Experimental and Numerical Study of the Failure Behavior of Intermittent Rock Joints Subjected to Direct Shear Load

Abstract

Two series of intermittent rock joints containing three joints arranged along the central shear axis were considered in this study. e failure behavior under direct shear loads was investigated by means of both physical tests and numerical simulations. e cracking behavior was found to be distinctly associated with the joint arrangement. Several types of main and secondary cracks were identified. e variation trends of the crack initiation stress ratio with inclination angle were analyzed and found to be partly different for the two series of intermittent joints. e whole fracturing process was characterized by three phases. Not all samples have to experience all three phases. e second phase is alternative and can be reflected by the shearing curve. Hence, two types of shearing curves, including single and double peaks, were identified. e double peak is due to the extrusion or sawteeth cutting in the second phase. Moreover, the numerical micromechanical analysis was performed to explain the shear behavior using the contact force and microcrack within the specimen. Based on the numerically measured local stresses, maximum and minimum principal stresses around the middle joint at crack initiation stress and peak shear stress were analyzed.

Analysis of Stress and Deformation Characteristics of Deep‐Buried Phyllite Tunnel Structure under Different Cross‐Section Forms and Initial Support Parameters

“…e rock samples taken from the field site were made into slices, which were then placed under a polarizing microscope to observe the mineral composition of the rock samples [31][32][33][34]. e compositions of the rock samples are detailed in Table 1.…”

The Coupled Control of Floor Heave Based on a Composite Structure Consisting of Bolts and Concrete Antiarches

“…Moreover, the C20 concrete with the elastic modulus, tensile strength, compressive strength, cohesion, and frictional angle of 25.5 GPa 1.1 MPa, 9.6 MPa, 2.0, and 45 ∘ , respectively, was applied to fabricate the concrete arches [25]. Considering the construction infeasibility at the corner between the floor and the sidewalls, the elastic modulus of the concrete antiarch layer with a thickness of 0.3 m was = 10 GPa [24,26].…”

Numerical Analyses of Fracturing Behavior and Strength of Specimens with Two Parallel Infilled Flaws under Uniaxial Compression

“…e main objective of this study is to analyze the mechanical behavior of grouted samples by observing microcrack development and to obtain the influence of flaw geometry and flaw spatial distribution on the mechanical behavior of rock masses with infilled flaws. e discrete element method (DEM) is widely used for simulating crack propagation in samples with single or multiple flaws [16][17][18][19][20][21][22][23].…”