ABSTRACT
The p r e s e n c e o f g r o u n d w a t e r i n t h e r o c k mass s u r r o u n d i n g an
open p i t has a d e t r i m e n t a l e f f e c t upon t h e m i n i n g programme
f o r t h e f o l l o w i n g r e a s o n s :
a) Water pressure r e d u c e s t h e s t a b i l i t y o f t h e s l o p e s by
r e d u c i n g t h e s h e a r s t r e n g t h o f p o t e n t i a l f a i l u r e
s u r f a c e s as d e s c r i b e d on pages 2k and 25-W a t e r p r e s s u r e i n t e n s i o n c r a c k s o r s i m i l a r n e a r v e r t i c a l
f i s s u r e s r e d u c e s s t a b i l i t y by i n c r e a s i n g t h e f o r c e s
t e n d i n g t o i n d u c e s l i d i n g ( p a g e 2 6 ) .
