Montana Department of Transportation PO Box 201001 Helena, … · 2020-05-05 · slide, geometry of the area outside the toe of the slide, and the gradient of the drainage ditch along

Montana Department of Transportation PO Box 201001

Helena, MT 59620-1001

Memorandum

To: Mike Taylor, P.E.

Engineering Services Supervisor – Billings District

From: Cameron Kloberdanz, P.E. (original report signed)

Geotechnical Manager – Billings District

Date: March 25, 2020

Subject: Preliminary Geotechnical Evaluation (460)

MT 80 - Geotechnical Study

STPX 80-2(4)49

UPN 9286000

The Geotechnical Section has conducted its Preliminary Geotechnical Evaluation of the subject

project. The following report is a summary of information gathered from a site visit, office review of

published and historical project information, preliminary subsurface investigation, and preliminary

analysis. The preliminary subsurface investigation was performed to assist in developing the scope

of any future work in the project area.

This report will complete geotechnical study phase of this project.

CMK:cmk

S:\GEOTECH\00_ACTIVE\9286000\9286000_Memo\9286000GTGDM460.DOCX

Attachments: Site Location Map

Slide and Boring Location Maps

Log of Borings

Slope Inclinometer Plots

ecopies: Rod Nelson, P.E., District Administrator

Dave Hedstrom, P.E., Hydraulics Engineer

Tom Martin, P.E., Environmental Bureau Chief

Geotechnical File

PRELIMINARY GEOTECHNICAL EVALUATION

MT 80 – GEOTECHNICAL STUDY PAGE 2 OF 10

UPN 9286000

1.0 Project Location and Description The project is located on State Route 80 in Fergus County, approximately 19 miles north of the City

of Stanford and 8 miles northwest of the Town of Coffee Creek. The study area begins at RP 48.5

and originally was to extend to RP 49.6. However due to an additional slide that occurred during this

study, the project was extended to the north. The proposed project was nominated as a geotechnical

study project to evaluate landslides along the roadway and assist with determining the scoping of any

additional remediation required.

2.0 Geology Soils in the project area consist of clay to boulder size particles from landslide deposits and alluvial

deposits along drainages. Bedrock formation material within the project area is mapped as Kevin

Member of the Marias River Shale Formation. Kevin Member consists of dark grey shale with

abundant limestone concretions with the lower part of the member containing many thin bentonite

beds.

3.0 Site Investigation The site investigation for the roadway project included a review of published data, site

reconnaissance, field investigation, and laboratory testing. In addition, all of the slide areas are within

the limits of the recently constructed Arrow Creek project and relevant project information was

reviewed. The information gathered during the investigation was used for a preliminary geotechnical

analysis to help determine the direction of this project.

3.1 Site Visit Cameron Kloberdanz of the Geotechnical and Pavement Bureau reviewed the project site multiple

times. Existing site conditions were observed and documented. Site conditions are described by slide

area with a station from the Arrow Creek project provided:

Southern Slide – STA 256

The first slide to the south is a failure in the roadway embankment. Throughout the duration of the

study the head scarp of the slide has been just outside the south travel lane in the roadway shoulder

(Photo 1). The slope was flattened to 2.5H:1V slope as part of the latest construction project. The

upper limits of the slide appear to be at the same location as the slide activity before the latest project.

Initially the failure was just to the north of a newly installed culvert, but eventually the slide limits

expanded across the culvert (Photo 2). Temporary measures were installed to keep the culvert from

separating further and keeping surface water flowing though the culvert. In addition, Maintenance

personnel frequently rebuild the shoulder to lessen the danger to the travelling public. The slide

movement is mostly perpendicular to the roadway. Currently the slide is about 120 feet long along

the head scarp on the shoulder of the roadway. The slide widens out to about 180 feet along the toe

of the slide; however, this is a rough estimate as the limits of the movement at the toe are less

pronounced on the surface.



UPN 9286000

Photo 1 – Head scarp in shoulder of roadway.

Photo 2 – Slide in roadway embankment with culvert.



