17M7972D_Geotechnical_Letter_of_Results_FS_196-A.PDF

17M7972D Page 1 of 3

September 10, 2018 TPT Project 17M7972D

Martha Alunkal, PE

WSP USA

13530 Dulles Technology Drive, Suite 300

Herndon, Virginia 20171

Re: Letter of Results

DSR FS 196-A

Bridge over Unnamed Creek

Town of Grand View, Bayfield County, Wisconsin

Dear Ms. Alunkal:

This letter presents the results of our field exploration performed at the bridge over an unnamed creek located on FS 196 (Nowhere Road) in the Town of Grand View, Bayfield County, Wisconsin. This work covers

DSR FS 196-A as part of the WI ERFO FS 2016-1(3) project.

Project

It is our understanding that WSP USA is in the design process for abutment grouting and riprap placement at the above referenced site. It is our understanding that the bridge sustained damage from a large rain event in July 2016. The damage consisted of severe scour undermining the west abutment. It is our understanding that the damage will be repaired by pumping grout underneath the footing and protecting the footing with riprap. As part of the design process geotechnical services were requested.

Our scope of services for this project consisted of performing two (2) Standard Penetration Test (SPT) borings to a depth of 20 feet below river bottom or refusal. We were authorized to proceed with the proposed scope of services in a signed subcontractor agreement dated February 26, 2018.

Field Exploration

Field procedures for this project were performed on May 15th, 2018 using our Geoprobe Systems

7822DT track mounted drill rig. Boring FS 196-A (East) was performed at the east end of the bridge and encountered split spoon refusal at a depth of 6 feet. Multiple offset attempts were performed which encountered auger refusal at a depth of 5 feet. Boring FS 196-A (West) was performed at the west end of the bridge and encountered auger refusal at a depth of 17 feet. Both borings were performed adjacent to the bridge abutments. The boring locations are shown on the Boring Location Sketch attached to this letter. Surface elevations were recorded by our field crew using a surveyors level and rod and were referenced to a benchmark labeled 3550. It is our understanding that this benchmark has an elevation of 1422.9 feet.

1301 N 3 rd St. Superior WI 54880 715 - 392 - 7114 1 - 800 - 373 - 2562 F 715 - 392 - 7163 www.twinportstesting.com

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Laboratory Testing

Results of the field testing and observed subsurface conditions were evaluated to develop a laboratory testing program. The final laboratory testing program included visual classification by a geotechnical engineer, water content testing, and sieve analysis testing.

Laboratory water content testing was performed in general accordance with ASTM D2216 on collected samples from the field exploration. Results of water content tests are shown on the borings logs in the

Appendix. In general water content ranged from five to 53 percent.

Sieve analysis testing was performed in general accordance with ASTM D422 procedures on two samples.

Test results for percent passing the #200 sieve are provided in Table 1 below and on the boring logs in the Appendix. Test results for full gradation sieve testing are attached to this letter.

Table 1: Summary of Sieve Analysis Results

Boring Depth (feet) Description of

Material

% Passing

#200

FS 196-A

(East)

0-2 SM (Fill)

AASHTO A-2-4

FS 196-A

(West)

0-2 SM (Fill)

AASHTO A-2-4

27.3

*SM = Silty Sand

Subsurface Conditions

Fill soils consisting of silty sand (AASHTO A-2-4) were encountered at the surface to depths up to six feet. Fill soils generally contained gravel, were fine to coarse grained, were brown in color, and were moist.

Peat soils (AASHTO A-8) were encountered below the fill soils in Boring FS 196-A (East) between the depths of 5 ½ feet and six feet. Peat soils contained organics, were dark brown in color, and were wet.

Native silty sand soils (AASHTO A-2-4) were encountered below the fill soils in Boring FS 196-A (West) to the boring termination depth of 17 feet. Silty sand soils to a depth of nine feet contained gravel, were fine to coarse grained, were brown in color, and were wet. Silty sand soils below a depth of nine feet were generally fine to coarse grained, were brown in color, and were wet. Based upon results of SPT N-values native silty sand soils appear to range from loose to medium dense in relative density.

Groundwater was not encountered in our borings while drilling and sampling at this site. Groundwater levels at this site are anticipated to correspond with the surface level of the adjacent unnamed creek which had an elevation around seven feet below our boring locations and a surface elevation of 1415.5 feet during field procedures.

General

If you have any questions regarding our results, or if we may be of further service on this project, please call us at 715.392.7114.

