The dynamic behaviors of calcareous sand were investigated under undrained conditions using cyclic triaxial tests, and the results were compared with those of commercially available Fujian (Fj) sand. The test results were used to evaluate the effects of gradation, particle crushing, and other parameters on the liquefaction resistance. The results of the undrained cyclic triaxial tests indicate that the liquefaction resistance of the well-graded calcareous sand specimens is higher than that of the poorly graded and gap-graded specimens and that the excess pore pressure ratio of calcareous sand cannot reach 1.0. Furthermore, calcareous sand has a much higher liquefaction resistance than Fj sand; this difference is due to the different particle structures and compositions of the two sand types. The particle breakage of calcareous sand was clearly observed after the experiments. To explore this further, the microscopic structure of the calcareous sand was investigated by computed tomography (CT), and inner pores were observed in the calcareous sand particles. A relationship between the liquefaction resistance and particle crushing was determined, which provides direct evidence to explain the process of desaturation observed in some cases.

利用循环三轴试验研究了钙质砂在不排水条件下的动力学行为，并将其结果与市售的福建（Fj）砂进行了比较。测试结果用于评估灰度，颗粒破碎和其他参数对抗液化性的影响。不排水循环三轴试验的结果表明，分级良好的钙质砂试样的耐液化性高于分级不佳和间隙分级的砂岩的耐液化性，钙质砂的超孔隙压力比不能达到1.0。此外，钙质砂的抗液化性比Fj砂高。这种差异是由于两种砂类型的颗粒结构和组成不同而引起的。实验后清楚地观察到钙质砂的颗粒破裂。为了进一步探索这一点，通过计算机断层扫描（CT）研究了钙质砂的微观结构，并在钙质砂颗粒中观察到内部孔隙。确定了抗液化性和颗粒破碎之间的关系，这提供了直接的证据来解释在某些情况下观察到的去饱和过程。