圆柱孔破损膨胀土扫描数据的三维重建研究

On 3D Reconstruction for CT Images of Cylindrical Hole Damage Expansive Soils

运用多功能CT-三轴仪对三轴剪切试验过程中的土体断层进行扫描,得到了土体断层不同试验阶段的CT图片.从这些扫描图片中提取试样的ME值(平均密度)、SD值(不均匀程度)、试样横断面面积、孔洞面积等信息.运用MATLAB软件对这些信息进行三维立体建模,得到了试验过程中土体不同阶段的三维立体模型.这些三维立体模型反映了土体在剪切过程中整体结构和内部结构的演变情况,解决了以往CT-三轴试验只能从二维角度研究土体结构演变的问题.重建结果表明:三维立体模型对土体整体和内部结构以及各种孔径的变化规律反映得更准确;三维切片可以反映试样断面的演变,有助于我们在三轴剪切过程中更详细地了解试样内部结构的演化规律;经观察发现,不同圆柱孔破损面积对试样剪切过程中试样和孔洞的结构演化形式存在影响.

CT technology has been used to scan the triaxial test samples ,and numerous 2D CT images at different sections obtained .Extracting the information of mean value （ME） ,standard daviation （SD） and the area of the aperture from the images .With those images and MATLAB ,programmed to achieve 3D images at different stages during the test .3D images show the samples internal damage＇s 3D dynamic evo-lution during the loading procedure ,w hich made a breakthrough that can only analyze plane structure evo-lution previously .Results show that 3D reconstruction model we build could observe and measure the soil structure evolution characteristics under different conditions more intuitive ;particularly ,it＇s more accu-rate at describing the sample holes＇ evolution regulation ;3D section can reflects the evolution of the frac-ture surface that contributes to us to understand the sample internal structure evolution＇s regulation during triaxial shearing experiment in more details .Furthermore ,different cylindrical hole area has some influ-ence on the form of holes＇ structure evolution in shearing process .