As an example, the resulting nondimensional tables may be used as follows; 

 Let: $ = 0° 



e 



= 20° 



7 



Li 



- 4 n ft 



w 





Z 



= 6.3 ft 



c 



= 320 lb/ft 2 



Y b 



= 41.60 lb/ft 3 



Y t 



= 80 lb/ft 3 



cc 



= 75° 



It is desired that the active stress for the above conditions be determined. The 

 nondimensional parameters Y and Y' are calculated as follows: 



Y,Z (80) (4.0) 

 Y = _Li^ = = L0 , 



c 320 



Y,(Z-Z ) (41.60) (6.3-4.0) 

 Y < = _2 SL_ = ~ 0.3. 



c 320 



The upper portion of table 4 is applicable for the example values of <)>, 6, Y, and Y'; 

 therefore, values are obtained for parameters N" and T" from the line corresponding to 

 the a value of 75° : 



N" = -0.4902, 

 c ' 



T" = 0.5846. 



c 



a 



Since N" = — , then cL = cN'J = (320) (-0.4902) = -157.0 lb/ft 2 , which is the active 



C C C V- j 



Q 



effective normal stress on a plane inclined at an angle « of 75°. Since T'^ = — , then 



= C T'^ = (320) (0.5846) = 186.8 lb/ft 2 , which is the tangential stress on a plane 

 inclined at an angle of 75°. 



27 



