29450 Final Report (Piezometers at Pedestrian Tunnel)_digi.pdf

March 11, 2020

Mr. Rick Massey Toland-Mizell Architects 590 Means Street, NW, Suite 200 Atlanta, Georgia 30318

ECS Project No. 35-29450 Client ID: A399

Reference: Final Report of Geotechnical Engineering Services Piezometers at Pedestrian Tunnel Gainesville, Alachua County, Florida

Dear Mr. Massey:

ECS Florida, LLC (ECS) has completed the requested geotechnical exploration in general accordance with our proposal dated August 8, 2019. This exploration was performed to evaluate the general subsurface conditions and water table elevations near the tunnel.

PROJECT INFORMATION

The general site location is shown on Figure 1. The site is a pedestrian tunnel that connects the VA Hospital with the UF Health Hospital. The tunnel extends beneath SW Archer Road. Water intrusion has occurred in several locations along the tunnel.

ECS initially planned on installing four piezometers to assist with evaluation groundwater levels; however, access to UF Health property was not granted. Therefore, two piezometers were installed on the VA Hospital side of the site.

The ground surface in the vicinity of the piezometers consist of grass, shrubs, and medium trees. An asphalt parking lot is located southeast of the piezometers. A staircase leading down to the tunnel is located just southwest of the piezometers. The bottom of the tunnel was measured to be approximately 18 feet beneath ground surface in the area of the piezometers. Surface water was not observed near the piezometers during any of our site visits.

FIELD EXPLORATION

The piezometers were installed on October 31, 2019. The approximate piezometer locations are indicated on the attached Field Exploration Plan (Figure 2). The piezometers were installed within 5 feet of the tunnel outside walls. Our personnel determined the locations using taped measurements from existing roadways and survey controls adjacent to the site. The piezometer locations on the referenced Field Exploration Plan should be considered accurate only to the degree implied by the method of measurement used.

The piezometers were installed by first performing Standard Penetration Test (SPT) borings, drilled to depths of approximately 25 to 30 feet below the existing ground surface, in general accordance with the methodology outlined in ASTM D 1586 to explore the subsurface conditions within the area of the proposed structure. Split-spoon soil samples recovered during performance of the borings were visually classified in the field and representative portions of the samples were transported to our laboratory for further evaluation.

Piezometers at Pedestrian Tunnel March 11, 2020 ECS Project No.: 35-29450 Page 2

After performing the SPT borings, the piezometer casings were installed into the open hole, and backfilled with clean sand to prevent the migration of silt and clay fines into the well screen. The piezometers were capped beneath grade to allow for regular lawn maintenance.

GENERAL SUBSURFACE CONDITIONS

It should be understood that the soil conditions will vary between the boring locations. The following table summarizes the soil conditions encountered.

GENERAL SOIL PROFILE

TYPICAL DEPTH (ft)

SOIL DESCRIPTION USCS(1)

FROM TO

Ground Surface 15-20 SILTY AND CLAYEY SANDS, very loose to loose, various amounts of gravel, moist to wet

SP-SM, SP-SC, SM, SC

15-20 25-30 FAT CLAY, interbedded strata of clayey sands, soft to firm and medium dense, various amounts of limestone, moist

CH, SC

(1) Unified Soil Classification System

GROUNDWATER LEVELS

Groundwater was encountered in piezometer PZ-1 and recorded at the time of drilling at 9 feet below the existing ground surface. Groundwater was not encountered in piezometer PZ-2 at the time of drilling. We note that groundwater levels will fluctuate due to seasonal climatic variations, surface water runoff patterns, construction operations, and other interrelated factors.

A total of four site visits to record groundwater levels were performed. The groundwater levels within the piezometers are summarized in the table below:

GROUNDWATER LEVELS

PIEZOMETER

DATE AND DEPTH (feet beneath grade)

ATD(1) 11/5/2019 11/11/2019 11/20/2019 11/27/2019

PZ-1 9 23.8 21.1 15 18.5

PZ-2 NE(2) >25 >25 >25 >25

(1) At Time of Drilling

(2) Not Encountered

A site survey was not available to our office at the time of this report preparation. However based on publically available information, the site grades are relatively level and the existing ground surface grades are on the order of 105 feet. The Floridan Aquifer is estimated to be at an elevation of approximately 50 feet1.

