Modeling the Progressive Failure of Jointed Rock Slope Using Fracture Mechanics and the Strength Reduction Method

The fracturing process during the progressive failure of a jointed rock slope is numerically investigated by using fracture mechanics and the strength reduction method (SRM). A displacement discontinuity method containing frictional elements is developed for the calculation of the stress intensity factor (SIF). The failure initiation of the jointed rock slope is analyzed by evaluating the SIF. A new joint model is proposed by combining solid elements with interface elements in the commercial software FLAC3D. These represent the discontinuous planes in a rock mass on which sliding or separation can occur. The progressive failure process is simulated by reducing the shear strength of the rock mass, which includes the process of stress concentration, crack initiation, crack propagation, slip weakening, and coalescence of failure surfaces. The factor of safety (FS) and location of the critical failure surface are determined by the SRM. The influence of the joint inclination is investigated using the FS and the SIF. Laboratory experiments on specimens containing an inclined flaw under compression-shear stress are also conducted to investigate the effect of the angle between the shear direction and the flaw inclination, which provides an experimental explanation for the shear behavior of jointed rock. The results show that the joint inclination dominates the failure behavior of jointed rock slope, and two failure patterns have been classified.

[1]  Zhang Jian.  Study of stress and displacement fields in centrifuge modeling of slope progressive failure , 2008 .

[2]  Musharraf Zaman,et al.  Thin‐layer element for interfaces and joints , 1984 .

[3]  Mark S. Diederichs,et al.  A new model for large landslides in sensitive clay using a fracture mechanics approach , 2011 .

[4]  Thomas M. Tharp,et al.  Field Application Of Fracture Mechanics Analysis To Small Rock Slopes , 1985 .

[5]  G. Ma,et al.  Modeling progressive failures in rock slopes with non‐persistent joints using the numerical manifold method , 2014 .

[6]  K. Yin,et al.  Mechanism of the Anlesi landslide in the Three Gorges Reservoir, China , 2009 .

[7]  Hasan Hosseini Nasab,et al.  On the uses of special crack tip elements in numerical rock fracture mechanics , 2006 .

[8]  G. Exadaktylos,et al.  The G2 constant displacement discontinuity method – Part II: Solution of half-plane crack problems , 2010 .

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

[10]  S. L. Crouch.  Solution of plane elasticity problems by the displacement discontinuity method. I. Infinite body solution , 1976 .

[11]  J. Curran,et al.  Limits of Applicability of the Finite Element Explicit Joint Model In the Analysis of Jointed Rock Problems , 2010 .

[12]  P. Cao,et al.  Progressive failure analysis of slope with strain-softening behaviour based on strength reduction method , 2013 .

[13]  Doug Stead,et al.  Realistic simulation of rock slope failure mechanisms: the need to incorporate principles of fracture mechanics , 2004 .

[14]  Wancheng Zhu,et al.  Numerical analysis of slope stability based on the gravity increase method , 2009 .

[15]  M. Popescu.  Boundary element methods in solid mechanics , 1985 .

[16]  A. Robertson.  interpretation of geological factors for use in slope theory , 1970 .

[17]  W. B. Wei,et al.  Three-dimensional slope failure analysis by the strength reduction and limit equilibrium methods , 2009 .

[18]  J. Douglas Faires,et al.  Numerical Analysis , 1981 .

[19]  Zongqi Sun,et al.  Shear fracture (Mode II) of brittle rock , 2003 .

[20]  H. Q. Zhang,et al.  Numerical study of shear behavior of intermittent rock joints with different geometrical parameters , 2006 .

[21]  Ping Cao,et al.  Numerical simulation of a layered rock under triaxial compression , 2013 .

[22]  John M Kemeny,et al.  The Time-Dependent Reduction of Sliding Cohesion due to Rock Bridges Along Discontinuities: A Fracture Mechanics Approach , 2003 .

[23]  M. Fournier.  Investigations into the Shear Strength Reduction method using distinct element models , 2008 .

[24]  A. Drescher,et al.  Slope stability analysis by strength reduction , 1999 .

[25]  D. Maugis,et al.  Stresses and displacements around cracks and elliptical cavities : exact solutions , 1992 .

[26]  Richard Craswell.  On the uses of , 1993 .

[27]  Dwayne D. Tannant,et al.  Numerical analysis of the stability of heavily jointed rock slopes using PFC2D , 2003 .

[28]  F. Donze,et al.  PROGRESSIVE FAILURE MECHANISMS IN JOINTED ROCK : INSIGHT FROM 3 D DEM MODELLING , 2011 .

[29]  Diederichs,et al.  Shear Strength Reduction Approach For Slope Stability Analyses , 2007 .

[30]  R. Lewis,et al.  Associated and non-associated visco-plasticity and plasticity in soil mechanics , 1975 .

[31]  J. Miller.  Numerical Analysis , 1966, Nature.

[32]  M. H. Freitas.  Rock slope engineering Rock slope engineering , 1984 .

[33]  A. Ghazvinian,et al.  Determination of Sliding Path in Rock Slopes Containing Coplanar Non-Persistent Open Discontinuity , 2008 .

[34]  D. V. Griffiths,et al.  SLOPE STABILITY ANALYSIS BY FINITE ELEMENTS , 1999 .

[35]  E. G. Richard,et al.  A model for the mechanics of jointed rock , 1968 .

[36]  Y. M. Cheng,et al.  Two-dimensional slope stability analysis by limit equilibrium and strength reduction methods , 2007 .

[37]  Doug Stead,et al.  Numerical analysis of initiation and progressive failure in natural rock slopes—the 1991 Randa rockslide , 2004 .

[38]  Erling Nordlund,et al.  Shear box testing and modelling of joint bridges , 1990 .

[39]  R. E. Hammah,et al.  The Practical Modelling of Discontinuous Rock Masses with Finite Element Analysis , 2008 .

[40]  K. Terzaghi,et al.  Stability of Steep Slopes on Hard Unweathered Rock , 1962 .

[41]  Claudio Scavia,et al.  Fracture mechanics approach to stability analysis of rock slopes , 1990 .

[42]  Gregory B. Baecher,et al.  The effect of discontinuity persistence on rock slope stability , 1983 .

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

[44]  Leandro R. Alejano,et al.  Ground reaction curves for tunnels excavated in different quality rock masses showing several types of post-failure behaviour , 2009 .

[45]  Ted Belytschko,et al.  Continuum Theory for Strain‐Softening , 1984 .

[46]  Ping Cao,et al.  Directly searching method for slip plane and its influential factors based on critical state of slope , 2009 .