17M7972C_Geotechnical_Letter_of_Results_FS_189-A.PDF

17M7972C Page 1 of 3

September 10, 2018 TPT Project 17M7972C

Martha Alunkal, PE

WSP USA

13530 Dulles Technology Drive, Suite 300

Herndon, Virginia 20171

Re: Letter of Results

DSR FS 189-A

Bridge over Brunsweiler River

Town of Marengo, Ashland County, Wisconsin

Dear Ms. Alunkal:

This letter presents the results of our field exploration performed at the bridge over the Brunsweiler River located on FS 189 (Spring Brook Road) in the Town of Marengo, Ashland County, Wisconsin. This work covers DSR FS 189-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 bridge pile encapsulation, 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 large spread scour behind the west abutment which moved the riprap downstream. After an inspection of the bridge after the rain event it was discovered that two of the timber piles were cracked/crushed during installation and are planned to be repaired. 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 8th, 2018 and June 12th, 2018 using our

Geoprobe Systems 7822DT track mounted drill rig. Both SPT borings were performed to a nominal depth of 31 feet using hollow stem auger drilling methods. Boring FS 189-A (East) was performed at the east end of the bridge and Boring FS 189-A (West) was performed at the west end of the bridge; 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 3451. It is our understanding that this benchmark has an elevation of 1224.4 feet.

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

17M7972C Page 2 of 3

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 three percent to 17 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 in the Appendix.

Table 1: Summary of Sieve Analysis Results

Boring Depth (feet) Description of

Material

% Passing

#200

FS 189-A

(East)

2-3.5 SM (Fill)

AASHTO A-2-4

FS 189-A

(East)

4.5-6 SM (Fill)

AASHTO A-2-4

*SM = Silty Sand

Subsurface Conditions

Bituminous pavement was encountered at the surface to a depth of about six inches in Boring FS 189-A

(West).

Fill soils consisting of silty sand (AASHTO A-2-4) were encountered at the surface or below the bituminous pavement to depths up to 12 feet. Fill soils generally contained gravel, were fine to coarse grained, were brown in color, and ranged from moist to waterbearing.

Peat soils (AASHTO A-8) were encountered below the fill soils in Boring FS 189-A (West) between the depths of 9 feet and 9 ½ feet. Peat soils contained organics, were dark brown in color, and were wet.

Native clayey sand soils (AASHTO A-2-4) were encountered below the peat soils to a depth of 14 feet in

Boring FS 189-A (West). Clayey sand soils contained gravel, were fine to coarse grained, were generally brown in color, and were wet. Based upon results of SPT N-values native clayey sand soils appear to range from loose to medium dense in relative density.

Native silty sand soils (AASHTO A-2-4) were encountered below the clayey sand soils in Boring FS 189-A

(West) and below the fill soils in Boring FS 189-A (East). Silty sand soils generally contained gravel, were 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 medium dense to very dense in relative density.

Poorly graded sand soils (AASHTO A-1-b)were encountered below the silty sand soils in Boring FS 189-A

(West) between the depths of 22 feet and 31 feet. Poorly graded sand soils generally ranged from fine to coarse grained, were brown in color, and were waterbearing. Based upon results of SPT N-values native poorly graded sand soils appear to range from medium dense to very dense in relative density.

17M7972C Page 3 of 3

Groundwater was observed at a depth of 11 feet in Boring FS 189-A (East) and in Boring FS 189-A (West) at a depth of 22 feet while drilling and sampling. Groundwater levels at this site are anticipated to correspond with the surface level of the adjacent Brunsweiler River which had an elevation around 11 feet below our boring locations.

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.

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)

Approximate Boring Location

DRAWN BY: CHECKED BY:

DATE: SCALE:

DRAWING NO:

TPT PROJECT NO:

DRAWING NO:

1/1

REV:

DCS BMC

6/20/18 N/A

17M7972C-01

17M7972C

A

BORING LOCATION SKETCH

DSR FS 189-A

Town of Marengo

Ashland County, Wisconsin

T win

P orts

T esting

N

FS 189-A (EAST)

FS 189-A (WEST)

F

S

S p r i n g

B r o o k

R o a d

B r u n s w e i l e

R i v e

SS

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

4.0

12.0

31.0

(FILL) Poorly Graded Sand with silt and gravel, fine to coarse grained, brown, moist, medium dense to dense

*Percent passing the #200 sieve test performed at 3 feet = 14 (FILL) Silty Sand with Gravel, fine to coarse grained, brown, moist to waterbearing, very loose to medium dense *Sieve analysis performed at 5 feet

*no recovery in sample at 8 feet

(SM) SILTY SAND with Gravel, fine to coarse grained, brown to greyish brown at 29 feet, waterbearing, medium dense to very dense (AASHTO A-2-4)

*pieces of grey fragmented rock in the sample at 30 feet Boring then Backfilled with Bentonite End of Boring

CLIENT:

DSR FS189-A

PROJECT:

5/15/18

11 ft WD

River Elev 1219.4 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 Marengo, Ashland County, Wisconsin

ARCHITECT - ENGINEER:

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES

IN-SITU, THE TRANSITION MAY BE GRADUAL.

05/08/18 05/08/18

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

17M7972C

SA

M

PL

E

N O

D

EP

TH

(f t)

EL

EV

AT

IO

N

(f t)

0.0

10.0

20.0

30.0

1230.8

1220.8

1210.8

1200.8

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 189-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 17M7972C DSR FS189A.GPJ TWINPORT.GDT 7/17/18

G R

AP

H

IC

L

O G

SURFACE ELEVATION:

1230.8 ftST

R

AT

A C

H

AN

G E

D

EP

TH

WOH

50/4

50/3

SS

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

HSA

SS

0.5

7.0

9.0 9.5

14.0

22.0

28.0

31.0

6 Inches of Asphalt Pavement (FILL) Silty Sand with gravel, fine to coarse grained, brown, moist, medium dense

(FILL) Silty Sand, fine to medium grained, brown, wet, medium dense

(PT) PEAT, dark brown, wet (AASHTO A-8) (SC) CLAYEY SAND with Gravel, fine to coarse grained, brown to dark brown, wet, loose to medium dense (AASHTO A-2-4)

(SM) SILTY SAND, trace gravel, fine to coarse grained, brown, waterbearing, medium dense (AASHTO A-2-4)

(SP) POORLY GRADED SAND, trace gravel, fine to coarse grained, brown, waterbearing, medium dense (AASHTO A-1-b)

(SP) POORLY GRADED SAND, fine to medium grained, brown, waterbearing, very dense (AASHTO A-1-b)

Boring then backfilled with bentonite End of Boring

CLIENT:

DSR FS189-A

PROJECT:

5/15/18

22.9 ft WD

River Elev 1219.4 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 Marengo, Ashland County, Wisconsin

ARCHITECT - ENGINEER:

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES

IN-SITU, THE TRANSITION MAY BE GRADUAL.

06/12/18 06/12/18

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

17M7972C

SA

M

PL

E

N O

D

EP

TH

(f t)

EL

EV

AT

IO

N

(f t)

0.0

10.0

20.0

30.0

1231.9

1221.9

1211.9

1201.9

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 189-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 17M7972C DSR FS189A.GPJ TWINPORT.GDT 7/17/18

G R

AP

H

IC

L

O G

SURFACE ELEVATION:

1231.9 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