Based on the above published information and data collected on-site, it is our opinion the groundwater table at piezometer PZ-1 is a perched condition that is developing within sand seams and on top of perforated

1 Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2009, U.S. Geological Survey.

Piezometers at Pedestrian Tunnel March 11, 2020 ECS Project No.: 35-29450 Page 3 confining soils. Groundwater levels at the site fluctuate greatly depending upon the amount of rainfall experienced by the site.

REPORT LIMITATIONS

Our geotechnical exploration has been performed and our findings obtained in accordance with generally accepted geotechnical engineering principles and practices. ECS is not responsible for any independent conclusions, interpretation, opinions, or recommendations made by others based on the data contained in this report.

Our scope of services was intended to explore the soil conditions within the upper 30 feet below ground surface. Our scope of services does not address geologic conditions, such as sinkholes or soil conditions existing below the depth of the soil borings.

This report does not reflect any variations that may occur adjacent to or between soil borings. The discovery of any site or subsurface condition during construction that deviates from the data obtained during this geotechnical exploration should be reported to us for our evaluation.

We appreciate the opportunity to be your geotechnical consultant on this phase of the project and look forward to providing the materials testing and observation that may be required during the remediation phase. If you have any questions, or if we may be of any further service, please contact us.

Very truly yours, ECS FLORIDA, LLC

Corey A. Dunlap, P.E. David Spangler, P.E.

Senior Engineer Principal Engineer Registered Florida No. 77678 Registered Florida No. 58770 cdunlap@ecslimited.com dspangler@ecslimited.com

Distribution: Rick Massey – Toland-Mizzell Architects 1 pdf

ATTACHMENTS

Figures

Figure 1 Site Location Plan Figure 2 Field Exploration Plan

Appendices

Appendix A Soil Boring Logs Field Exploration Procedures Key to Soil Classification mailto:cdunlap@ecslimited.com mailto:dspangler@ecslimited.com

FIGURES

Figure 1 Site Location Plan Figure 2 Field Exploration Plan

Service Layer Credits: Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China

²

TOLAND MIZELL MOLNER, LLC

PIEZOMETERS AT PEDESTRIAN

1601 SW ARCHER ROAD, GAINESVILLE, FLORIDA

Figure 1 - Site Location Plan

0 2,0001,000 Feet

12/3/2019

ENGINEER

SCALE

35:29450

PROJECT NO.

SHEET

DATE

DS05

1 " = 1000 '

Service Layer Credits: Esri, HERE, Garmin, (c) OpenStreetMap contributors

²

Legend

Approximate Piezometer Locations (2 total)

TOLAND MIZELL MOLNER, LLC

PIEZOMETERS AT PEDESTRIAN

1601 SW ARCHER ROAD, GAINESVILLE, FLORIDA

Figure 2 - Field Exploration Plan

0 10050 Feet

12/3/2019

ENGINEER

SCALE

35:29450

PROJECT NO.

SHEET

DATE

DS05

1 " = 50 '

APPENDIX A

Soil Boring Logs Field Exploration Procedures Key to Soil Classification

AC

AC

SS

SS

SS

SS

SS

SS

(SP-SM) SAND WITH SILT, dark gray, moist

(SP-SC) SAND WITH CLAY AND GRAVEL,

brown and gray, moist

(SC) CLAYEY SAND, gray and brown, moist, very loose to loose

(SM) SILTY SAND, gray and brown, wet, loose, contains trace clay

(SM) SILTY SAND, brown, wet, loose

(CH) FAT CLAY, brown, moist, firm, contains trace limestone

(CH) FAT CLAY, green, moist, soft

CLIENT

Toland Mizell Molner, LLC

Job #:

35:29450

BORING #

PZ-1

SHEET

PROJECT NAME

Piezometers at Pedestrian Tunnel

ARCHITECT-ENGINEER

SITE LOCATION

1601 SW Archer Road, Gainesville, Alachua County, FL

NORTHING EASTING STATION

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN-SITU THE TRANSITION MAY BE GRADUAL.

