Sıkıştırılmış zemin örneklerinin hacimsel özelliklerinin görüntü temelli üç boyutlu yeniden yapılandırma tekniği ile belirlenmesi

The main purpose of this study is to introduce a noncontact and nondestructive methodology to determine the volumetric properties of soil specimens using multi-image 3D reconstruction technique. The 3D solid model of compacted soil specimens was generated with captured 2D images taken from different perspectives using a computational technique called Structure from Motion (SfM). This technique uses multiple overlapping photos of the same object from different perspectives to generate 3D reconstruction. A cylindrical shaped calibration object was produced by a high precision mechanical lathe tool for the validation of the proposed technique. The SfM method and the Archimedes test setup were verified for regular shaped solid calibration object by obtaining 0.02% and -0.047% relative errors in volume with respect to production dimensions. After validating the digital nondestructive methodology, the shrinkage behavior of four types of soil, having low to high expansive characteristics were investigated by both 3D reconstruction technique and conventional Vernier caliper measurement method. Moreover, the proposed technique has been adopted to determine the volume and the bulk density of irregular shaped bulk soil specimens. Irregular shaped soil specimens were obtained by crushing the compacted soil specimens, which compaction energy and molding water content arranged as to have various matrix suction values. The results are compared with wax coating method and verified by Archimedes principle. Considering time consumed in conventional wax coating method and inherent health risks, the implemented method in this study offered a nondestructive way to obtain accurate volumetric properties for irregular shaped soil specimens.