C CDP       SOURCE    CHAT      05/01/12    21:51:34     5004           
      SUBROUTINE CDP(TENS,ADP,RDP,VDP)                                          
      IMPLICIT INTEGER(I-N)
      IMPLICIT REAL*8(A-H,O-Z)                                                  
      DIMENSION TENS(3)                                                         
C                                                                               
C----------------------------------------------------                           
C     CETTE ROUTINE PERMET DE CALCULER LA VALEUR    |                           
C     DU DRUCKER PRAGER                             |                           
C----------------------------------------------------                           
C                                                                               
      VDP=TENS(1)*TENS(1)+TENS(2)*TENS(2)-TENS(1)*TENS(2)                       
     1 +3.D0*TENS(3)*TENS(3)                                                    
      VDP=SQRT(VDP)+ADP*(TENS(1)+TENS(2))-RDP                                   
      RETURN                                                                    
      END