17M7972D Page 3 of 3

Twin Ports Testing II, Inc.

Brett Carlson, PE

Project Engineer

Martin L. Halvorson, PE

Senior Engineer

Attachments:

Boring Location Sketch (1 Page)

Boring Logs (2 Pages)

Sieve Analysis (1 Page)

Boring Log Notes (2 Pages)

N

Approximate Boring Location

DRAWN BY: CHECKED BY:

DATE: SCALE:

DRAWING NO:

TPT PROJECT NO:

DRAWING NO:

1/1

REV:

DCS BMC

6/20/2018 N/A

17M7972D-01

17M7972D

A

BORING LOCATION SKETCH

DSR FS 196-A

Town of Grandview

Bayfield County, Wisconsin

T win

P orts

T esting

FS 196-A (EAST)

FS 196-A (WEST)

FS 196

F S

F

S

SS

SS

HSA

SS

5.5 6.0

(FILL) Silty Sand with gravel, fine to coarse grained, brown, moist, loose to medium dense *Sieve analysis test performed at 1 foot

*Auger refusal at 5 feet, moved 2 feet east, auger refusal at 5 feet, move 7 feet east, auger refusal at 5 feet (PT) PEAT, dark brown, wet (AASHTO A-8) *rock fragements in end of sample at 6 feet Boring then Backfilled with Bentonite End of Boring

CLIENT:

DSR FS 196-A

PROJECT:

5/21/18

NE WD

River Elev 1415.5 ft

Autohammer

CAVE IN LEVELWATER LEVEL

SITE LOCATION:

WSP USA

RIGSPT HAMMER

None Encountered

BORING STARTED

CREW CHIEF

MLH

WATER LEVEL

WSP USA Town of Grandview, Bayfield County, Wisconsin

ARCHITECT - ENGINEER:

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES

IN-SITU, THE TRANSITION MAY BE GRADUAL.

05/15/18 05/15/18

REPORT DATE:

7822DT

WATER LEVEL BORING COMPLETED ABBREVIATIONS: ACR-After Casing Removal, BCR-Before Casing Removal, AB-After Boring, WD-While Drilling, WS-While Sampling, NE-None Encountered, DB-Diamond Bit, HSA-Hollow Stem Auger, RB-Rock Bit, SS-Split Spoon, ST-Shelby Tube, PA-Power Auger, MR-Mud Rotary, CS-Continuous, RP-Rock Probe, PH-Percussion Hammer, WL-Water Level, WOH-Weight of Hammer, EIL-Exceeds Instrument Level, TS-Topsoil, PP-Pocket Penetrometer

17M7972D

SA

M

PL

E

N O

D

EP

TH

(f t)

EL

EV

AT

IO

N

(f t)

0.0

10.0

20.0

1422.9

1412.9

1402.9

SA

M

PL

E

D

IS

TA

N

C E

PLASTIC

LIMIT %

TPT Project No.:

UNCONFINED COMPRESSIVE STRENGTH (TONS/FT2)

PERCENT PASSING #200 SIEVE

10 20 30 40 50

1 2 3 4 5

10 20 30 40 50

FS 196-A (East)

See Boring Location Sketch

R

EC

O

VE

R Y

10 20 30 40 50

DESCRIPTION OF MATERIAL

WATER

CONTENT %

LIQUID

LIMIT %

W

AT

ER

L

EV

EL

SA

M

PL

E

TY

PE

BORING LOCATION:

BORING LOG

STANDARD PENETRATION TEST N-VALUE

BOREHOLE LOG 17M7972D DSR FS 196 A.GPJ TWINPORT.GDT 7/9/18

G R

AP

H

IC

L

O G

SURFACE ELEVATION:

1422.9 ftST

R

AT

A C

H

AN

G E

D

EP

TH

51/7

SS

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

6.0

9.0

17.0

(FILL) Silty Sand with gravel, fine to coarse grained, brown, moist, loose to medium dense *Sieve analysis of % passing #200 sieve test performed at 1 foot = 27.3 %

*Apparent cobbles from 5 feet to 7 feet

(SM) SILTY SAND with Gravel, fine to coarse grained, trace organics, dark brown, wet, medium dense (AASHTO A-2-4)

(SM) SILTY SAND, fine to medium grained, brown, wet, loose to medium dense (AASHTO A-2-4)

Auger Refusal at 17 feet Boring then Backfilled with Bentonite End of Boring

CLIENT:

DSR FS 196-A

PROJECT:

5/21/18

NE WD

River Elev 1415.5 ft

Autohammer

CAVE IN LEVELWATER LEVEL

SITE LOCATION:

WSP USA

RIGSPT HAMMER

9 ft ACR

BORING STARTED

CREW CHIEF

MLH

WATER LEVEL

WSP USA Town of Grandview, Bayfield County, Wisconsin

ARCHITECT - ENGINEER:

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES

IN-SITU, THE TRANSITION MAY BE GRADUAL.

