december 19, 2011 cg25352.300 mr. ross dickson alberta ... landslide… · amec envi ronment &...

AMEC Environment & Infrastructure A division of AMEC Americas Limited 140 Quarry Park Blvd. SE Calgary, AB, CANADA T2C 3G3 Tel +1 (403) 248-4331 Fax +1 (403) 248-2188 www.amec.com

R:\Projects\Calgary Geo\CG25XXX - AT Projects\CE061_2008\CG25352 - AT Southern Region 2011\300 - Monitoring\SI Data + reports\S38 - Callum Creek\Fall 2011

Report\Fall 2011 AT Monitoring - S38,FINAL,tc,bb,ab.doc

December 19, 2011

CG25352.300

Mr. Ross Dickson

Alberta Transportation

2nd Floor, 803 Manning Road NE

Calgary, AB T2E 7M8

Dear Ross:

Re: Southern Region Geohazard Assessment

Fall 2011 Instrumentation Monitoring Results

Site S38: Highway 22:08, Callum Creek Landslide Site

This letter documents the Fall 2011 instrument readings at the above-noted site and presents

an updated site plan sketch, instrument data, and plots.

1.0 OBSERVATIONS

1.1 Field Program and Instrumentation Status

One slope inclinometer (SI) and two vibrating wire piezometers were read at the S38 –

Highway 22:08 site on November 1, 2011 by Mr. Tyler Clay, EIT of AMEC Environment &

Infrastructure (AMEC), a division of AMEC Americas Limited.

The SI’s were read using a metric Slope Indicator probe and Digitilt Datamate readout

manufactured by Durham Geo Slope Indicator (DGSI). Inclinometer reading depths were

referenced to the top of the SI casing. The vibrating wire piezometer was read using a VW data

recorder also manufactured by DGSI.

Please refer to the attached Figure S38-1 for a site plan showing the instrument locations.

The geotechnical investigation and instrument installations were recommended by AMEC after

a site inspection was performed on March 3, 2011 at Alberta Transportation’s (AT) request. At

the time of the site inspection, the road surface was exhibiting arc shaped cracking and

settlement across an approximately 80 to 100 m long segment of the road, indicating a potential

landslide headscarp. The road at the site has two lanes and appears to be a cut/fill embankment

along the natural valley slope. The slope below the road is at an angle of 17 to 18°. Settlement

of the road surface downslope of the cracking was in the order of 50 to 100 mm, with visible

deflection of the guardrail. The northern end of the affected road segment had a series of

Alberta Transportation Fall 2011 Instrumentation Monitoring Results Southern Region Site S38 – Highway 22:08, Callum Creek Landslide Site December 19, 2011



tension cracks in the pavement, roughly parallel to the road direction, and possibly indicating

future expansion of the arc-shaped cracking.

The geotechnical investigation and instrument installations were recommended to investigate

the subsurface and ground movement conditions, provide information to be used in potential

future repair work, and establish ongoing monitoring of slope movement and groundwater

pressure at the site. Please refer to the 2011 Geotechnical Investigation, Instrument

Installations and Initial Readings report for further background information1.

2.0 INTERPRETATION

2.1 General

Plots of the instrument data are presented in the attached figures, and summarized in the following sections.

2.2 Zones of Movement

The previously identified movement zone in SI 11-01 at 11 m depth shows continued

displacement. No new movement zones have been identified.

2.3 Interpretation of Monitoring Results and Recommendations

2.3.1 Interpretation

SI 11-01 (Figures S38-2 and S38-4)

• The November 2011 readings show continued displacement at and above the movement zone at 11 m depth identified from the July 2011 readings. The total displacement at this zone is now approximately 42 mm since May 2011, an increase of 11 mm since the July 2011 readings. The rate of movement since July 2011 is lower than was measured between May and July 2011.

SI 11-02 (Figures S38-5 and S38-6)

• This SI was found obstructed at 9.4 m depth during the July 2011 readings, likely due to landslide movement causing excessive deformation of the SI casing. The May 2011 readings had indicated that movement was occurring above 9.4 m depth over a broad movement zone.

Vibrating Wire Piezometers VW# 10-6697 and VW# 10-6710 (Figure S38-7 and Table S38-2)

• VW# 10-6697 – This piezometer tip is installed approximately 14 m below the ground surface. To date it has only measured relatively small pressures and it is possible that the piezometer tip is above the groundwater level and not fully saturated.

1 AMEC Report, “S38 – Hwy 22:08 – Callum Creek Landslide Site 2011 Geotechnical Investigation,

Instrument Installations and Initial Readings”, submitted to Alberta Transportation, June 2011, AMEC File

No CG25359.