WL 9 WS WD BORING STARTED 10/31/2019 CAVE IN DEPTH

WL(SHW) WL(ACR) BORING COMPLETED 10/31/2019 HAMMER TYPE Manual

WL RIG FOREMAN ML DRILLING METHOD Mud RotaryDRILLING METHOD Mud Rotary

D E

P T

H

F T

S A

M P

L E

N O

S A

M P

L E

T Y

P E

S A

M P

L E

D

IS

T

(I N

R E

C O

V E

R Y

IN

SURFACE ELEVATION

DESCRIPTION OF MATERIAL

W A

T E

R L

E V

E L S

E L E

V A

T

IO

N

F T

B L O

W S

/6

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS

BOTTOM OF CASING LOSS OF CIRCULATION

CALIBRATED PENETROMETER TONS/FT2

PLASTIC

LIMIT %

WATER

CONTENT %

LIQUID

LIMIT %

ROCK QUALITY DESIGNATION & RECOVERY

RQD% REC.%

STANDARD PENETRATION

BLOWS/FT

AC

AC

SS

SS

SS

SS

SS

SS

SS

(SP-SM) SAND WITH SILT, dark gray, moist

(SC) CLAYEY SAND WITH GRAVEL, brown, moist, loose

(CH) SANDY FAT CLAY, brown, moist, soft

LIMESTONE, white, very soft, slightly weathered

(CH) FAT CLAY, brown, moist, soft

(CH) FAT CLAY, green, moist, firm

(SC) CLAYEY SAND, light gray, moist, medium dense

CLIENT

Toland Mizell Molner, LLC

Job #:

35:29450

BORING #

PZ-2

SHEET

PROJECT NAME

Piezometers at Pedestrian Tunnel

ARCHITECT-ENGINEER

SITE LOCATION

1601 SW Archer Road, Gainesville, Alachua County, FL

NORTHING EASTING STATION

THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL TYPES. IN-SITU THE TRANSITION MAY BE GRADUAL.

WL NE WS WD BORING STARTED 10/31/2019 CAVE IN DEPTH

WL(SHW) WL(ACR) BORING COMPLETED 10/31/2019 HAMMER TYPE Manual

WL RIG FOREMAN ML DRILLING METHOD Mud RotaryDRILLING METHOD Mud Rotary

D E

P T

H

F T

S A

M P

L E

N O

S A

M P

L E

T Y

P E

S A

M P

L E

D

IS

T

(I N

R E

C O

V E

R Y

IN

SURFACE ELEVATION

DESCRIPTION OF MATERIAL

W A

T E

R L

E V

E L S

E L E

V A

T

IO

N

F T

B L O

W S

/6

10 20 30 40 50+

20% 40% 60% 80% 100%

1 2 3 4 5+

ENGLISH UNITS

BOTTOM OF CASING LOSS OF CIRCULATION

CALIBRATED PENETROMETER TONS/FT2

PLASTIC

LIMIT %

WATER

CONTENT %

LIQUID

LIMIT %

ROCK QUALITY DESIGNATION & RECOVERY

RQD% REC.%

STANDARD PENETRATION

BLOWS/FT

FIELD EXPLORATION PROCEDURES

Standard Penetration Test (SPT) Borings

The Standard Penetration Test (SPT) borings were made in general accordance with the latest revision of ASTM D 1586, “Penetration Test and Split-Barrel Sampling of Soils”. The borings were advanced by rotary (or “wash-n-chop”) drilling techniques. At 2 ½ to 5 foot intervals, a split-barrel sampler inserted to the borehole bottom and driven 18 inches into the soil using a 140 pound hammer falling on the average 30 inches per hammer blow. The number of hammer blows for the final 12 inches of penetration is termed the “penetration resistance, blow count, or N-value”. This value is an index to several in-place geotechnical properties of the material tested, such as relative density and Young’s Modulus.

