a me O N I T O R I N G P A R T C: S E P T E M B - PDF document

a me O N I T O R I N G P A R T C: S E P T E M B E R 2 0 0 3 M A N D S L I D E R I S K A S S E S S M E N T L G H L E V E L ) G I O N ( P E A C E R I V E R V A L L E Y / H I P E A C E R E SITE PH10: EUREKA RIVER (SOUTH OF WORSLEY) O C A T I O N : 8 6 - 8 - W 6 M L E G A L L g h w a y : S t a t i o n 1 0 + 6 0 0 L o c a t i o n a l o n g H i S H 7 2 6 : 0 2 AT F I L E : Station 1 0+600 r b e r i n s t a l l e d t w o s l o p e r E n g i n e e r i n g L t d . f o r t h e M D . T h u e s l i d e w a s i n v e s t i g a t e d b y T h u r b e T h of h e m o n i t o r i n g s c h e d u l e i n O c t o b e r n d E R 9 8 - 2 , w h i c h w e r e a d d e d t o t i n c l i n o m e t e r s , E R 9 8 - 1 a w e r e i n s t a l l e d in d a s E R 0 2 - 1 t h r o u g h E R - 0 2 - 3 e e s l o p e i n c l i n o m e t e r s d e s i g n a t e 2 0 0 0 . T h r S e p t e m b e r 2 0 0 2 . Observations h e t o e of t h e s l o p e . I t d i d n o t a t e d d o w n h i l l of t h e r o a d t o w a r d s t S l o p e i n c l i n o m e t e r E R 9 8 - 1 is l o c w a s a n s h o w e d p o t e n t i a l t i l t i n g , w h i c h t m o v e m e n t z o n e s . I t , h o w e v e r , r e c o r d a n y d i s t i n c p . S l o p e i n c l i n o m e t e r b e d e e p e r t h a n t h e i n s t r u m e n t t i a t i o n t h a t t h e m o v e m e n t z o n e m a y i n d i c p p e r 3 m . T h e d s u r f i c i a l m o v e m e n t s w i t h i n t h e u e d at t h e t o p of t h e s l o p e , r e c o r d e E R 9 8 - 2 , l o c a t p p r o x i m a t e l y 1 7 m m p e r y e a r . m o v e m e n t r a t e w a s a e d m o v e m e n t in a d i s t i n c t s h e a r o c a t e d d o w n h i l l of t h e r o a d , r e c o r d S l o p e i n c l i n o m e t e r E R 0 2 - 1 , l u b s t a n t i a l l y a p p r o x i m a t e l y 1 5 5 m m p e r y e a r ; s d e p t h . T h e m o v e m e n t r a t e w a s z o n e a t 1 6 m e r E R 0 2 - 2 l o c a t e d f u r t h e r e c o r d e d i n M a y 2 0 0 3 . I n c l i n o m e t i g h e r t h a n t h e 6 5 m m p e r y e a r r h T h e n c t s h e a r m o v e m e n t a t 9 m d e p t h . E u r e k a R i v e r a l s o r e c o r d e d d i s t i d o w n h i l l c l o s e r t o t h e p e r y e a r i n M a y . m p e r y e a r , c o m p a r e d t o 6 0 m m e n t r a t e h a d a c c e l e r a t e d t o 7 8 m m o v e m n d i c a t e d a r o a d t o t h e n o r t h of E R 0 2 - 2 . I t i R 0 2 - 3 i s l o c a t e d d o w n h i l l f r o m t h e I n c l i n o m e t e r E f r o m 7 m m m e n t r a t e w a s 3 m m p e r y e a r , d o w n m e n t z o n e at 9 m d e p t h . T h e m o v e d i s t i n c t m o v e per year in May. e r 2 0 0 2 t o m o n i t o r p o r e w a t e r s w e r e a l s o i n s t a l l e d i n S e p t e m b T h r e e p n e u m a t i c p i e z o m e t e r d e d p o r e p r e s s u r e s a r e d o n S e p t e m b e r 2 7 , a n d t h e r e c o r s s u r e s . T h e p i e z o m e t e r s w e r e r e a p r e e r n o s i g n i f i c a n t c h a n g e i n p o r e w a t o w i n g t a b l e . T h e d a t a i n d i c a t e s s u m m a r i z e d i n t h e f o l l s i n c e J u n e 2 0 0 3 . p r e s s u r e s Pore Water Pressure (kPa) Depth Plezom lnstrume eter No. nt 1 .0 . (m) Sept. 27, 2003 Sept. 24, 2002 June 2, 2003 52 2771 2 10 53 33 ER 02-1 31 28 2771 0 19 32 5 7 E R 02-2 2 7711 14.5 4 Page (1) tO Eureka Par1 C_S ept 2003 doc P. IP ROJECTS\6600\Eg08628\ Par1 C - Sept 200 3166 28 Site PH

me a The condition of the road section within the slide area has deteriorated significantly over the past few years. The road surface experienced extensive pavement cracks and settlement, and had to be patched three times since 2001 ; in September 2001 , in the summer of 2002, and in In September 2003, the newly patched road experienced further the summer of 2003. settlement in the vicinity of inclinometer ER-98-2, but no pavement cracks were observed. Downhill from the road, ground cracks became wider (up to 40 mm) and deeper (up to 500 mm). The slide scarp became more defined particularly in the vicinity of slope inclinometers ER02-2 and ER02-3. Interpretation The existing shallow slope inclinometers (ER98-1 and ER-98-2) did not show any distinct shear zones, even though the slide has been active for several years. Data from the deep slope inclinometers installed in 2002 (ER02-1, ER02-2, and ER02-3) confirmed that the slide is deep- seated. The data also suggests the slide is one large slide extending from the road to the Eureka River, rather than several shallow slumps. The monitoring data and field observations indicate that the slide is active with a steady or The recorded movement rates in September 2003 ranged increasing rate of movement. between 78 and 155 mm per year, which is considered to be a high rate of movement compared to other sites. Should the movement rates remain that high, the condition of the newly patched road is likely to deteriorate. It is also anticipated that slope inclinometers ER02-1 and ER02-2 would shear off in the near future. Since the boundaries of the slide extend across the road, any significant slide movement is likely to cause traffic disruption. It is recommended that remedial measures be designed and implement at this site. e ( 2 ) P a g P ·\ PROJECTS\8600 1Eg086 281Par1 C ·Se pt 2003\8628 Si te PH10 Eureka Par1 C_Sept 2003. d o c

Alberta Transportation - Instrumentation Monitoring Results FILE NAME: ER98 MAPID : PH10 PROJECT: Eu re ka (Stn. 10+600) Stickup Ground Azimuth Monitor ing Location of Rate(s) of General comments Instrument Reading I. D. Depth (m) Elevati on A+ Groove Date movement movement zone(s) (mm/year) (m) (m) fr . Mag.North (m) 0-2.5 Ap pe rantly some ti lting is occ urring, 14 Sept27 , 2003 no clear distinct movement zone ER98-1 14 Se p t27,2003 0-4 17 Surficial movement ER98-2 27.1 Sept27,2003 16 -17 155 Movement along a distinct shear zone ER 02-1 Movement rate accelerated substantially since Ma y 2003 21 .1 Sept 27, 2003 9 78 Movement along a distinct she ar zone, ER 02-2 movement ra te accelerated s in ce May 2003 Movement ra te deccelerated sin ce I 18.1 Sept27 , 2003 9 3 Minor m ov ement along a distinct shear zon1 ER 02-3 Ma y 2003