• VW# 10-6710 – This piezometer tip is installed approximately 6.5 m below the ground

surface. The current piezometric elevation measured at this tip is approximately 2.2 m

below the ground surface or an equivalent pressure of 41.7 kPa. This is comparable to

the previous reading in July 2011. Since this piezometer tip is fully saturated and is

installed at a higher elevation than the 10-6697 tip, it may be indicative of a perched

water table in this area. These water pressures could be contributing to the active

movement observed at this site.

3.0 RECOMMENDATIONS AND PATH FORWARD

AMEC will be designing repair measures for this site during the winter of 2011/2012, and it is

understood that AT is planning on constructing a repair in Summer 2012.

As part of the upcoming repair design, AMEC will assess the need for additional readings of the

functioning SI and the piezometers, and will provide recommendations for additional instrument

installations and post-repair monitoring in the report on the repair design.

The annual site inspections by AT and AMEC personnel should be continued in 2012.

4.0 INSTRUMENTATION REPAIRS AND MAINTENANCE REQUIRED

No repairs are required at this time. Recommendations for the replacement of SI 11-02 (and

SI 11-01 if it goes out of service), if warranted for post-repair monitoring, will be provided in the

upcoming repair design report.


R:\Projects\Calgary Geo\CG25XXX - AT Projects\CE061_2008\CG25352 - AT Southern Region 2011\300 - Monitoring\SI Data + reports\S38 - Callum Creek\Fall 2011 Report\Fall 2011 AT Monitoring - S38,FINAL,tc,bb,ab.doc

TABLE S38-1

FALL 2011 – Callum Creek Landslide

Slope Inclinometer Instrumentation

Reading Summary

Date Monitored: November 1, 2011

INSTRUMENT

NAME

DATE

INITIALIZED

TOTAL

CUMULATIVE

RESULTANT

MOVEMENT AT

DEPTH SINCE

INITIAL

READING

MAXIMUM

RATE OF

MOVEMENT

CURRENT

STATUS

DATE OF

PREVIOUS

READING

SINCE PREVIOUS READING

INCREMENTAL

MOVEMENT

RATE OF

MOVEMENT

CHANGE IN

RATE OF

MOVEMENT

SI 11-01

April 12, 2011

42.2 mm at 11 m

depth

159 mm/yr

(July 2011)

Operational July 2011 11.2 mm 37 mm/yr -122 mm/yr

SI 11-02

April 12, 2011

Sheared at

9.40 m BGS

(July 2011)

n/a Out of operation July 2011 n/a n/a n/a


R:\Projects\Calgary Geo\CG25XXX - AT Projects\CE061_2008\CG25352 - AT Southern Region 2011\300 - Monitoring\SI Data + reports\S38 - Callum Creek\Fall 2011 Report\Fall 2011 AT Monitoring - S38,FINAL,tc,bb,ab.doc

TABLE S38-2

Fall 2011 – Callum Creek Landslide

Piezometer Instrumentation, Reading Summary

Date Monitored: November 1, 2011

INSTRUMENT

TIP SERIAL

NUMBER

DATE

INITIALIZED

TIP DEPTH

BGS

(m)

GROUND

ELEVATION

(m)

CURRENT

STATUS

MINIUMUM

EQUIVALENT

PIEZOMETRIC

DEPTH BGS

(m)

CURRENT

EQUIVALENT

PIEZOMETRIC

DEPTH BGS

(m)

PREVIOUS

EQUIVALENT

PIEZOMETRIC

DEPTH BGS

(m)

CHANGE IN

CALCULATED

EQUIVALENT

PIEZOMETRIC

DEPTH SINCE

PREVIOUS READING

(m)

PORE WATER

PRESSURE

RATIO

(ru)

VW #10-6697 April 12, 2011 14

1340* Operational

13.35

(November

2011)

13.35

13.53 + 0.18 0.02

VW #10-6710 April 12, 2011 6.5

1340* Operational 1.91

(July 2011)

2.21

1.91 - 0.30 0.36

*approximate GPS point ± 3 m




5.0 CLOSURE

This report has been prepared for the exclusive use of Alberta Transportation for the specific

project described herein. Any use which a third party makes of this report, or any reliance on or

decisions to be made based on it are the responsibility of such third parties. AMEC Environment

& Infrastructure, a division of AMEC Americas Limited, cannot accept responsibility for such

damages, if any, suffered by any third party as a result of decisions made or actions based on

this report. This report has been prepared in accordance with accepted geotechnical

engineering practices. No other warranty, expressed or implied, is made.

We trust that this meets your needs at this time. Please contact the undersigned if you have any

questions or require any further information.

Respectfully Submitted,

AMEC Environment & Infrastructure,

a division of AMEC Americas Limited

[ORIGINAL SIGNED AND STAMPED ON DECEMEBER 19, 2011]

Tyler Clay, B.A.Sc., EIT Bryan Bale, M.Sc., P.Eng.

Geological Engineer Geotechnical Engineer

Reviewed by: APEGGA Permit to Practice No. P-04546

Andrew Bidwell, M.Eng., P.Eng.