UPN 9286000

Middle Slide Area – STA 271

The middle slide is also a failure in the roadway embankment. Originally the head scarp of the slide

extended across the south travel lane to about the center line of the roadway (Photo 3). During the

study a second lobe on the north edge of the slide activated with a head scarp crossing almost all the

way across the roadway (Photo 4). The slope was in the transition from a flattened to 2.5H:1V slope

to a dressed up 2H:1V slope as part of the latest construction project (Photo 5). In addition, the most

recent project rebuilt the drainage channel at the bottom of the slope and constructed a rip-rapped

lined ditch on the east side of the roadway where only a slight ditch had been before. Maintenance

personnel frequently patch the roadway and rebuild the shoulder to lessen the danger to the travelling

public. The slide movement is mostly perpendicular to the roadway. Currently the slide is about 190

feet long along the head scarp on the roadway. The slide widens out to about 250 feet along the toe

of the slide; however, this is a rough estimate as the limits of the movement at the toe are less

pronounced on the surface. In addition, there is a shallow failure along the same fill slope at about

STA 268 that is working its way up to the shoulder of the roadway.

Photo 3 – Middle slide head scarp extending to roadway CL.



UPN 9286000

Photo 4 – Middle Slide head scarp after extending across roadway.

Photo 5 – Middle Slide area before patching of the roadway.



UPN 9286000

North Slide Area – STA 309

During the geotechnical study of the other two slides, movement appeared in the roadway to the north

and was included in the study. The north slide is also a failure in the roadway embankment. The

head scarp of the slide extended across the south travel lane to about the center of the south bound

lane of the roadway and has remained in the same location (Photo 6). The slope was just outside two

slide areas which were stabilized with ground anchors and concrete facing blocks, but the slope was

not changed as part of the latest construction project (Photo 7). The most recent project realigned the

roadway and constructed a rip-rapped lined ditch on the east side of the roadway as well as rebuilt the

drainage channel at the bottom of the slope. Maintenance personnel frequently patch the roadway

and rebuild the shoulder to lessen the danger to the travelling public. Unlike the other slides, the slide

movement is at an angle of about twenty degrees from perpendicular. Currently the slide is about

100 feet long along the head scarp on the roadway. The slide widens out below the roadway, however

the toe of the slide is not very well defined on the surface. In addition, there is a gi-mongo slide

outside of MDT’s right-of-way that is failing into the toe of this slide and resulting in the blocking of

the drainage between the two slides.

Photo 6 – North slide head scarp extending into roadway.



UPN 9286000

Photo 7 – North slide slope with gi-mongo slide debris in foreground.

3.2 Project Review The Arrow Cr Slide Repair/MT11-1, UPN 7727000 project included these areas and was constructed

a few years ago. The focus of the project was mitigating two large slides which had been impacting

the roadway for decades, as well as mitigate some smaller slides along the roadway alignment.

During construction, some existing slides expanded, as well as some new slides developed, requiring

additional mitigation and change orders. This project was reviewed and provided preliminary

information on the ground survey for both the pre-project condition and the as-built condition. In

addition, the geotechnical reports from the project were reviewed to provide information from close

subsurface borings as well as soil properties used in the analysis.

3.3 Field Investigation The Field Investigation Unit advanced 7 borings along the project using a CME 1050 all-terrain drill

rig from December 20th, 2016 to January 25th, 2017, and July 11th, 2017 to July 18th, 2017, as part of

a preliminary subsurface investigation. The locations of the borings are noted in the boring logs and

a Boring Location Map is attached. Stationing and offsets use the alignment from the referenced

Arrow Cr Slide Repair/MT11-1 project.

Four of the borings were used to install slope inclinometers for monitoring the locations for

movement. One boring, 9286-6 was used to install a groundwater monitoring well. One additional

boring was drilled next to B-9286-5 and was used to install a groundwater monitoring well, but no

additional log was created. Borings were drilled to depths of 46.5 to 60.8 feet using Hollow-stem

augers. Standard Penetration Tests (SPT) were conducted at regular intervals and samples were



UPN 9286000

collected for laboratory analysis. The SPT soil samples collected during the investigation were tested

at the Geotechnical Section Laboratory.

3.4 Subsurface Soils and Conditions

The following discussion provides a summarized overview of the subsurface characteristics found

during the limited preliminary subsurface investigation and is provided for general project

discussions. However, not every condition encountered is provided, and the Boring Logs attached to

this report must be consulted for any design level details required.

Southern Slide – STA 256

Findings from the soil boring 9286000-3 shows an asphalt thickness of 0.6 feet over 1.1 feet of base

course. The base course consisted of poorly graded gravel with silt and sand. Below the base course,

the soils encountered were fill material that consisted of sandy lean clay and classified as A-6. Native

soils were encountered below the fill and consisted of expansive clay. Formation material was

encountered below the clay and consisted claystone and shale extending to 50.8 feet below the surface

where the boring terminated.

At the time of drilling, groundwater levels were not encountered within the depths explored.

