Engineering Rock Mechanics

Questions 7 7.7- 7 7.7 0: testing techniques 443

touring corresponding to the fracture frequency values in the different
directions.
Direction of
maximal

• Pole, i.e. set normal

Extreme values

0 Local minimum

0 Global minimum.3.36

0 Local maximum

Global maximum 8.86

Contour values

8.00

7.00

6.00

5.00

4.00

~ ~ ~ ~ ~ ~ ~ ~

~~~~~~~~

• 
  
  
  
  • 
    
    
    
    • 
      
      
      
      • 
        
        
        
        • 
          
          
          
          • 
            
            
            
            • 
              
              
              
              • -.
              
              
              
              
            
            
            
            
          
          
          
          
        
        
        
        
      
      
      
      
    
    
    
    
  
  
  
  


• 
  

+ with set number

Explain from first principles why the directions of the minimal and
maximal frequencies occur where they do.

Q11.5 When cyclic deformability tests are conducted on rock masses,
the typical force-displacement curve is as shown below (Schneider, 1967;
Goodman, 1989).

/

1 /I

-/ //

Local unloading modulus

Local reloading modulus

!!

0

LL

Explain why, with cycles of repeated unloading and reloading, the
curve manifests different unloading and reloading moduli, permanent
deformations and hysteresis.