The dynamics of a pumice granular soil in dry state under isotropic resonant column testing
The dynamics of a pumice granular soil in dry state under isotropic resonant column testing
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DOI：
10.1016/j.soildyn.2012.11.009
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发表时间：
2013-02
影响因子：
4
通讯作者：
K. Senetakis;A. Anastasiadis;K. Pitilakis;M. Coop
中科院分区：
文献类型：
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作者：
K. Senetakis;A. Anastasiadis;K. Pitilakis;M. Coop
振动下土壤的响应强烈地依赖于颗粒的类型，这反映了颗粒接触的行为和主导颗粒集合体的微观机制。本文研究了低容重、高孔隙度浮石土的动力特性。作为参考土壤，使用了具有硬颗粒的石英质碎石。实验是在固定自由共振柱装置中，在各向同性约束条件下，对砂砾尺寸的干样品进行的。在小应变范围内，Vs-σm′和GO-σm′关系受矿物学和形态学颗粒类型的影响;浮石样品颗粒接触处的塑性响应导致nV和nG指数高于石英样品。浮石和石英土的小应变阻尼比值相当相似，而指数nD的值更分散。在较高的剪切应变幅，浮石土壤表现出更高的线性相比，石英的。这部分归因于在浮石土的动态加载过程中发生的颗粒接触处的微破碎，其将弹性和体积阈值转移到更高的应变，并在颗粒组件的能量耗散中起着重要作用。
The response of soils under vibrations strongly depends on the type of particles which reflects the behavior at particle contacts and the micro-mechanisms that dominate granular assemblies. In this paper the dynamic properties of a pumice soil of low bulk density and high porosity were investigated. As a reference soil, a quartzitic crushed rock with hard particles was used. The experiments were performed on dry samples of sand to gravel size under isotropic conditions of confinement in a fixed-free resonant column apparatus. In the range of small strains, the Vs–σm′ and GO–σm′ relationships are dominated by particle type in terms of mineralogy and morphology; plastic response at particle contacts of the pumice samples led to higher nVand nGexponents in comparison to the quartz ones. The small-strain damping ratio values were fairly similar for pumice and quartz soils, while the values of the exponent nDwere more scattered. At higher shear strain amplitudes, the pumice soils showed higher linearity in comparison to the quartz ones. This is attributed partially to micro-crushing at particle contacts that occurs during the dynamic loading of the pumice soils which shifts the elastic and volumetric thresholds to higher strains and plays an important role in the energy dissipation in granular assemblies.