Groundwater levels can fluctuate seasonally. Given the slide movement and the culvert close by, the

only general assumption that can be made is groundwater will most likely be encountered within the

slide mass at times during wetter seasons.


Findings from the soil borings 9286000-1 and 9286000-2, which were drilled in the shoulders of the

roadway, shows base course thickness ranging from 0.5 feet to 1.5 feet. The base course consisted

mostly of clayey or poorly graded gravel with sand and sometimes silt. Below the base course the

soils encountered consisted of fill material over native soils. Fill material ranged in thickness from

2.2 feet to 6.6 feet and consisted of sandy lean clay which classified as A-4 and A-6. Native soils

varied between the two borings but were mostly clay with varying amounts of sand classifying as A-

6 or A-7 soils or sand with varying amounts of clay classifying as A-2 or A-4 soils. Formation

material was encountered in both borings and consisted of claystone and shale at depths of 14.5 feet

to 27 feet below the surface.

At the time of drilling, groundwater levels were observed to be not encountered within the depths

explored in one boring and 27.9 feet below the ground surface in the other. Groundwater levels can

fluctuate seasonally and will most likely be encountered within the slide mass at times during wetter

seasons.


Findings from the soil borings 9286000-4 and 9286000-6, which were drilled in the shoulder of the

south bound lane at the top of the slide, and not that far apart, vary greatly. Base course was in only

one boring with a thickness of 0.8 feet. The base course consisted of poorly graded gravel with sand.

Fill material varied between the two borings and ranged in thickness from 8.2 feet to 27.6 feet and

consisted of either sand or gravel with varying amounts of silt which classified as A-1 and A-4, over

lean clay with varying amounts of sand which classified as A-7. Native soils were encountered in



UPN 9286000

only one boring and were elastic silt with sand classifying as A-7. Formation material was

encountered in both borings and consisted of claystone and shale at depths of 15.6 feet to 27.6 feet

below the surface.

Findings from the soil boring 9286000-5, which was drilled in the toe of the slide, shows native soils

over formation material. Native soils consisted of lean clay with varying amounts of sand and

classified as A-6 and A-7, and clayey sand with gravel classified as A-2. Formation material consisted

of claystone extending to 46.5 feet below the surface where the boring terminated.

At the time of drilling, groundwater levels were observed to be not encountered within the depths

explored in borings in the upper slide and 5.9 feet below the ground surface in the boring in the lower

slide. Groundwater levels can fluctuate seasonally and will most likely be encountered within the

slide mass most of the year at this location. In addition, groundwater monitoring wells were installed

at this slide and the information gathered can be reviewed as part of the design phase of the project.

4.0 Geotechnical Comments At this time, it is too early in the project to provide design level recommendations. However, to aid

the scoping of the design phase of the project, a general discussion is provided for each site and the

overall project direction.

4.1 Slide Mitigations Southern Slide – STA 256

The slide at station 256 is a small slide in the roadway embankment. Due to the fact the head scarp

of the slide has not advanced further into the roadway over all these years, indicates the failure surface

is most likely controlled by the depth and angle of the formation material in the area. The size of the

slide, geometry of the area outside the toe of the slide, and the gradient of the drainage ditch along

the slide all lend itself to stabilizing this slide with an earthen toe berm. The preliminary analysis

performed for this slide confirm a reasonable toe berm will be able to mitigate the slide movement.

Additionally, lightweight fill could potentially be used in combination with toe berm construction as

a possible mitigation alternative. The culvert on the edge of the slide will require reconstruction and

will be included with any site mitigation.

During the design phase additional subsurface information should be planned at the toe of the slide

to confirm the assumptions made on the subsurface conditions. In addition, depending on the

mitigation options selected for the other slides, a cost analysis should be used to verify the toe berm

method is still the most cost-effective mitigation option.


The slide at station 271 is a mid-sized slide in the roadway embankment. Due to the movement of the

head scarp both to the north and further into the roadway, as well as the visible shallow failure south

of the slide, the failure surface is most likely in a weak layer that extends beyond the limits of the

current slide. The preliminary analysis indicates the most cost-effective mitigation for the slide may

be a combination of a soil nail wall along the roadway at the top of the slide and slope flattening



UPN 9286000

below the wall. This option would also lend itself to extending the slope flattening outside the current

slide limits in both directions to improve the stability of the roadway embankment in this area.

