数字图像测量技术在土工三轴试验中的应用研究

Application of digital image processing technique to triaxial test in soil mechanics

将数字图像处理技术应用于土工三轴试验土样变形测量,提供了一种新的非接触变形测量手段。可消除传统三轴系统的变形测量误差,可测量土样任意部分的局部变形、剪切带的形成和发展过程,可定量分析橡皮膜嵌入的影响,还可实时跟踪并纪录土样变形过程。文中讨论了图像测量结果与传统测量结果的差别,指出对于标准的小三轴试样可以取中间40 mm左右的试样段进行变形测量以排除端部效应影响。

A new means with digital image processing technique for deformation measuring of soil specimen in triaxial test is provided. Using this technique, the error of the deformation measurement, which occurs in traditional triaxial test, can be eliminated. The local deformation of any part of the soil specimen can be measured at will. The coming into being and development of shear bands of the specimen can also be determined. The influence of membrane penetration in the test can be analyzed quantitatively. Meanwhile, the deformation process of the soil specimen can also be tracked and recorded. Comparison of the results by digital image processing technique and by traditional method shows that the former is more accurate. It is indicated that for standard small specimen, measuring the middle 40mm part＇s deformation can get rid of the influence of the end on the deformation.