Collection of data files used in the paper titled: Mechanisms of root-reinforcement in soils: an experimental methodology using four-dimensional X-ray computed tomography and digital volume correlation. Additional dataset which covers the noise study CT scans and digital volume correlation noise studies can be found in DOI: 10.5281/zenodo.3361832 Data contains the following: X-ray CT data for the interrupted direct shear tests of a soil sample containing a Willow plant. The first file is the specimen scanned unloaded, followed by seven incremental shear load steps to 20 mm shear displacement. Files are 8-bit unsigned and 1800x1800x1600px. Voxel resolution is 0.04642 mm. 20180430_HUTCH_1839_DJB_willow_C_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_A_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_B_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_C_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_D_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_E_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_F_8-bit_1800x1800x1600.raw 20180430_HUTCH_1839_DJB_willow_C_Load_G_8-bit_1800x1800x1600.raw Direct shear vs. displacement data is presented in an Excel spreadsheet: All_load_data_with_reducing_area.xlsx Normal and shear strain DVC data which has been averaged and plotted against specimen depth is presented in an Excel spreadsheet: Average_slice_vs_depth_data_all_samples_all_loads3.xlsx CT scan metadata giving information to the scan settings, voxel resolution, etc. is contained in a .zip file which consists of .xtekct and .XML files generated from the Nikon CT scanner. CT_Scan_Metadata.zip Drawings and Solidworks CAD files of the direct shear test rig are contained within the .zip file. There are a number of parts to the assembly. The file SSSB1003-5.SLDASM contains the complete assembly of the direct shear rig and will help identify the part names. The folder CAD_Drawings contains pdf documents of the part drawings. Direct_Shear_Drawings_Solidworks_Files.zip Tabulated DVC data taken at 32x32x32px subset size is contained inside a .zip file. These consist of tab separated .dat files from unloaded (data_1.dat) through incremental load steps Load A, Load B... Load G, (data_2.dat, data_3.dat... data_8.dat). The structure of the .dat file contains columns of data with each column number corresponding to the following: (1) x, (2) y (3) z, (4) vx, (5) vy, (6) vz, (7) exx, (8) eyy, (9) ezz, (10) exy, (11) exz, (12) eyz, (13) volumetric strain, (14) is valid. Columns 1-3 are subset positions in mm, 4-6 are displacements in mm, 7-9 are normal strains, 10-12 are shear strains, 13 is volumetric strain and 14 is a binary value indicating if the subset is valid. DVC_Load_Data_Willow_C.zip Tabulated DVC data applied to the load step CT data at 32, 48, 64, 96, 128 pixels is presented in the .zip files containing .dat tab separated files. The structure of the .dat files is described in the previous bullet point. These files were used to construct the noise study applied to incrementally loaded CT data by sampling regions away from the shear zone where the strain signals are close to zero. DVC_Noise_Study_Data_Load_Steps_Willow_C.zip Processed noise study data which compares the effects of DVC subset size is presented in the .xlsx file. This file contains both the controlled noise experiment data (stationary, magnification and rigid body motion) and noise study data applied to incrementally loaded data using sampled regions away from the shear zone where the strain signals are close to zero. Willow_C_Processed_Noise_study2.xlsx Tabulated data which compares the local x displacement vs depth profile from DVC and direct measurement of root position is contained in the following Excel spreadsheet file: X_Displacement_Root_and_DVC_Comparison_Willow C.xlsx