Author/Authors :
Yavari, Mohammad Davood Department of mining Engineering - Bafgh Branch Islamic Azad University, Bafgh, Iran , Haeri Hadi State Key Laboratory for Deep GeoMechanics and Underground Engineering, Beijing, China , Sarfarazi, Vahab Department of Mining Engineering - Hamedan University of Technology, Hamedan, Iran , Fatehi Marji, Mohammad Mine Exploitation Engineering Department - Faculty of Mining and Metallurgy - Institution of Engineering, Yazd University, Yazd, Iran , Lazemi, Hossain Ali Department of mining Engineering - Bafgh Branch Islamic Azad University, Bafgh, Iran
Abstract :
The propagation mechanism of cracks emanating from two holes within the concrete
specimens is studied by considering the effects of different lateral compressive
stresses. The experimental part of this research work is carried out on some specially
prepared pre-cracked specimens with two neighbouring holes under only a uniaxial
compression in the laboratory. The numerical modeling part is performed under both
the uniaxial compresion and the lateral confinment by the 2D particle flow code
(PFC2D). It is shown that the lateral confinement may change the path of crack
propagation in a specimen compared to that of the uniaxially-loaded one. Various
senarios of the mixed mode radial crack propagation around the holes are obtained,
and both the wing (induced tensile) cracks and secondary (shear) cracks are produced
and propagated in various paths due to a change in the confining pressure. The
fracturing pattern changes from a single tensile crack to that of the several shear bands
by increasing the confining pressure. Also the number of shear cracks is increased by
increasing the lateral confinement. On the other hand, as the confining pressure
increases, the wing cracks start their growth from the walls and reach the center of the
cracks under high confinements.
Keywords :
Experimental modeling , Crack propagation path , Confining stress , Pre-holed specimens , PFC2D