During the design phase additional subsurface information should be planned at the toe of the slide

to confirm the assumptions made on the subsurface conditions. In addition, subsurface information

should also be gathered, and additional analysis performed to verify a new slide will not occur just

outside the performed mitigation.


The slide at station 309 is a large and complex failure along the roadway embankment. The variability

between the borings in the upper slide indicate the slide is occurring in a transition between fill slopes

and native slopes. The slide mitigation will be complicated by the large slides in the vicinity, two

stabilized previously with soil anchors and one active slide outside of MDT right-of-way. The

preliminary analysis indicates a deep failure surface. The slide mitigation will most likely require

multiple or tiered levels including structural components like either soil anchors or micro-piles.

During the design phase additional subsurface information should be planned along the limits of the

slide to better identify the mitigation limits and the required soil/formation material properties. In

addition, additional analysis will need to be performed to verify any new mitigation features will not

adversely affect the previously mitigated slides.

4.2 Project Development We believe the project will be best served moving forward with a traditional Design-Bid-Build

project. The proposed mitigations used at each site appear to be varied enough, and specialized

enough, to make it difficult for bidding/evaluating and administrating on a Design-Build project.

4.3 Cost Estimate A preliminary Engineers Cost Estimate has been developed for scoping purposes.

TOTAL costs

Estimated cost Inflation (INF)

(from PPMS)

w/INF + IDC

(from PPMS)

Slide STA 256 $900,000

Slide STA 271 $1,400,000

Slide STA 309 $1,900,000

Traffic Control $200,000

Subtotal $4,400,000

Mobilization (15%) $660,000

Subtotal $5,060,000

Contingencies (15%) $759,000

Total CN $5,819,000 $X $ X

CE (10%) $581,900 $X $ X

TOTAL CN+CE $6,400,900 $ X $ X

Please contact Cameron Kloberdanz at 444-9210 ([email protected]) or Dan Kluth at 444-6275

([email protected]) with any geotechnical questions concerning this project.

mailto:[email protected]

mailto:[email protected]

U.S. Department of Agriculture Farm Services Agency Aerial Photography Field Office.

±

0 0.015 0.03 0.045 0.060.0075Miles

MT 80 Geotechncial StudySouthern Slide Area


±

0 0.04 0.08 0.12 0.160.02Miles

MT 80 Geotechncial StudyMiddle Slide Area


±

0 0.015 0.03 0.045 0.060.0075Miles

MT 80 Geotechncial StudyNorthern Slide Area

100

80

75

50

100

90

90

100

3 - 4 - 4

1 - 3 - 2

WH - 1 - 2

1 - 3 - 3

1 - 3 - 7

4 - 10 - 15

6 - 20 - 43

22 - 49 - 50/0.4ft

0.53550.5

2.73548.3

4.53546.5

7.03544.0

9.53541.5

11.43539.6

14.53536.5

18

9

26

20

24

18

12

10

29

25

45

38

17

15

22

22

47

45

41

83

Hollow stem augerswith finger bit.

BASE COURSE, Poorly-Graded GRAVELwith silt and sand (GP-GM), moist, grey tobrown, fine to coarse grained, angular tosubangular, [A-1].FILL, Sandy Lean CLAY with gravel (CL),moist, brown, [A-4/A-6].Lean CLAY (CL), medium stiff, moist, brownto dark brown, [A-4/A-6]. Frequent organics.Clayey SAND (SC), loose, moist, brown,[A-6]. Occasional gravel.Clayey SAND (SC), very loose, moist to wet,brown, [A-4]. Occasional gravel.

Clayey SAND (SC), loose, moist, brown,[A-7]. Occasional gravel.

Lean CLAY with sand (CL), stiff, moist, darkbrown, [A-6].

CLAYSTONE, dark brown to dark grey, verysoft to soft field hardness.

LOG OF BORING

3546.0

3541.0

3536.0

3531.0

3526.0

3521.0

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

5

10

15

20

25

30

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand

Other TestsMaterial Description

(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:19

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ

Abandonment:N/ANotes:

Datum: NAD83

Sheet 1 of 2

System: MT S.P. (E)

Project:

Elevation Source:Plans

Date Started:12/20/16

Project Number:STPX 80-2(4)49

Date Finished:12/21/16

Rig:CME 1050Hammer:AutoBoring Diameter:8"

Drilling Fluid:None

MT 80 Geotechnical Study

UPN:9286000

Logger:KluthDriller: Boyd PLS TRS-QQ: 19N 12E 22 - DB Inclinometer installed after completing boring.

