Experimental data on deformation and seepage of grouted fractured sandstone under confining-pressure unloading

This dataset provides experimental data supporting the study of deformation and seepage responses of grouted fractured sandstone under confining-pressure unloading. The experiments were conducted under different axial stress levels (20–60 MPa) and fluid pressures (4, 8, and 12 MPa), with an initial confining pressure of 10 MPa. The dataset includes the experimental measurements and processed results used to analyze axial deformation, fluid seepage, flow-rate evolution, stress–strain behavior, and failure conditions during unloading. It also supports the quantitative evaluation of the effective critical stress ratio (R_c') and the interpretation of hydro-mechanical failure mechanisms. These data are associated with the manuscript submitted to the European Journal of Environmental and Civil Engineering. They are provided to facilitate data verification, reproducibility, and further research on hydro-mechanical behavior and instability of grouted fractured rock.