Hwy. 40:36 Backslope Mudslide at McIntyre Mine Access 2006-1002C GP #25 August 2006 Photo 1 Photo 2 Photo 4 Photo 3 Mud debris run-out onto highway Looking east (away from Grande Cache) Looking across at adjacent mountain slope - Mud slide debris run-off from top of backslope (left) - Folding of sedimentary rock strata - Access to McIntyre Mine (Junction with Hwy. 40) – right of photo – is opposite to - Exposure of rock strata to weathering and a source of slide flow debris run-out location of debris Looking south at bottom of Smoky River valley from high elevation (close to top of mountain) Close-up - Highway and Smoky River at toe of valley slope - Folding, tectonic stress on sedimentary rock and its fracturing - AIT geotechnical engineer climbed to top of valley - Weathering of rock of varying hardness and joint, layering to locate source of debris flow to take photos Photo taken on June/July 2006 Page 1 of 12
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Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 1 Photo 2
Photo 4Photo 3
Mud debris run-out
onto highway
Looking east (away from Grande Cache) Looking across at adjacent mountain slope
- Mud slide debris run-off from top of backslope (left) - Folding of sedimentary rock strata
- Access to McIntyre Mine (Junction with Hwy. 40) – right of photo – is opposite to - Exposure of rock strata to weathering and a source of slide flow debris
run-out location of debris
Looking south at bottom of Smoky River valley from high elevation (close to top of mountain) Close-up
- Highway and Smoky River at toe of valley slope - Folding, tectonic stress on sedimentary rock and its fracturing
- AIT geotechnical engineer climbed to top of valley - Weathering of rock of varying hardness and joint, layering
to locate source of debris flow to take photos
Photo taken on June/July 2006
Page 1 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 5 Photo 6
- High elevation area of valley slope - Steep slope and gravitational movement of debris rock and soil
- Fracturing and weathering of shale rock and soil as source of mudslide debris along debris run down valley
Photo 7
- Steep slope enhances gravity movement of fractured rock masses and soils
along the debris run down valley
Photo 8
Weathering of shale sedimentary rock at high elevation areas Varying size of weathered rock along debris run path
- Weathered rock can be of varying sizes into soil and rock
Photo taken on June/July 2006
Page 2 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 9 Photo 10
Looking downslope - Transport and gravity movement of varying sizes of rock
- Steep ravine path for gravity flow of debris down valley
Photo 11 Photo 12
- Steep gully run-out path for debris flow - Additional sources of fractured rock along the debris run out gully
path of debris
Photo taken on June/July 2006
Page 3 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 13 Photo 14
Steep gully as result of eroding forces of debris flow - Another view steep debris run-out path
- Into dipping layer of rock strata
Photo 15
- Into fault zones of previous tectonic movements
Photo 16
- Previous folding and faulting of rock strata provide a source of - Folding of rock layers
rock and soil material for debris flow - Steep gully requires a rope for up-climbing
Photo taken on June/July 2006
Page 4 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 17 Photo 18
- Steep dipping and varying layering and faulting of sedimentary rock - Steep ravine and substantial supply of debris from fracturing and
– previous tectonic activities weathering of folding of rock layers
Photo 19 Photo 20
- Another view of folding and stress fracturing of rock layers - Steep vertical dipping and bending of rock layer
– supply of rock debris along debris run path indicate substantial tectonic activities and faulting to result weak rock
to provide highly fractured rock source for debris flow
Photo taken on June/July 2006
Page 5 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 21 Photo 22
Daylighting of rock joint and layers of folded sedimentary rock A steep ravine gorge eroded into rock by debris flow bedload
- Folding and stress fracture and exposure of rock render easy erosion - A steep run-out path for debris flow down valley
and weathering
Photo 23
- Gravity movement of rock debris down steep rock face
Photo 24
- Close up of rock debris along run-out flow path - A steep ravine gorge carved by debris flow bedload
Photo taken on June/July 2006
Page 6 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 25 Photo 26
- Looking downslope - Steep dip of rock layer
- Undulation of debris flow path indicative of variation of rock - Large toppled rock pieces
hardness and layering - Steep gorge as result of downcutting erosion by debris bedload
flow along run-out path
Photo 27 Photo 28
- Downcutting of debris run-out path into rock - Another view
Photo taken on June/July 2006
Page 7 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 29 Photo 30
- Tree undermined and sheared off by debris flow along run-out path - Original valley surface prior to downcutting along run-out path
- Expose rooting after downcutting
Photo 31 Photo 32
- Part deposition and part downcutting of debris flow along run-out path - Slight tortuous path (at lower slope of gentler gradient) to allow
at lower portion of slope with gentler gradient deposition of debris flow bedload
Photo taken on June/July 2006
Page 8 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 33 Photo 34
Deposition of boulder size rocks - Another view
Photo 35
- Lower stretch of valley slope of gentler grade
Photo 36
- Debris formed by a mixture of boulder (fractured rock) - Steep creek bank height (about 2m)
and clay (decomposed shale) - Bank height partly contributed by deposition of over-spilled bedload
- Bank height partly (minor portion) contributed by downcutting
Photo taken on June/July 2006
Page 9 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 37 Photo 38
- Height of run-out path (about 2m) along lower part of slope - Gentle gradient area along terrace just above highway backslope
- Formed from a mosaic of mixed fractured rock and mud and clay
Photo 39
- A product of deposition of bedload along lower valley slope of
a gentle gradient (valley terrace above backslope)
Photo 40
- Another view of lower gradient flow path at terrace above - Partial view of a small clearing in attempt to construct a storage area
highway backslope to delay debris flow run-out onto highway; this area will be
reconstructed to re-direct flow to a natural ravine area
to the west
Photo taken on June/July 2006
Page 10 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 41 Photo 42
Debris run-out path Lower part of debris run-out path
- 2m bank height (man-height) - Gentle gradient for natural deposition
Photo 43
- Deposition debris material forming the bank material
Photo 44
A view of the partially completed debris storage area, further work is require to
- Re-route debris flow to a west outlet
- Increase size of storage
Photo taken on June/July 2006
Page 11 of 12
Hwy. 40:36
Backslope Mudslide at McIntyre Mine Access
2006-1002C GP #25 August 2006
Photo 45 Photo 46
Catch water ditch (along top edge of backslope) – looking downgrade towards highway and river Another view of catch water ditch
- Outfall of surface run-off to highway ditch - Looking upgrade along top edge of backslope
- Drains water along down top edge of backslope
Photo 47
- Debris run-out overshoot this ditch and over-spilled debris to highway
(to left of photo)
Photo 48
Another view of catch water ditch - Catch water ditch outfall onto highway ditch
- Looking downgrade towards highway - Debris run-out (from July 2006 event) still visible along ditch and
not fully removed
Photo taken on June/July 2006
Page 12 of 12
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