Experimental study on mechanical properties of fissured loess under true triaxial conditions

Fissured loess is one of the important factors that cause geological disasters in the Loess Plateau. This paper analyzes the mechanical characteristics of fissured loess under different confining pressures and different intermediate effective principal stress coefficients b-values by conducting true triaxial tests on fissured loess with different fracture angles. The results show that there are "Concave Points" in the peak stress curves of the fracture loess samples with different angles, and the "Concave Points" are affected by both intermediate effective principal stress coefficients b-values and confining pressure. When the confining pressure is 100 kPa, the major effective principal stress growth rate K-value increases the most under different intermediate effective principal stress coefficients b-values, and the change trend is basically the same, and the major effective principal stress growth rate K-value growth rate decreases with the further increase of confining pressure. The internal friction Angle of the fusible loess sample is not affected by the change of joint and joint dip Angle; With the same intermediate effective principal stress coefficients b-values, the cohesion increases first, then decreases and then increases with the increase of crack Angle. When the fracture Angle is the same, the cohesion approximately increases with the increase of intermediate effective principal stress coefficients b-values. The 0° crack has the greatest influence on cohesion, the 60° crack has the second, and the 30° and 90° crack has the least influence on cohesion.