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Memorandum

To: John Stapleton (PIVOT)

From: Evan Garich, Kyle Romney

Date: April 21, 2016

Subject: Geotechnical Investigation for the LTD Glenwood Facility Bus Lot Expansion & Facilities Management Crew Space, Glenwood, Oregon

This memorandum describes the geotechnical investigation, infiltration and laboratory test results, and final design recommendations pertaining to the Lane Transit District (LTD) Glenwood Facility Bus Lot

project site, located at 3500 East 17th Avenue, Eugene, OR, and is intended to be used to supplement previous geotechnical investigations (Attachment E):

“Foundation Investigation Proposed Bus Maintenance and Operations Facility Lane Transit

District Eugene, Oregon” dated March 6, 1987; performed by L.R. Squire Associates “Geotechnical Evaluation Update LTD Fleet Building Remodel-Expansion Eugene, Oregon” dated

April 1, 2009; performed by Professional Service Industries (PSI)

PROJECT INFORMATION

On Friday, February 12, 2016, a geotechnical site investigation was conducted in the proposed facilities

expansion area (unpaved) on the east side of the LTD Glenwood Facility. Dan J Fischer Excavating was the on-site contractor who performed the test pit excavations. Test pits were advanced with a rubber tracked Hitachi EX30 mini excavator. Kyle Romney was the on-site representative for WSP | Parsons

Brinckerhoff (PB) logging soil stratigraphy, soil samples, and performing infiltration tests. A total of four (4) test pits and four (4) infiltration tests were performed. Carlson Testing was used to perform laboratory tests on soil samples (Attachment C).

TEST PITS

Test pit locations are shown in Attachment A. Test pits generally had a similar soil stratigraphy consisting of the following layers (from top to bottom):

a) Topsoil (1” thick)

b) Clayey gravel fill (1 to 1.5 feet thick) c) Soft to stiff, gray, clayey silt to silty clay (0.5 feet thick) d) Stiff, brown, silt (1 to 2 feet thick)

e) Gravel (>3 feet thick)

Test pits were excavated to approximate depths of 7 feet at TP-1 and TP-3 and 2.5 feet at TP-2 and TP-4; all terminating at or within the gravel layer with the exception of TP-2 which terminated in the silt layer.

Ground water was encountered at a depth of 7 feet at TP-1 and TP-3, at which point excavation stopped

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because the sides of the gravel layer were caving at a rate faster than the material could be removed.

Test pit logs are provided in Attachment B.

INFILTRATION

Infiltration tests were performed at each of the test pit locations at a depth of 2.5 feet with the exception of

TP-3 being performed at 3.5 feet. Tests were performed in the gravel layer at TP-1 and TP-4 and the silt

layer at TP-2 and TP-3. The EPA falling head percolation test procedure (EPA, 1980) methodology was

followed for each infiltration test, per Surface Infiltration Facility Requirements from the City of Springfield

Storm Water Design Standards. Infiltration tests in the gravel layer had a measured average infiltration

rate of 148 inches per hour. Infiltration tests in the stiff, silt layer had a measured average infiltration rate

of 6.5 inches per hour. The Surface Infiltration Facility Requirements from the City of Springfield Storm

Water Design Standards specify a minimum factor of safety of two and limit the design infiltration rate to

10 inches per hour. The recommended design infiltration rate is 10 inches per hour for the gravel layer

and 3.25 inches per hour for the silt layer. Infiltration test logs are provided in Attachment B. It should be

noted that ponding on the ground surface was prevalent across the site due to recent storm events.

CONCLUSIONS AND RECOMMENDATIONS

After reviewing the previous geotechnical investigation reports by L.R. Squire Assoc. and PSI, it is our

opinion that the previous conclusions and recommendations are applicable, excluding seismic design

factors (provided below), to the proposed Bus Lot Expansion and construction of the Facilities

Management Crew Space assuming the site plan and design loads do not change significantly from the

current design. Additionally, we recommend that all foundation excavations be monitored and examined

by a qualified geotechnical engineer to document competent foundation soil material is indeed present.

Seismic Design Recommendations

The USGS seismic design maps tool was employed, using ASCE 7-10 (with 2013 errata), and the below

seismic design parameters are recommended for building design at the LTD Glenwood Facility. Site

Class D – “Stiff Soil” was selected based on the available information provided in the geotechnical

investigations. These parameters incorporate the potential known sources that could induce ground

shaking at the project site. The report created from the USGS seismic design maps tool is provided in

Attachment D.