Boring LocationCoordinates

N: 1147513.8 ftE: 1799909.2 ft

Location Source:GPS and Plans

Station:Offset:

270 + 8616 ft R

GroundElevation: 3551 ft

Water Level Observations Remarks:DuringDrilling: Not EncounteredAfterDrilling:

End ofDrilling:

Boring 9286000-1

100

100

100

100

100

17 - 39 - 50/0.3ft

19 - 36 - 50/0.3ft

37 - 50/0.1ft

47 - 50/0.1ft

49 - 50/0.3ft

33.13517.9

50.83500.2

9

9

7

6

7

Set inclinometercasing to 50.0' withsilica sand. Installedflush-mount cover.

CLAYSTONE, continued.

SHALE, dark grey, soft field hardness.

Boring Depth: 50.8 ft, Elevation: 3500.2 ft

LOG OF BORING

3516.0

3511.0

3506.0

3501.0

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

35

40

45

50

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:19

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 2 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KluthDriller: Boyd PLS TRS-QQ: 19N 12E 22 - DB Inclinometer installed after completing boring.


N: 1147513.8 ftE: 1799909.2 ft


Station:Offset:

270 + 8616 ft R

GroundElevation: 3551 ft


End ofDrilling:

Boring 9286000-1

100

80

75

80

90

80

40

60

80

70

9 - 8 - 8

2 - 2 - 3

4 - 10 - 8

5 - 7 - 8

10 - 12 - 18

10 - 14 - 10

WH - 2 - 3

1 - 2 - 4

5 - 9 - 15

9 - 23 - 28

1.53548.4

8.13541.8

13.13536.8

16.73533.2

19.03530.9

27.03522.9

917

16

16

4

8

6

6

23

16

18

17

40

27

23

42

48

50

23

17

15

22

24

24

62

1

45

68

90

93


Mechanicallyprocessed sampleclassified as Fat

BASE COURSE, Clayey GRAVEL with sand(GC), moist, brown, fine to coarse grained,subrounded, [A-2].FILL, Sandy Lean CLAY with gravel (CL),very stiff to medium stiff, moist, dark brown,[A-6].

Well-Graded SAND with gravel (SW),medium dense, dry to moist, tan, fine tocoarse grained, subrounded to subangular,[A-2].

Clayey SAND (SC), medium dense, dry tomoist, tan, fine to coarse grained,subrounded to subangular, [A-4]. Dark brownorganics from 13.1 ft. to 13.5 ft.

Sandy Lean CLAY (CL), medium stiff, moist,grey, [A-7]. Occasional gravel. Occasionalorganics.Lean CLAY (CL), medium stiff to very stiff,moist, grey, [A-7]. Occasional gravel.

CLAYSTONE, dark grey, very soft fieldhardness.

LOG OF BORING

3544.9

3539.9

3534.9

3529.9

3524.9

3519.9

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

5

10

15

20

25

30

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 1 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KloberdanzDriller: Fredrick PLS TRS-QQ: 19N 12E 22 - DB Inclinometer installed after completing boring.


N: 1147485.8 ftE: 1799876.8 ft


Station:Offset:

270 + 7926 ft L

GroundElevation: 3549.9 ft

Water Level Observations Remarks: 24.8 ft., During Drilling, Augers In, 1-24-17DuringDrilling: 27.9 ft (3522.0 ft)AfterDrilling:

End ofDrilling:

Boring 9286000-2

100

100

100

100

70

70

28 - 49 - 50/0.4ft

49 - 50/0.2ft

47 - 50/0.2ft

35 - 50/0.2ft

13 - 50/0.4ft

40 - 50/0.2ft

36.13513.8

60.73489.2

15

8

7

9

15

18

CLAY (CH), [A-7]

Set inclinometercasing to 60.5' withsilica sand. Installedflush-mount cover.


SHALE, dark grey, very soft field hardness.


LOG OF BORING

3514.9

3509.9

3504.9

3499.9

3494.9

3489.9

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

35

40

45

50

55

60

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 2 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KloberdanzDriller: Fredrick PLS TRS-QQ: 19N 12E 22 - DB Inclinometer installed after completing boring.


