experimentally investigates the effect of mean grain size (D50) and gradation (Cu) on the drained monotonic strength and stress-dilatancy of poorly- to well-graded, coarse-grained soils. Coarse-grained mixtures of varying D50and gradations were prepared to relative densities of 20%–75% and tested under a range of overburden stresses. Results are analyzed in terms of the frictional resistance and dilative contributions to the shear strength of soils with varying gradations, as compared to clean sands, using different shearing modes. It is shown that (1) increased gradation of soils increases the peak shear strength and frictional resistance due to a greater initial rate of dilation exhibited in well-graded, coarse-grained soils; and (2) current stress-dilatancy relationships underestimate the dilative behavior of well-graded test materials.