A circular borehole with four fractures in its wall in an infinite rock mass is subjected to compressive stress of 50MPa and confining stress of 10MPa. The borehole is also subjected to an internal hydraulic pressure of 10MPa. The inclination of the fractures is -45°. The material properties of the rock mass and fractures are the same as in Examples 1 and 3.
The fractures are found to propagate toward each other in mode II and finally form borehole breakouts.
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TITLE
Fracture propagation to form borehole breakouts
SYMMETRY -- Model symmetry
4 0.00 0.00
MODULUS - Poisson's Ratio and Young's modulus
0.25 0.40E+11
TOUGHNESS -- Gic and Giic
50. 1000.
PROPERIES -- mat, kn. ks,phi,coh
1 0.10E+13 0.10E+13 30.0 0.00E+00
GWINDOW -- xmin,xmax,ymin,ymax
-2.00 2.00 -2.00 2.00
STRESSES -- sxx,syy,sxy
-10.0E+06 -50.00E+06 0.00E+00
FRACTURE -- nume,xbeg,ybeg,xend,yend,kode,mat
3 0.700 0.700 0.90 0.60 2 1
ARCH -- nume,xcen,ycen,diam,ang1,ang2,kode,ss,sn
15 0.0 0.0 2.0 0.0 90.0 1 0.00E+00 -10.E+06
CYCL 1000
ENDFILE
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