N: 1147485.8 ftE: 1799876.8 ft


Station:Offset:

270 + 7926 ft L


Water Level Observations Remarks: 24.8 ft., During Drilling, Augers In, 1-24-17DuringDrilling: 27.9 ft (3522.0 ft)AfterDrilling:

End ofDrilling:

Boring 9286000-2

100

100

60

70

50

60

100

100

100

50/0.4ft

21 - 25 - 8

3 - 4 - 5

1 - 4 - 5

3 - 3 - 5

2 - 6 - 11

4 - 10 - 15

4 - 9 - 14

9 - 16 - 23

0.63638.7

1.73637.6

4.53634.8

22.13617.2

28.33611.0

4

4

14

23

21

19

20

22

18

40

53

54

54

54

49

21

26

27

26

28

27

57

73

91

91

87

86


Mechanicallyprocessed sampleclassified as LeanCLAY (CL), [A-7]

Asphalt.BASE COURSE, Poorly-Graded GRAVELwith silt and sand (GW-GM), [A-1]. Frozen.FILL, Sandy Lean CLAY (CL), hard, dry,brown, [A-6]. Frozen to 3.6 ft.

Fat CLAY (CH), medium stiff to very stiff,moist, brown, [A-7]. Occasional gravel.

CLAYSTONE, dark brown, very soft to softfield hardness.

Silty SHALE, grey, soft field hardness.

LOG OF BORING

3634.3

3629.3

3624.3

3619.3

3614.3

3609.3

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

5

10

15

20

25

30

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ

Abandonment:CuttingsNotes:

Datum: NAD83

Sheet 1 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:TuerDriller: Fredrick PLS TRS-QQ: 19N 12E 22 - DB


N: 1146211 ftE: 1800652.3 ft


Station:Offset:

255 + 8612 ft L



End ofDrilling:

Boring 9286000-3

100

100

100

80

80

23 - 50/0.4ft

31 - 50/0.4ft

40 - 50/0.3ft

31 - 50/0.3ft

31 - 50/0.3ft50.8

3588.5

11

10

9

9

10

42 26 78 Mechanicallyprocessed sampleclassified as SILTw/sand (ML), [A-7]

Silty SHALE, continued.


LOG OF BORING

3604.3

3599.3

3594.3

3589.3

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

35

40

45

50

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ

Abandonment:CuttingsNotes:

Datum: NAD83

Sheet 2 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:TuerDriller: Fredrick PLS TRS-QQ: 19N 12E 22 - DB


N: 1146211 ftE: 1800652.3 ft


Station:Offset:

255 + 8612 ft L



End ofDrilling:

Boring 9286000-3

75

65

65

65

40

40

50

70

30

30

65

25

70

60

50

50

60

75

80

60

4 - 6 - 2

1 - 1 - 2

2 - 7 - 8

3 - 3 - 3

2 - 2 - 3

1 - 2 - 3

1 - 4 - 5

3 - 4 - 7

2 - 4 - 4

2 - 4 - 6

2 - 4 - 5

3 - 4 - 3

2 - 3 - 5

1 - 2 - 3

1 - 3 - 4

2 - 1 - 2

1 - 3 - 3

1 - 3 - 4

2 - 5 - 9

7 - 11 - 16

3.73354.0

27.63330.1

29.73328.0

7

19

7

17

9

23

21

18

20

24

20

20

21

8

23

17

39

20

20

17

45

46

41

40

53

58

20

21

19

18

23

25

64

80

54

58

80

93


FILL, Poorly-Graded GRAVEL with silt andsand (GP-GM), loose, moist, brown to grey,fine to coarse grained, subangular torounded, [A-1].

FILL, Lean CLAY with sand (CL), soft, moist,brown to dark-brown, [A-7].

Medium stiff to stiff. Cobble from 6.2' to 6.5'.

Layers and seams of clayey gravel w/ siltand sand, organics from 8.1' to 13.6'.

Asphalt fragments from 19.8' to 19.9'.

Seam of clayey gravel w/ silt and sand from22.8' to 22.9'.

Soft to medium stiff.

CLAYSTONE, brown to grey, very soft fieldhardness. Seams of light-grey, highly-plastic,Bentonite CLAY from 27.6' to 28.6'.SHALE, dark-grey, very soft to soft fieldhardness. Frequent gypsum.

LOG OF BORING

3352.7

3347.7

3342.7

3337.7

3332.7

3327.7

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

5

10

15

20

25

30

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 1 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KluthDriller: Fredrick PLS TRS-QQ: 19N 12E 15 - CD Inclinometer installed after completing boring.


N: 1150803.5 ftE: 1799397.3 ft


Station:Offset:

309 + 2528 ft L



End ofDrilling:

Boring 9286000-4

75

85

100

100

100

100

100

8 - 14 - 20

9 - 19 - 37

13 - 50/0.3ft

50/0.4ft

50/0.3ft

35 - 50/0.3ft

47 - 50/0.3ft 60.83296.9

17

15

13

8

7

14

16

SHALE, continued.