After driving the sampler 18 inches (or less if in hard rock-like material), the sampler was retrieved from the borehole and representative samples of the material within the split-barrel were containerized and sealed. After completing the drilling operations, the samples for each boring were transported to our laboratory where they were examined by our engineer in order to verify the driller’s field classification. The retrieved samples will be kept in our facility for a period of six (6) months unless directed otherwise.

Silts and Clays

Consistency

Safety Hammer SPT N-Value (Blow/Foot)

Automatic Hammer SPT N-

Value (Blow/Foot)

Very Soft Less than 2 Less than 1

Soft 2 – 4 1 – 3

Firm 4 – 8 3 – 6

Stiff 8 – 15 6 – 12

Very Stiff 15 – 30 12 – 24

Hard Greater than 30 Greater than 24

SILT/CLAY DESCRIPTION

MODIFIERS

Modifier Silt/Clay Content

Trace <5% With 5% to12%

Silty/Clayey 13% to 35%

Very >35%

ORGANIC MATERIAL MODIFIERS

Modifier Organic Content

Trace 1% to 2% Few 2% to 4%

Some 4% to 8%

Many >8%

KEY TO SOIL CLASSIFICATION

Description of Compactness or Consistency in Relation

To Standard Penetration Resistance

Granular Materials

Relative Density

Safety Hammer SPT N-Value (Blow/Foot)

Automatic Hammer SPT N-Value (Blow/Foot)

Very Loose Less than 4 Less than 3

Loose 4 – 10 3 – 8

Medium Dense 10 – 30 8 – 24

Dense 30 – 50 24 – 40

Very Dense Greater than 50 Greater than 40

DESCRIPTION OF SOIL COMPOSITION**

(Unified Soil Classification System)

LABORATORY CLASSIFICATION CRITERIA

MAJOR DIVISION

Group

Symbol

FINER THAN

200 SIEVE %

SUPPLEMENTARY

REQUIREMENTS

SOIL DESCRIPTION

GW <5*

D60/D10 greater than 4, 2 / (D x D ) between 1 & 3 Well graded gravels, sandy gravels

Gravelly soils (over half of

D30 60 10

Coarse coarse fraction larger than

GP <5*

Not meeting above gradation for GW

Gap graded or uniform gravels, sandy gravels grained (over 50% by weight coarser

No. 4) GM >12* PI less than 4 or below A-line Silty gravels, silty sandy gravels

GC >12* PI over 7 above A-line Clayey gravels, clayey sandy gravels

D60/D10 greater than 6, than No.

SW <5*

D 2 / (D x D ) between 1 & 3 Well graded sands, gravelly sands

200 sieve) Sandy soils (over half of coarse fraction finer than

30 60 10

SP <5*

Not meeting above gradation requirements

No. 4) SM >12* PI less than 4 or below A-line Silty sands, silty gravelly sands

SC >12* PI over 7 and above A-line Clayey sands, clayey gravelly sands

Fine

Low compressibility

ML Plasticity chart

Silts, very fine sands, silty or clayey fine sands, micaceous silts grained (over 50% by weight finer than

(liquid limit less than 50)

CL Plasticity chart Low plasticity clays, sandy or silty clays

OL Plasticity chart, organic odor or color Organic silts and clays of low plasticity

Micaceous silts, diatomaceous silts, No. 200 sieve)

High compressibility

MH Plasticity chart volcanic ash

(liquid limit more than 50)

CH Plasticity chart Highly plastic clays and sandy clays

OH Plasticity chart, organic odor or color Organic silts and clays of high plasticity

Soils with fibrous organic matter PT Fibrous organic matter; will char, burn or glow Peat, sandy peats, and clayey peat

* For soils having 5 to 12 percent passing the No. 200 sieve, use a dual symbol such as SP-SM.

** Standard Classification of Soils for Engineering Purposes (ASTM D 2487)

SAND/GRAVEL DESCRIPTION

MODIFIERS

Modifier Sand/Gravel

Content

Trace <15%

With 15% to 29%

Sandy/Gravelly >29%