05/15/18 05/15/18

REPORT DATE:

7822DT

WATER LEVEL BORING COMPLETED ABBREVIATIONS: ACR-After Casing Removal, BCR-Before Casing Removal, AB-After Boring, WD-While Drilling, WS-While Sampling, NE-None Encountered, DB-Diamond Bit, HSA-Hollow Stem Auger, RB-Rock Bit, SS-Split Spoon, ST-Shelby Tube, PA-Power Auger, MR-Mud Rotary, CS-Continuous, RP-Rock Probe, PH-Percussion Hammer, WL-Water Level, WOH-Weight of Hammer, EIL-Exceeds Instrument Level, TS-Topsoil, PP-Pocket Penetrometer

17M7972D

SA

M

PL

E

N O

D

EP

TH

(f t)

EL

EV

AT

IO

N

(f t)

0.0

10.0

20.0

1422.9

1412.9

1402.9

SA

M

PL

E

D

IS

TA

N

C E

PLASTIC

LIMIT %

TPT Project No.:

UNCONFINED COMPRESSIVE STRENGTH (TONS/FT2)

PERCENT PASSING #200 SIEVE

10 20 30 40 50

1 2 3 4 5

10 20 30 40 50

FS 196-A (West)

See Boring Location Sketch

R

EC

O

VE

R Y

10 20 30 40 50

DESCRIPTION OF MATERIAL

WATER

CONTENT %

LIQUID

LIMIT %

W

AT

ER

L

EV

EL

SA

M

PL

E

TY

PE

BORING LOCATION:

BORING LOG

STANDARD PENETRATION TEST N-VALUE

BOREHOLE LOG 17M7972D DSR FS 196 A.GPJ TWINPORT.GDT 7/9/18

G R

AP

H

IC

L

O G

SURFACE ELEVATION:

1422.9 ftST

R

AT

A C

H

AN

G E

D

EP

TH

BORING LOG NOTES

Water Level Water levels indicated on the boring logs are as measured at stated times. In clean sand soils, the elevations indicated are considered relatively reliable levels. However, in less permeable soils, even after several days of monitoring, accurate determinations may not be possible. Therefore, additional/alternative methods of groundwater elevation monitoring should be sought.

Commonly Used Moisture Conditions of Soils Term Meaning Dry Requires the addition of considerable moisture to attain optimum for compaction Moist Near optimum moisture for compaction Wet Requires drying to attain optimum moisture for compaction Waterbearing Saturated granular soils

Gradation Description and Terminology Soil Type Particle Name Size Range Coarse Grained Soils Boulders Over 12”

Cobbles 3”-12” Gravels #4-3” Gravels – Coarse ¾”-3” Gravels – Fine #4-¾” Sands #200-#4 Sands – Coarse #10-#4 Sands – Medium #40-#10 Sands – Fine #200-#40

Fine Grained Soils Silt 0.005 mm-#200 Clay Less than 0.005 mm

Descriptive Terms of Components Present in Sample (other than ASTM D 2487) Term Percent of Dry Weight Trace 1-5% With 5-12% Some 12-30% And 30-50%

Relative Density of Granular Soils N-Value (SPT) Relative Density Standard “N” Penetration 0-4 Very Loose Blows per foot of a 140 pound hammer 5-10 Loose falling 30” on a 2” outside diameter 11-30 Medium Dense split barrel sampler 31-50 Dense Over 50 Very Dense

Consistency of Cohesive Soils N-Value (SPT) Consistency (Q, tsf or kg/cm2) 0-2 Very Soft Less than 0.25 3-4 Soft 0.25-0.50 5-8 Medium 0.50-1.00 9-15 Stiff 1.00-2.00 16-30 Very Stiff 2.00-4.00 Over 30 Hard 4.00-8.00

UNIFIED SOIL CLASSIFICATION SYSTEM – ASTM D 2487