LOG OF BORING

3322.7

3317.7

3312.7

3307.7

3302.7

3297.7

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

35

40

45

50

55

60

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 2 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KluthDriller: Fredrick PLS TRS-QQ: 19N 12E 15 - CD Inclinometer installed after completing boring.


N: 1150803.5 ftE: 1799397.3 ft


Station:Offset:

309 + 2528 ft L



End ofDrilling:

Boring 9286000-4

80

65

75

75

75

75

75

85

80

85

75

85

90

90

80

1 - 2 - 2

1 - 5 - 4

3 - 3 - 4

5 - 4 - 6

6 - 6 - 4

3 - 4 - 7

1 - 2 - 2

WH - 3 - 6

2 - 5 - 8

4 - 5 - 8

3 - 5 - 9

4 - 5 - 8

3 - 6 - 11

4 - 8 - 12

5 - 10 - 16

2.23309.1

5.93305.4

10.63300.7

12.83298.5

14.43296.9

26.73284.6

20

19

11

8

6

3

20

21

22

22

25

20

19

18

19

18

18

16

23

45

44

44

43

49

13

22

22

21

21

22

16

91

71

86

95

86

Hollow stem augerswith finger bit.Surface slumpmaterial at slide toefrom 0' to 2.2'.

Clayey SANDw/gravel (SC) layerfrom 5.9' to 10.6' iswet.

Lean CLAY (CL), soft, moist to dry, brown todark-brown, [A-6].

Lean CLAY (CL), soft to medium stiff, moist,dark-brown, [A-6].

Gravel layer from 4.7' to 4.8'.

Clayey SAND with gravel (SC), loose tomedium dense, wet, brown to grey, fine tocoarse grained, subangular to rounded, [A-2].

Lean CLAY (CL), stiff, moist to wet,dark-brown, [A-7].

Sandy Lean CLAY (CL), soft, moist,dark-brown, [A-7].

Lean CLAY (CL), stiff, moist, dark-brown,[A-7]. Occasional gravel, organics, andiron-oxide staining.

Very stiff.

CLAYSTONE, dark brown, very soft fieldhardness. Frequent gypsum and iron-oxidestaining.

LOG OF BORING

3306.3

3301.3

3296.3

3291.3

3286.3

3281.3

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

5

10

15

20

25

30

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 1 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KluthDriller: Fredrick PLS TRS-QQ: 19N 12E 15 - CD Inclinometer installed after completing boring and a

monitoring well was installed next to the boring.


N: 1150959.9 ftE: 1799331.1 ft


Station:Offset:

309 + 31197 ft L


Water Level Observations Remarks:DuringDrilling: 5.9 ft (3305.4 ft)AfterDrilling:

End ofDrilling: Not Encountered

Boring 9286000-5

50

50

80

75

6 - 10 - 15

7 - 11 - 15

8 - 9 - 15

5 - 6 - 1046.5

3264.8

15

14

14

17



LOG OF BORING

3276.3

3271.3

3266.3

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

35

40

45

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 2 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KluthDriller: Fredrick PLS TRS-QQ: 19N 12E 15 - CD Inclinometer installed after completing boring and a

monitoring well was installed next to the boring.


N: 1150959.9 ftE: 1799331.1 ft


Station:Offset:

309 + 31197 ft L


Water Level Observations Remarks:DuringDrilling: 5.9 ft (3305.4 ft)AfterDrilling:

End ofDrilling: Not Encountered

Boring 9286000-5

80

80

80

70

80

80

100

100

80

90

3 - 7 - 10

3 - 7 - 11

4 - 8 - 10

4 - 7 - 9

3 - 16 - 29

7 - 12 - 16

12 - 29 - 50/0.4ft

18 - 49 - 50/0.4ft

13 - 25 - 23

8 - 11 - 17

0.83360.6

4.63356.8

8.23353.2

15.63345.8

22.53338.9

15

29

19

18

14

19

13

12

12

29

47

66

59

20

38

23

95

79

98


BASE COURSE, Poorly-Graded GRAVELwith sand (GP), loose, dry, tan, coarsegrained, subangular to subrounded, [A-1].FILL, Silty SAND with gravel (SM), loose tomedium dense, moist, brown, fine grained,subrounded to rounded, [A-4].

FILL, Lean CLAY (CL), very stiff, moist,brown, [A-7]. Occasional gypsum crystals.

