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Stabilizing Slides

Using a Spider Excavator

Eric L Kay

Rob Wilson

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Part 1 - Spider Excavator, (the tool)

Part 2 – Stabilizing Landslide Headscarps

Part 3 - Multiflow Drainpipe

Part 4 - Contour Drainage

Eric

Eric

Rob

Rob

Stabilizing Slides

3.. . Part 1 - Spider Excavator Description

Kaiser X5 M

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Work on steep slopes 100% (One to One slope)

Walks on 4 legs

Extending stick

Twist wrist bucket

Hydraulic thumb

Hydraulic winch 12,000lbs

Pushes and pulls itself around

Optional Hydrostatic drive (6kmph) Kaiser X5 M

Rolls on two back wheels

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Agility

Step over;

- Logs

- Shrubs

- Small trees

- Boulders

Schaeff HS 40 D

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Safely work on a 1 to 1 slopeaiser X5 M

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Previously deactivated road system

site accessibility

Schaeff 41 M

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Beyond the reach of a normal excavator

Perched material in the gully

Schaeff 41 M

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The power of an excavator1 1/2 times the size

Schaeff HS 40 D

10Working in water 2 meters deep

Schaeff HS 40 D

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Transportable by HelicopterFor remote site work

Fueled and ready to work

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Part 2 – Stabilizing

Landslide Headscarps

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Retrogressive Failures – Issues:• Maintenance costs/problems – Loss of road use, temporary/permanent

• Impediment to re-establishment of vegetation

• Destruction of remedial works

• Loss of productive land inventory

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Unstable headscarp

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Kaiser X5 M

Sloping back of the headscarp

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Large woody debrisKaiser X5 M

Sloping back of the headscarp

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Caution

� � � � �

Need good

understanding

of soils, water

and slope processes

18Part 3 - Multiflow Drainpipe

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Multiflow pipeAvailable in 15,30 & 46 cm widths

Made up of multiple

miniature “Big O” pipes

laid flat, joined together

and covered in a filter

fabric

A viable alternative for

Drain rock

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Part 4 - Contour Drainage

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This site is located in the Cariboo Mountains where a “hanging glacial” valley slopes into a typical “U shaped glacial valley”.

Glacial fluvial out-wash deposits are buried below glacial till, resulting in seepage related slope instability problems.

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Road cut-slope. Tension crack showing evidence of slope

ilure, along with visible evidence of retrogression of the headscarp.

This site has been a an ongoing maintenance problem, with some

restriction of road use.

Tension crack – indicator

of slope failure

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The Spider Excavator digs a trench above the crest of the headscarp and behind the tension crack.

The trench is 3m in depth with the objective to interrupt the sub-surface water flows.

he base of the trench should lope at least 2% towards an utlet end of the drainage.

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he multiflow drainage composite was put

to the bottom of the trench, against the uphill

ope, and a 6 mil polyethylene sheet placed

ainst the down slope side for an impervious

arrier.

l placement was done from the surface. Workers

re not permitted to enter the trench.

e Multiflow pipe was attached to the poly and

wered into the trench from the surface.

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The multiflow drainage composite was put

into the bottom of the

trench, against the uphill slope, and a 6

mil polyethylene sheet against the down

slope side.

Excavator starts backfilling the

trench. Woody

debris is then scattered over top

Alternatively a composite

“Blanket Drain”

material such as Nudrain DM50 could

be employed

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Excavator starts backfilling the

trench. Woody

debris is then scattered over top

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Steady

seepage from

subsurface

drainage

collector

(Multiflow)

5 liters/min

X

60 min/hr

X

24 hrs day

= 7200 liters/day

That’s over 7000 kg less weight

within the slope on a day to day

basis!

What

difference

does a month

or two make?

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inished swale above head scarp with debris scattered over top.

wale directs surface water away from problem area.(Picture has been stretched to emphasize the swale)

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Finished drainage swale directing surface run-off to the flank of slide area

30table cut slope with reduced seepage after finishing the contour drainage worNo longer a continuous road maintenance issue not is there the problem of loss of road use.

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Thank You

Eric Kay - Rob Wilson

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ReferencesKaiser X5 M - JOHOE IncJoe Gisler 250 398-3507

Schaeff HS 40 D - Nu Creek DevelopmentsLen Masson 250 833-0173

Schaeff HS 41 M - J W Berry Trucking

Brad Berry 250 724-4912

Rob Wilson - Weldwood - 250 392-7731

Eric L Kay - Kay & Associates - 250 337-5096