The deterioration of shear resistance in rock and soil masses has resulted in numerous severe natural disasters, highlighting the significance of long-term monitoring for disaster prevention and mitigation. This study explores the use of a nondestructive method to quickly and accurately evaluate the shear properties of soil-rock mixture. The shear stress, shear strain, and resistivity of the soil-rock mixture were tested simultaneously using a combination of direct shear and resistivity tests. The test results show that the resistivity of the soil-rock mixture gradually decreases with increasing shear strain. The resistivity of all specimens ranged approximately from 60 to 130 Omega.m throughout the shear process. At the end of the shear test, the vertical failure resistivity showed an irregular W shape with increasing rock content. It exhibited a significant negative linear functional relationship with the shear strength. With reference to the determination of cohesion and internal friction angle on the shear strength envelope, the horizontal angle of the vertical failure resistivity-normal stress curve is defined as the resistivity angle, and the intercept of the curve is the resistivity at the initial moment of shear. It has been observed that the resistivity angle is negatively and linearly correlated with the internal friction angle. At the same time, there is a linear growth relationship between resistivity at the initial moment of shear and cohesion. It has been demonstrated that an increase in rock content contributes to a general escalation in both the average structure factor and average shape factor. Meanwhile, a decrease in the anisotropy coefficient has also been noted. These alterations are indicative of the extent of microstructural transformations occurring during the deformation process of the soil-rock mixture. The research results verify the feasibility of real-time deformation monitoring and characterization of shear strength parameters using resistivity.

Studies show that adding carbon fiber to concrete to form a conductive network can make concrete feel its own stress, strain, cracks, and damage according to the change of conductive network, and improve the strength and durability of concrete. In view of the self-sensing characteristics of carbon fiber, carbon fiber reinforced cement-based composites are put forward as a new intelligent sensing material. Through unconfined compressive strength test, resistivity test, microscopic test, and model test, the influence of fiber volume fraction and fiber length on unconfined compressive strength and resistivity change rate of carbon fiber reinforced cement-based composites are studied. A carbon fiber reinforced cement-based composites sensor is made according to the optimal ratio, which is implanted into cement-based composites components to establish the functional relationship between the sensor resistivity change rate and the stress of cement-based composites components, so as to realize the stress monitoring of cement-based composites components by the sensor. The results show that, in the study of the strength of carbon fiber reinforced cement-based composites, the unconfined compressive strength of carbon fiber reinforced cement-based composites is affected by both carbon fiber volume fraction and carbon fiber length, and the compressive strength increases first and then decreases with the increase of both. In the test range, 2% is the optimal volume fraction and 6 mm is the optimal fiber length. In the study of the resistivity change rate of carbon fiber reinforced cement-based composites, when the carbon fiber volume fraction is 1% and the fiber length is 3 mm, the resistivity change rate of the specimen is the largest, and the self-sensing sensitivity of carbon fiber reinforced cement-based composites is the best. There is an obvious exponential relationship between the resistivity change rate of the sensor embedded in the component and the stress of the cement-based composites component. Through establishing a stress prediction formula based on resistivity change rate, the stress state monitoring of the cement-based composites structure can be realized.