Elastic SILT with sand (MH), very stiff, moist,brown to grey, [A-7]. Occasional sand seams. Occasional gypsum crystals.

Occasional gypsum filled fractures.

CLAYSTONE, grey, very soft field hardness.Occasional gypsum filled fractures.

SHALE, grey, very soft field hardness.Occasional gypsum filled fractures.

Wet seam at 27'.

Bentonite layer at 28.9'.

LOG OF BORING

3356.4

3351.4

3346.4

3341.4

3336.4

3331.4

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

5

10

15

20

25

30

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 1 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KloberdanzDriller: Fredrick PLS TRS-QQ: 19N 12E 15 - CD Monitoring well installed after completing boring.


N: 1150783 ftE: 1799369.4 ft


Station:Offset:

308 + 9122 ft L


Water Level Observations Remarks: Wet seam at 27 feet, but did not appear to begroundwater.

DuringDrilling: Not EncounteredAfterDrilling:

End ofDrilling:

Boring 9286000-6

100

100

100

100

100

28 - 27 - 28

32 - 33 - 39

3 - 32 - 50/0.2ft

50/0.4ft

50/0.4ft 50.43311.0

9

10

29

19

16

SHALE, continued.

Occasional shell fragments.

Sandy SHALE, soft field hardness.


LOG OF BORING

3326.4

3321.4

3316.4

3311.4

Sam

ple

Type

Rec

over

y (%

)

RQ

D (%

)Depth(ft)

Elev.(ft)

35

40

45

50

Ope

ratio

n

Blo

w C

ount

Lith

olog

y Depth(ft)

Elev.(ft)

MC

(%)

LL PL

-200

(%)

Qu

(psi

)

DD

(pcf

)

Remarksand


(2)

MD

T L

OG

OF

BO

RIN

G -

MD

T_2

016

+W

ELL

_V1.

GD

T -

3/2

5/20

09

:20

- L:

\PR

OJE

CT

S\2

016

+P

RO

JEC

TS

\928

600

0.G

PJ


Datum: NAD83

Sheet 2 of 2

System: MT S.P. (E)

Project:






Drilling Fluid:None


UPN:9286000

Logger:KloberdanzDriller: Fredrick PLS TRS-QQ: 19N 12E 15 - CD Monitoring well installed after completing boring.


N: 1150783 ftE: 1799369.4 ft


Station:Offset:

308 + 9122 ft L


Water Level Observations Remarks: Wet seam at 27 feet, but did not appear to begroundwater.

DuringDrilling: Not EncounteredAfterDrilling:

End ofDrilling:

Boring 9286000-6

MT80 SI1 A

2/15/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

Profile Change in Inches-1 -0.5 0 0.5 1

MT80 SI1 B

2/15/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50


MT80 SI1 A

2/15/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

Tilt Change in Inches-1 -0.5 0 0.5 1

MT80 SI1 B

2/15/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48


MT80 SI2 A

3/1/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60

Profile Change in Inches-1 0 1 2 3

MT80 SI2 B

3/1/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60


MT80 SI2 A

3/1/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

52

54

56

58

Tilt Change in Inches0 0.5 1 1.5

MT80 SI2 B

3/1/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

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22

24

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28

30

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34

36

38

40

42

44

46

48

50

52

54

56

58


MT80 SI4 A

7/13/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60

Profile Change in Inches0 0.5 1 1.5

MT80 SI4 B

7/13/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

14

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18

20

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24

26

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30

32

34

36

38

40

42

44

46

48

50

52

54

56

58

60


MT80 SI4 A

7/13/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

10

12

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50

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MT80 SI4 B

7/13/2017 7/27/2017 12/6/2017

Dep

th in

Fee

t

2

4

6

8

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MT80 SI5 A

7/17/2017 7/27/2017 12/7/2017

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th in

Fee

t

2

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6

8

10

12

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18

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42

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48

Profile Change in Inches0 0.5 1 1.5

MT80 SI5 B

7/17/2017 7/27/2017 12/7/2017

Dep

th in

Fee

t

2

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6

8

10

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MT80 SI5 A

7/17/2017 7/27/2017 12/7/2017

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th in

Fee

t

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6

8

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18

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MT80 SI5 B

7/17/2017 7/27/2017 12/7/2017

Dep

th in

Fee

t

2

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Documents

Montana Department of Transportation PO Box 201001 Helena, … · 2020-05-05 · slide, geometry of the area outside the toe of the slide, and the gradient of the drainage ditch along