Canadian Geotechnical Journal, Ahead of Print.
This study addresses the microfabric evolution of coral sand during earthquake-induced liquefaction using the joint tests of macroscopic shaking table and microscopic X-ray computed tomography. Based on the non-destructive scanning and image reconstruction in three-dimensional, the change in the grain–pore structure of sands under earthquakes is discussed. Furthermore, the special microstructural evolution of coral sand is studied by the contrast tests with Fujian sand. The results show that the coordination number of coral sand is larger than that of Fujian sand after liquefaction, which is consistent with that the reduction in acceleration of coral sand is smaller than that of the Fujian sand, and the coral sand foundation still has a larger shear strength due to the smaller excess pore pressure accumulation. Moreover, the contact index of Fujian sand and Reigate sand fluctuates in a similar range with the change of void ratio and coordination number compared with coral sand. This is due to the fact that the Fujian sand and Reigate sand are both general terrigenous sands (quartz sand), while coral sand has irregular particle shapes and larger surface friction caused by marine biogenesis. The test results deepen the understanding of the liquefaction mechanism of coral sand.

中文翻译：

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地震液化过程中珊瑚砂宏观响应与微观结构演化联合分析

加拿大岩土工程杂志，印刷前。
本研究通过宏观振动台和微观 X 射线计算机断层扫描的联合测试，研究了地震引起液化过程中珊瑚砂的微观结构演化。基于三维无损扫描和图像重建，探讨了地震作用下砂粒孔隙结构的变化。并通过与福建砂的对比试验，研究了珊瑚砂特殊的微观结构演化。结果表明，液化后珊瑚砂的配位数大于福建砂，这与珊瑚砂的加速度减小幅度小于福建砂一致，珊瑚砂地基仍具有较大的由于较小的超孔隙水压力积累而产生的抗剪强度。而且，与珊瑚砂相比，福建砂和赖盖特砂的接触指数随着空隙率和配位数的变化在相似的范围内波动。这是因为福建砂和赖盖特砂都是一般的陆源砂（石英砂），而珊瑚砂由于海洋生物成因，颗粒形状不规则，表面摩擦力较大。测试结果加深了对珊瑚砂液化机理的认识。