Development of similar materials for fluid-solid coupling model testing and application in damage constitutive...

Area of Science:

• Geotechnical Engineering
• Materials Science
• Rock Mechanics

Background:

• Accurate material selection is crucial for fluid-solid coupling model tests.
• Understanding the mechanical behavior of composite materials under stress and water infiltration is essential for geotechnical applications.

Purpose of the Study:

• To determine optimal material compositions for fluid-solid coupling model tests.
• To investigate the influence of aggregate type and modifiers on material properties.
• To develop a damage constitutive model for rock under triaxial compression with rainwater infiltration.

Main Methods:

• Orthogonal experimental design using iron concentrate powder, barite powder, cement, gypsum, and clay.
• Mechanical property testing including compressive strength, elastic modulus, and cohesion.
• Development of a damage constitutive model based on Weibull statistical damage theory.

Main Results:

• Aggregate type (ATC) significantly controls strength and water absorption; increased ATC ratio decreases these properties.
• Gypsum and cement do not synergistically enhance strength; increased gypsum content (GTC) increases water absorption but decreases softening and permeability coefficients.
• A damage constitutive model was established, showing deviations from experimental results due to pore influence, particularly at higher confining pressures.

Conclusions:

• Material composition, particularly aggregate type and gypsum content, critically influences the mechanical and hydraulic properties of the tested materials.
• The developed damage model effectively describes rock failure under combined load and rainwater infiltration, providing a theoretical basis for slope stability analysis.
• Specific gypsum content (4-16% of cement) is suitable for studying hydraulic properties of sedimentary rock analogs.