Strength Weakening and Its Micromechanism in Water–Rock Interaction

The water-rock interaction (WRT) is a hot issue in the field of geology and geotechnical engineering. Many geological hazards and engineering safety problems are more significant under the WRT. This chapter focuses on the water weakening on rock strength and its influencing factors (water content, immersion time, wetting-drying cycles). The strength of rock mass decreases in varying degrees with water content, immersion time and wetting drying cycles, which is related to the type of rock mass and mineral composition. The corresponding acoustic emission count and intensity, and the infrared radiation intensity also weakens accordingly. WRI enhances the plasticity of rock mass and reduces its brittleness. Various microscopic methods for studying the pore characterization and weakening mechanism of WRI are compared and analyzed. And it is recommended to adopt various methods to comprehensively study the pore evolution of WRI. With the help of microscopic methods, weakening mechanism of WRI is addressed in this chapter. In future work, the mechanical parameters of rock weakened under long-term water immersion (over years) should be considered, and more attention should be paid to how the laboratory scale is applied to the engineering scale.