本文遵循了一篇参考论文,该论文启发了MDPI的主题“随机地质力学:从实验到正向建模”,从高分辨率边界位移场充分描述了整体和局部变形对砂样的影响,并由其实验数据库支持,这是开放给科学界进一步研究。本文介绍了使用来自此类实验数据库子集的时空统计来表征标本的时空位移场,通过重复一组排水三轴压缩测试来填充,干,真空固结砂试样,在类似的实验控制条件下测试。使用三维数字图像相关(3D-DIC)技术在轴向压缩下的整个剪切过程中测量标本的边界位移场。计算了不同数据维度条件下的时空一阶和二阶统计量(0D,0D-T,1D-T,3D-T)来识别和表征不同测试样本中的主要失效机制。这使我们能够量化定位现象的时空不确定性。结果表明,在不同的维度条件下,沿着变形过程捕获的不确定性可以直接与不同的破坏机制相关联。包括本地化模式,例如剪切的发生和演变,压缩,和扩展乐队。这些时空观测显示了样本表面上局部独特的位移区域之间的依赖性,在试样剪切过程中的不同时间。这项工作的结果提供了沙中实验证据的边界时空统计,为砂土本构特性数值模拟研究的开展奠定了基础。此外,它允许对不确定性对砂子运动学现象的机械解释的影响有新的理解。
This paper follows up on a reference paper that inspired MDPI\'s Topic \"Stochastic Geomechanics: From Experimentation to Forward Modeling\", where global and local deformation effects on sand specimens are fully described from high resolution boundary displacement fields, and supported by its experimental database, which is open to the scientific community for further study. This paper introduces the use of spatio-temporal statistics from a subset of such an experimental database to characterize the specimens\' spatio-temporal displacement fields, populated by repeating a set of triaxial compression tests on drained, dry, vacuum-consolidated sand specimens, tested under similar experimentally controlled conditions. A three-dimensional digital image correlation (3D-DIC) technique was used to measure the specimens\' boundary displacement fields throughout the course of shearing under axial compression. Spatio-temporal first- and second-order statistics were computed for different data dimensionality conditions (0D, 0D-T, 1D-T, 3D-T) to identify and characterize the dominant failure mechanisms across different testing specimens. This allowed us to quantify localization phenomena\'s spatio-temporal uncertainty. Results show that the uncertainty captured along the deformation process across different dimensionality conditions can be directly associated with different failure mechanisms, including localization patterns, such as the onset and evolution of shear, compression, and expansion bands. These spatio-temporal observations show the dependencies between locally distinctive displacement regions over a specimen\'s surface, and across different times during a specimen\'s shearing process. Results of this work provide boundary spatio-temporal statistics of experimental evidence in sands, which sets the basis for the development of research on the numerical simulation of sand\'s constitutive behavior. Moreover, it allows to add a new understanding on the effect of uncertainty on the mechanistic interpretation of sands\' kinematic phenomena.