Experimental Study on Uniaxial Compression Behavior of Fissured Loess Before and After Vibration

Abstract

Fissured loess is one of the sources of geological hazards such as landslides and collapse under dynamic load. In this study, acrylic pipes with an inner diameter of 62 mm were processed into molds with different inclination angles (α = 0°, 15°, 30°, 45°, 60°, and 90°), and soil samples with preset fissure angles were prepared in two parts, i.e., loess block and weak interlayer. The sample was first vibrated by a test bench with sinusoidal waveform output, followed by uniaxial compression tests to investigate the mechanical properties of fissured loess before and after vibration. Results indicate that the failure mode of fissured loess is independent of the vibration disturbance; four types of failure modes were found after vibration, i.e., compressive fracture failure at α = 0° and 15°, slip failure at α = 60°, slip-fracture coupled failure at α = 45°, and compressive shear failure at α = 30° and 90°. The effect of vibration parameters on the stress–strain curve of fissured loess is mainly reflected in the decrease of both peak strength and initial elastic modulus. U-shaped changes of uniaxial compressive strength were observed in the ranges of 0°–45° and 45°–90°, respectively.