Fracture behaviour of central-flawed rock plate under uniaxial compression

Abstract Fault fracture zone is a common engineering geological condition in mountain tunnel excavation, which often brings great difficulties to engineering construction. Thus, uniaxial compression experiments were carried out on the granite specimens with a central hole and hole edge flaws to investigate such engineering problems. And the crack initiation mechanism was studied by theoretical analysis and Extended Finite Element Methods (XFEM) simulation. The experimental results show that the mechanical parameters and crack types of the specimens distinctly vary with the flaw inclination. The mechanical properties of specimens such as strength are greatly weakened by the central hole and hole edge flaws compared with those of intact specimens, and the weakening effect decreases gradually with the increase of flaw inclination angle. When the inclination angle of flaw is small, the proportion of tensile cracks is high, resulting in tensile failure of specimens. While as the inclination angle of flaw increases, shear cracks gradually dominate, leading to shear failure in the specimen. In addition, the results of theoretical analysis and numerical simulation show that the wing crack initiation angle that appeared in the experiment are completely consistent with the theoretical and simulation results. And it is suggested by numerical results that the tensile stress at the flaw tip of specimens with flaw inclination angle of 15° and 75° is lower than that of other specimens, which may cause the absence of wing cracks.

[1]  Herbert H. Einstein,et al.  Fracture coalescence in rock-type materials under uniaxial and biaxial compression , 1998 .

[2]  X. Fan,et al.  Influence of single flaw on the failure process and energy mechanics of rock-like material , 2017 .

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

[4]  N. Muskhelishvili.  Some basic problems of the mathematical theory of elasticity , 1953 .

[5]  Ruben Juanes,et al.  Numerical modeling of the transient hydrogeological response produced by tunnel construction in fractured bedrocks , 2002 .

[6]  Antonio Bobet,et al.  Crack initiation, propagation and coalescence from frictional flaws in uniaxial compression , 2010 .

[7]  Sheng-Qi Yang,et al.  Strength failure and crack coalescence behavior of brittle sandstone samples containing a single fissure under uniaxial compression , 2011 .

[8]  Kourosh Shahriar,et al.  Cracks coalescence mechanism and cracks propagation paths in rock-like specimens containing pre-existing random cracks under compression , 2014 .

[9]  F. Erdogan,et al.  On the Crack Extension in Plates Under Plane Loading and Transverse Shear , 1963 .

[10]  Lianyang Zhang,et al.  Cracking and Stress–Strain Behavior of Rock-Like Material Containing Two Flaws Under Uniaxial Compression , 2016, Rock Mechanics and Rock Engineering.

[11]  Ping Cao,et al.  Mechanical Behavior of Brittle Rock-Like Specimens with Pre-existing Fissures Under Uniaxial Loading: Experimental Studies and Particle Mechanics Approach , 2016, Rock Mechanics and Rock Engineering.

[12]  A. Brogi.  Fault zone architecture and permeability features in siliceous sedimentary rocks : Insights from the Rapolano geothermal area (Northern Apennines, Italy) , 2008 .

[13]  Seokwon Jeon,et al.  An experimental and numerical study of fracture coalescence in pre-cracked specimens under uniaxial compression , 2011 .

[14]  X. Zhuang,et al.  A comparative study on unfilled and filled crack propagation for rock-like brittle material , 2014 .

[15]  F. V. Antunes,et al.  Finite element modelling and analysis of crack shape evolution in mode-I fatigue Middle Cracked Tension specimens , 2008 .

[16]  Mostafa Sharifzadeh,et al.  A bonded particle model for analysis of the flaw orientation effect on crack propagation mechanism in brittle materials under compression , 2014 .

[17]  A. Bobet.  The initiation of secondary cracks in compression , 2000 .

[18]  Peng Lin,et al.  Experimental and numerical study on splitting failure of brittle solids containing single pore under uniaxial compression , 2006 .

[19]  L. Wong,et al.  Cracking Processes in Rock-Like Material Containing a Single Flaw Under Uniaxial Compression: A Numerical Study Based on Parallel Bonded-Particle Model Approach , 2011, Rock Mechanics and Rock Engineering.

[20]  Ping Cao,et al.  Crack propagation and coalescence of brittle rock-like specimens with pre-existing cracks in compression , 2015 .

[21]  Yuqing Cao.  Three-dimensional finite element modeling of subsurface median crack in trilayer sandwiches due to contact loading , 2002 .

[22]  Ming Cai,et al.  Generalized crack initiation and crack damage stress thresholds of brittle rock masses near underground excavations , 2004 .

[23]  Antonio Bobet,et al.  Crack coalescence in specimens with open and closed flaws: A comparison , 2009 .

[24]  Da’an Liu,et al.  Hydraulic fracturing test with prefabricated crack on anisotropic shale: Laboratory testing and numerical simulation , 2018, Journal of Petroleum Science and Engineering.

[25]  H. Su,et al.  Investigation on mechanical behavior and crack coalescence of sandstone specimens containing fissure-hole combined flaws under uniaxial compression , 2018, Geosciences Journal.

[26]  Rihong Cao,et al.  The stability and roof-support optimization of roadways passing through unfavorable geological bodies using advanced detection and monitoring methods, among others, in the Sanmenxia Bauxite Mine in China’s Henan Province , 2019, Bulletin of Engineering Geology and the Environment.

[27]  Louis Ngai Yuen Wong,et al.  Systematic evaluation of cracking behavior in specimens containing single flaws under uniaxial compression , 2009 .

[28]  Baiquan Lin,et al.  Mechanical behaviors and failure processes of precracked specimens under uniaxial compression: A perspective from microscopic displacement patterns , 2016 .

[29]  R. Wong,et al.  Coalescence of two parallel pre-existing surface cracks in granite , 2014 .

[30]  S. Du,et al.  An empirical statistical constitutive relationship for rock joint shearing considering scale effect , 2019, Comptes Rendus Mécanique.

[31]  J. Johansson,et al.  Fault induced permanent ground deformations: Experimental verification of wet and dry soil, numerical findings’ relation to field observations of tunnel damage and implications for design , 2007 .

[32]  Antonio Bobet,et al.  Coalescence of multiple flaws in a rock-model material in uniaxial compression , 2002 .

[33]  X. Fan,et al.  Cracking and Failure in Rock Specimen Containing Combined Flaw and Hole under Uniaxial Compression , 2018 .

[34]  Rihong Cao,et al.  Determination of the stress field and crack initiation angle of an open flaw tip under uniaxial compression , 2019 .

[35]  S. Jeon,et al.  Effect of a fault and weak plane on the stability of a tunnel in rock—a scaled model test and numerical analysis , 2004 .

[36]  Kevin Z. Truman,et al.  An evaluation of fracture mechanics quarter-point displacement techniques used for computing stress intensity factors , 1999 .

[37]  Quanle Zou,et al.  Cracking Process and Stress Field Evolution in Specimen Containing Combined Flaw Under Uniaxial Compression , 2016, Rock Mechanics and Rock Engineering.

[38]  Herbert H. Einstein,et al.  Cracking processes in Barre granite: fracture process zones and crack coalescence , 2013, International Journal of Fracture.

[39]  Z. Li,et al.  Crack Propagation and Coalescence of Step-Path Failure in Rocks , 2018, Rock Mechanics and Rock Engineering.