数字照相量测在砂土地基离心试验中的应用

Experimental investigation on progressive deformation patterns of sand foundation in centrifuge test using digital photogrammetry

采用数字照相变形量测技术,利用笔者提出的适应岩土局部化变形特点的三步搜索图像分析算法,对砂土地基在离心机和重力场试验中的变形场与变形模式,进行了全面观测与分析,得到了地基的变形范围、滑动面位置与形状、变形局部化和剪切带特征,再现了地基的渐进性变形与破坏的全过程。实验成果可为相关岩土本构模型的建立、检验和改进提供参考依据。

A series of model tests were used to study the bearing capacity of sand foundation in centrifugal and gravitational fields. The global deformation fields in foundation were investigated accurately by the digital photogrammetry and a software package, which incorporated the three-step search algorithm proposed by the authors. The deformation patterns, such as deformation scope, sliding surface, the characteristics of localized deformation, and shear band, were observed accurately. The process of progressive failure in foundation was also captured successfully and analyzed quantitatively. The test results would be beneficial to verify and improve some related numerical constitutional models.