Ss = 0.751 g

S1 = 0.395 g

PGA = 0.361 g

Seismic Design Category = D

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ATTACHMENTS

Attachment A – Site Layout Plan View

Attachment B – Test Pit Logs and Infiltration Test Field Measurements and Calculations

Attachment C – Soil Sample Laboratory Test Report

Attachment D – USGS Seismic Design Map Report

Attachment E – Previous Geotechnical Investigation Reports

REFERRENCES

Design Manual – Onsite Wastewater Treatment and Disposal Systems, EPA, 1980

City of Springfield Storm Water Design Standards, 2012

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ATTACHMENT A – SITE LAYOUT PLAN VIEW

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ATTACHMENT B – TEST PIT LOGS AND INFILTRATION TEST FIELD MEASUREMENTS AND CALCULATIONS

PROJECT:

0.0 TOPSOILCLAYEY GRAVEL with COBBLES (GC) brown, moist, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded, iron oxide staining (fill)

0.5

1.0

SILTY GRAVEL with SAND (GM) gray, moist, loose, some sand, 3/4" gravel clasts, trace claySILTY CLAY to CLAYEY SILT (ML-CL)

1.5 gray, moist, soft to stiffSILT (ML) brown, moist, stiff, some fine sand

2.0

2.5POORLY GRADED GRAVEL with SAND (GP) Infiltration Test performed @ 2.5 feet brown, moist, med dense, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0 Bottom of excavation @ 7 feet. GWT encountered @ 7 feet

LTD FMCS LOCATION: Eugene, OR

CONTRACTOR:

WATER LEVELS: 2/12/2016 09:00START:

EQUIPMENT: Hitachi EX30 mini excavator

7 feet

TEST PIT LOG

TP-1 BORING NUMBER: PROJECT NUMBER:

OF180492B 1SHEET

REMARKS

2/12/2016 10:11END: K. RomneyLOGGER:

Dan J. Fischer Excavating, Inc., Banks, ORELEVATION: n/a

3

Gra

b

2

Gra

b

1

Gra

b

DE

PT

H B

EL

OW

S

UR

FA

CE

(ft)

DESCRIPTION

LO

CA

TIO

N

NU

MB

ER

TY

PE

SAMPLE

PROJECT:

0.0 TOPSOILCLAYEY GRAVEL with COBBLES (GC) brown, moist, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded, iron oxide staining (fill)

0.5

1.0SILTY GRAVEL with SAND (GM) gray, moist, loose, some sand, 3/4" gravel clasts, trace claySILTY CLAY to CLAYEY SILT (ML-CL) gray, moist, soft to stiff

1.5 SILT (ML) brown, moist, stiff, some fine sand

2.0

2.5Infiltration Test performed @ 2.5 feetBottom of excavation @ 2.5 feet

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

Eugene, OR

CONTRACTOR: Dan J. Fischer Excavating, Inc., Banks, OR

PROJECT NUMBER: BORING NUMBER: SHEET

80492B TP-2 1 OF 1

TEST PIT LOG

3

Gra

b

2/12/2016 10:20 END: 2/12/2016 12:15

DESCRIPTION

SAMPLE

REMARKS

LO

CA

TIO

N

WATER LEVELS: START:

2

Gra

b

ELEVATION: n/a

LTD FMCS

EQUIPMENT: Hitachi EX30 mini excavator

Not encountered

LOCATION:

1

Gra

b

NU

MB

ER

TY

PE

LOGGER: K. Romney

DE

PT

H B

EL

OW

S

UR

FA

CE

(ft)

PROJECT:

0.0 TOPSOILCLAYEY GRAVEL with COBBLES (GC) brown, moist, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded, iron oxide staining (fill)

0.5

1.0

1.5

2.0SILTY GRAVEL with SAND (GM) gray, moist, loose, some sand, 3/4" gravel clasts, trace claySILTY CLAY to CLAYEY SILT (ML-CL) gray, moist, soft to stiff

2.5 SILT (ML) brown, moist, stiff, some fine sand Infiltration Test performed @ 2.5 feet

3.0

3.5

4.0

4.5POORLY GRADED GRAVEL with SAND (GP) brown, moist, med dense, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded

5.0

5.5

6.0

6.5

7.0 Bottom of excavation @ 7 feet. GWT encountered @ 7 feet

PROJECT NUMBER: BORING NUMBER: SHEET

80492B TP-3 1 OF 1

TEST PIT LOG

REMARKS

LO

CA

TIO

N

WATER LEVELS: START:

LTD FMCS

EQUIPMENT: Hitachi EX30 mini excavator

ELEVATION: n/a

4

Gra

b

3

Gra

b2

Gra

b

1

Gra

b

NU

MB

ER

TY

PE

2/12/2016 10:54

DE

PT

H B

EL

OW

S

UR

FA

CE

(ft)

DESCRIPTION

SAMPLE

7 feet

LOCATION: Eugene, OR

CONTRACTOR: Dan J. Fischer Excavating, Inc., Banks, OR

END: 2/12/2016 12:43 LOGGER: K. Romney

PROJECT:

0.0 TOPSOILCLAYEY GRAVEL with COBBLES (GC) brown, moist, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded, iron oxide staining (fill)

0.5

1.0

SILTY GRAVEL with SAND (GM) gray, moist, loose, some sand, 3/4" gravel clasts, trace claySILTY CLAY to CLAYEY SILT (ML-CL)

1.5 gray, moist, soft to stiffSILT (ML) brown, moist, stiff, some fine sand

2.0

2.5POORLY GRADED GRAVEL with SAND (GP) Infiltration Test performed @ 2.5 feet brown, moist, med dense, fine to coarse gravel, up to 6" cobbles, clasts are subrounded to rounded Bottom of excavation @ 2.7 feet

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

PROJECT NUMBER: BORING NUMBER: SHEET

80492B TP-4 1 OF 1

TEST PIT LOG

REMARKS

LO

CA

TIO

N

WATER LEVELS: START:

LTD FMCS

EQUIPMENT:

ELEVATION: n/a

Gra

b

4

2

Gra

b

3

Gra

b

NU

MB

ER

TY

PE

1

Gra

b

2/12/2016 12:17

DE

PT

H B

EL

OW

S

UR

FA

CE

(ft)

DESCRIPTION

SAMPLE

Not encountered

LOCATION: Eugene, OR

CONTRACTOR: Dan J. Fischer Excavating, Inc., Banks, OR

END: 2/12/2016 12:31 LOGGER: K. Romney

Infiltration Test Field Measurments and Calculations 1 of 1

Location Test # Time

Time 

interval 

(min)

Measurement 

(feet)

Drop in 

Water 

Level (ft)

Infiltration 

Rate (in/hr)

Average 

Infiltration 

Rate (in/hr)

TP‐1 1 9:37 AM 3.10

9:38 AM 0:01 3.70 0.60 432.0

9:39 AM 0:01 3.87 0.17 122.4

2 9:41 AM 3.35

9:42 AM 0:01 3.70 0.35 252.0

9:43 AM 0:01 3.87 0.17 122.4

3 9:46 AM 3.05

9:47 AM 0:01 3.55 0.50 360.0

9:48 AM 0:01 3.75 0.20 144.0

4 9:51 AM 3.15

9:52 AM 0:01 3.51 0.36 259.2

9:53 AM 0:01 3.70 0.19 136.8

9:54 AM 0:01 3.87 0.17 122.4 127.8

TP‐2 1 11:03 AM 2.58

11:13 AM 0:10 2.83 0.25 18.0

11:23 AM 0:10 2.98 0.15 10.8

11:36 AM 0:13 3.17 0.19 10.5

11:46 AM 0:10 3.29 0.12 8.6

11:55 AM 0:09 3.39 0.10 8.0

12:05 PM 0:10 3.48 0.09 6.5 6.5

TP‐3 1 11:05 AM 4.98

11:15 AM 0:10 5.13 0.15 10.8

11:25 AM 0:10 5.15 0.02 1.4

11:36 AM 0:11 5.20 0.05 3.3

11:47 AM 0:11 5.23 0.10 6.5

11:57 AM 0:10 5.26 0.11 7.9

12:07 PM 0:10 5.29 0.09 6.5 6.5

TP‐4 1 12:20 PM 3.30

12:21 PM 0:01 3.70 0.40 288.0

12:21 PM 0:00 3.80 0.10 144.0

2 12:22 PM 3.25

12:23 PM 0:01 3.60 0.35 252.0

12:24 PM 0:01 3.90 0.30 216.0

3 12:25 PM 2.80

12:26 PM 0:01 3.45 0.65 468.0

12:27 PM 0:01 3.65 0.20 144.0 168.0

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ATTACHMENT C – SOIL SAMPLE LABORATORY TEST REPORT

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ATTACHMENT D – USGS SEISMIC DESIGN MAP REPORT

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ATTACHMENT E – PREVIOUS GEOTECHNICAL INVESTIGATION REPORTS