Experimental Study on Shear Failure Characteristics of Jointed Rock Mass Based on Direct Shear Tests and Digital Image Correction Techniques

The instability of rock engineering is normally dominated by the shear failure of rock mass. The dip angle of discontinuous planes widely existing in rock mass is a key parameter affecting the shear strength and failure mode of jointed rock. This paper aims to investigate the influence of discontinuous joints on the shear failure of rock. Direct shear tests are carried out on rock-like specimens with discontinuous joints in different dip angles. During the shear tests, the strain field is monitored in real-time by digital image correction (DIC) technology. Experimental results show that the shear strength, shear strain evolution, and failure mode for the jointed specimens are affected by the dip angles of the discontinuous joints. The maximum shear strain of specimens with joint angles of 45° and 75° increases gradually with the increase of shear loading. The maximum shear strain for the specimens with joint angles of 0°, 15°, 30°, 60°, and 90° increases sharply after the shear load reaches 80% of the peak load. When the joint inclination angle is less than 45°, the crack begins to expand from the joint tip and is interconnected to form a penetrating fracture. When the joint dip angle is greater than 45°, the cracks initiate at the joint tip and then propagate at different paths resulting in multistage shearing and crushing failure.

[1]  Xun Xi,et al.  Using artificial neural network to predict the fracture properties of the interfacial transition zone of concrete at the meso-scale , 2021 .

[2]  Xun Xi,et al.  Experimental Investigation and Numerical Simulation on the Crack Initiation and Propagation of Rock With Pre-Existing Cracks , 2020, IEEE Access.

[3]  P. Pan,et al.  Fracture analysis of Beishan granite after high-temperature treatment using digital image correlation , 2020 .

[4]  Jiang Xu,et al.  Progressive failure behaviors and crack evolution of rocks under triaxial compression by 3D digital image correlation , 2019, Engineering Geology.

[5]  Shaojun Li,et al.  Fracture analysis of sandstone with a single filled flaw under uniaxial compression , 2018, Engineering Fracture Mechanics.

[6]  Zilong Zhou,et al.  Fracture analysis of marble specimens with a hole under uniaxial compression by digital image correlation , 2017 .

[7]  H. Su,et al.  Mode I fracture behaviour of sandstone after heat treatment , 2017 .

[8]  Xiating Feng,et al.  Do disk-type specimens generate a mode II fracture without confinement? , 2016 .

[9]  Bruce Hebblewhite,et al.  Numerical investigation of the effect of joint geometrical parameters on the mechanical properties of a non-persistent jointed rock mass under uniaxial compression , 2013 .

[10]  张晓平,et al.  MACRO-AND MESO-ANALYSES OF ROCK JOINT DIRECT SHEAR TEST USING PARTICLE FLOW THEORY , 2012 .

[11]  Giovanni Battista Barla,et al.  A Bonded Particle Model Simulation of Shear Strength and Asperity Degradation for Rough Rock Fractures , 2012, Rock Mechanics and Rock Engineering.

[12]  M. Prudencio,et al.  Strength and failure modes of rock mass models with non-persistent joints , 2007 .

[13]  A.P.S. Selvadurai,et al.  Mechanics of a discontinuity in a geomaterial , 2005 .

[14]  H. Kutter,et al.  Breakage and shear behaviour of intermittent rock joints , 2003 .

[15]  W. Peters,et al.  Digital Imaging Techniques In Experimental Stress Analysis , 1982 .

[16]  E. Z. Lajtai.  SHEAR STRENGTH OF WEAKNESS PLANES IN ROCK , 1969 .

[17]  E. Z. Lajtai,et al.  Strength of Discontinuous Rocks in Direct Shear , 1969 .

[18]  Yujing Jiang,et al.  Macro-Micro Failure Mechanisms and Damage Modeling of a Bolted Rock Joint , 2017 .

[19]  Shucai Li,et al.  Numerical analysis and fluid-solid coupling model test of filling-type fracture water inrush and mud gush , 2017 .

[20]  A. Basu,et al.  A Comparison Between the Shear Behavior of ‘Real’ Natural Rock Discontinuities and Their Replicas , 2017, Rock Mechanics and Rock Engineering.

[21]  X. Caichu,et al.  PARTICLE FLOW NUMERICAL SIMULATION FOR SHEAR BEHAVIOR OF ROUGH JOINTS , 2012 .

[22]  Yuan Xiaoshuai.  3D GEOMECHANICAL MODEL FOR PROGRESSIVE FAILURE PROGRESS OF WEAK BROKEN SURROUNDING ROCK IN SUPER LARGE SECTION TUNNEL , 2012 .

[23]  Liu Bo.  STUDY ON STRENGTH BEHAVIORS OF ROCK JOINTS UNDER DIFFERENT SHEARING DEFORMATION VELOCITIES , 2006 .