Application of resistivity in the characterization of shear failure process of gas bearing marine silt

Abstract

Gas bearing marine silt is widely distributed in China's offshore areas. The shear failure of gas bearing marine silt may lead to marine engineering geological disasters, such as seabed subsidence and submarine landslides. Monitoring the shear failure process of gassy soil in real time can warn marine geological disasters and ensure the safety of marine engineering. Marine resistivity monitoring has the advantages of a large monitoring range and real time measurement, so it has good application potential. However, the variations in resistivity during the shear failure of gas bearing marine silt are not clear. In this study, we obtained the resistivity changes of gas bearing marine silts during the shear failure process through triaxial experiments combined with resistivity measurements, and we analyzed the factors controlling the resistivity changes. The results show that the shear failure of gas bearing silt samples with different dry densities has stable resistivity characteristics. Moreover, for the two electrical factors in the process of soil shear failure, the evolution of soil cracks and the soil wettability, the change of resistivity is controlled by the change of soil wettability. The failure stage of shear failure can be identified by the change in the resistivity of gas bearing soil.