Strength determination of rocks by using indentation tests with a spherical indenter
Strength determination of rocks by using indentation tests with a spherical indenter
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DOI：
10.1016/j.jsg.2017.03.009
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发表时间：
2017-05
影响因子：
3.1
通讯作者：
M. Kitamura;T. Hirose
中科院分区：
文献类型：
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作者：
M. Kitamura;T. Hirose
我们对四种不同孔隙率（<20%）的岩石类型进行了球形压痕和单轴压缩试验。对于这两种方法，压缩强度都随着孔隙率的降低而增加，但单轴压缩试验（Co）获得的强度低于压痕试验（Ci）获得的强度。我们建立了Co和Ci之间的线性关系，表示为Co=0.513×Ci。两种方法获得的强度差异可能反映了压头下孔隙塌陷造成的相当大的非弹性变形，以及压痕测试中缺乏单轴压缩的横向变形特征。两种方法之间的经验关系将允许将压痕试验的结果转换为与单轴压缩试验获得的结果等效的值。我们将该方法应用于综合海洋钻探计划第 348 次探险期间从南开增生棱体中回收的钻屑。通过压痕试验确定的钻屑的 Co-孔隙度关系与之前报道的通过使用常规压缩实验从圆柱形样本获得的关系一致。该方法可通过从比常规岩石变形实验所需的更小的样本获取数据来表征岩石的力学行为。
We conducted spherical indentation and uniaxial compression tests on four rock types of various porosities (<20%). For both methods, the compressive strength increased with decreasing porosity, but the strength obtained by the uniaxial compression test (Co) was lower than that obtained by the indentation test (Ci). We established a linear relationship betweenCoandCi, expressed byCo= 0.513 ×Ci. The difference in strength obtained by the two methods might reflect a considerable amount of inelastic deformation due to pore collapse under the indenter, and the lack during indentation testing of the lateral deformation characteristic of uniaxial compression. The empirical relationship between the two methods will allow conversion of the results of indentation tests to values equivalent to those obtained from uniaxial compression tests. We applied the method to drill-cuttings retrieved from the Nankai accretionary prism during Integrated Ocean Drilling Program Expedition 348. TheCo–porosity relationship of the cuttings determined by the indentation tests was consistent with the previously reported relationships obtained from cylindrical specimens by using conventional compression experiments. The method can be used to characterize the mechanical behavior of rocks by obtaining data from smaller specimens than those required for conventional rock deformation experiments.