The shear mechanical properties of rocks with variable angle joints.

Area of Science:

• Geotechnical Engineering
• Materials Science

Background:

• Variable-angle joints in slopes are common but often oversimplified in analysis.
• Previous studies failed to capture the full mechanical properties of variable-angle surfaces.

Purpose of the Study:

• To analyze the mechanical properties of concrete joint specimens with variable angles.
• To investigate the strength, deformation, and failure characteristics under varying normal stresses.

Main Methods:

• Fabrication of concrete joint specimens with variable angles.
• Direct shear tests conducted under different normal stress conditions.
• Analysis of experimental data and comparison with theoretical models.

Main Results:

• Peak shear strength and shear stiffness showed a positive correlation with normal stress.
• Normal and tangential displacements were negatively correlated.
• Distinct failure modes observed in high-angle (vertical and shear cracks) and low-angle zones (shear damage).

Conclusions:

• Variable-angle joints exhibit zonal shear failure patterns.
• Findings offer a theoretical foundation for analyzing the stability of variable angle structural surfaces.