Associate Geological Engineer



SECTION D

Southern Region Geohazard Assignment

Site S38 – Callum Creek Landslide

Fall 2011 Instrument Data and Plots

BH#11-01

HWY 22

N

Project Revision

Hwy 22:08 - Callum Creek Site

Alberta TransportationClient

Figure S38-1

Date:

Dec-11

LEGEND

Area of cracking /

settlement

Slope Inclinometers

VW Piezometers

BH #11-02

BH #11-03

• VW #10-6679

• VW #10-6710

0 m 100 m

Job No.

File No.:

CG25352.300

Hwy 22:08 - Callum Creek Site

Site Plan and Location

Dec-11

SCALE AND INSTRUMENT LOCATIONS ARE APPROXIMATE

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-100 -50 0 50 100

18

16

14

12

10

8

6

4

2

0

-100 -50 0 50 100

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-50 -25 0 25 50

18

16

14

12

10

8

6

4

2

0

-50 -25 0 25 50

LEGEND

Initial 12 Apr2011

12 Apr2011

2 May2011

14 Jul2011

1 Nov2011

Figure S38-2

Towards 060° (Downslope) Towards 060° (Downslope)

Cumulative Deflection

Direction A

Deflection (mm)

Incremental Deflection

Direction A

Deflection (mm)

Ref. Elevation 1340 m

R:\Projects\Calgary Geo\CG25XXX - AT Projects\CE061_2008\CG25352 - AT Southern Region 2011\300 - Monitoring\SI Data + reports\S38 - Callum Creek\Fall 2011 Data\CallumCK_11-01.gtl

S38 - Callum Creek, Inclinometer SI 11-01


AMEC Environment & Infrastructure - Calgary, AB

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-100 -50 0 50 100

18

16

14

12

10

8

6

4

2

0

-100 -50 0 50 100

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-50 -25 0 25 50

18

16

14

12

10

8

6

4

2

0

-50 -25 0 25 50

LEGEND

Initial 12 Apr2011

12 Apr2011

2 May2011

14 Jul2011

1 Nov2011

Figure S38-3

Towards 150° Towards 150°


Direction B

Deflection (mm)


Direction B

Deflection (mm)



S38 - Callum Creek, Inclinometer SI 11-01



15

20

25

30

35

40

45

50

Dis

pla

cem

en

t (m

m)

November 2011 -

42 mm displacment at

43 degrees bearing

Client

Project Revision

movement_fall2011.xlsx

Alberta Transportation Figure S38-4

S38 - Hwy 22:08, Callum Creek SiteDate:

Dec-11

SI 11-01

Resultant Displacement at 11 m Depth

Job No.

CG25352.300File No.:

0

5

10

15

26-Feb-11 17-Apr-11 6-Jun-11 26-Jul-11 14-Sep-11 3-Nov-11 23-Dec-11

20

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-50 -25 0 25 50

20

18

16

14

12

10

8

6

4

2

0

-50 -25 0 25 50

20

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-10 -5 0 5 10

20

18

16

14

12

10

8

6

4

2

0

-10 -5 0 5 10

LEGEND

Initial 12 Apr2011

12 Apr2011

2 May2011

Figure S38-5

Towards 100° (Downslope)

July 14, 2011 - SI Pinched at

9.40 m below ground surface.

Towards 100° (Downslope)




Direction A

Deflection (mm)


Direction A

Deflection (mm)



Callum Creek, Inclinometer 11-02



20

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-50 -25 0 25 50

20

18

16

14

12

10

8

6

4

2

0

-50 -25 0 25 50

20

18

16

14

12

10

8

6

4

2

0

Depth

(m)

-10 -5 0 5 10

20

18

16

14

12

10

8

6

4

2

0

-10 -5 0 5 10

LEGEND

Initial 12 Apr2011

12 Apr2011

2 May2011

Figure S38-6

Towards 190°



Towards 190°




Direction B

Deflection (mm)


Direction B

Deflection (mm)



Callum Creek, Inclinometer 11-02



1326

1328

1330

1332

1334

1336

1338

1340

1342

Eq

uiv

ale

nt

Pie

zo

me

tric

Ele

va

tio

n (

m)

Client

Project Revision

File No.:

Callum_Piezos.xlsx

Alberta Transportation Figure S38-7

Hwy 22:08 - Callum Creek SiteDate:

Dec-11

BH# 11-03 - Equivalent Piezometric Elevations

Job No.

CG25352.300

1322

1324

Eq

uiv

ale

nt

Pie

zo

me

tric

Ele

va

tio

n (

m)

VW#10-6710 VW# 10-6710 Tip Elev VW#10-6697

VW# 10-6697 Tip Elev Ground Elev

Note:Elevations relative to assumed ground level of 1340 m.

december 19, 2011 cg25352.300 mr. ross dickson alberta ... landslide… · amec envi ronment &...

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