Report of Geotechnical Study - Port...

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VIRGINIA • NORTH CAROLINA • SOUTH CAROLINA • MARYLAND • DISTRICT OF COLUMBIA

A Minority-Owned Business

Report of Geotechnical Study

Baltimore Sun Consolidation Baltimore, Maryland

F&R Project No. 75V0084

Prepared For:

Bohler Engineering 901 Dulaney Valley Road, Suite 801

Towson, MD 21204

Prepared By: Froehling & Robertson, Inc. 10626 York Road, Suites C-D

Cockeysville, Maryland 21030

October 20, 2017

Bohler Engineering Baltimore Sun Consolidation – Baltimore, MD

F&R Project No. 75V0084 October 20, 2017

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TABLE OF CONTENTS

SECTION PAGE

EXECUTIVE SUMMARY .......................................................................................................................1

1.0 PURPOSE & SCOPE OF SERVICES ..............................................................................................2

2.0 PROJECT INFORMATION ..........................................................................................................3

2.1 SITE DESCRIPTION....................................................................................................................3 2.2 PROPOSED CONSTRUCTION ........................................................................................................3

3.0 EXPLORATION PROCEDURES ...................................................................................................4

3.1 SUBSURFACE EXPLORATION .......................................................................................................4 3.2 INFILTRATION TESTING ..............................................................................................................5 3.3 LABORATORY TESTING ..............................................................................................................5

4.0 REGIONAL GEOLOGY & SUBSURFACE CONDITIONS ..................................................................6

4.1 REGIONAL GEOLOGY ................................................................................................................6 4.2 SUBSURFACE CONDITIONS .........................................................................................................6

4.2.1 General........................................................................................................................6 4.2.2 Surficial Materials ........................................................................................................6 4.2.3 Fill Material .................................................................................................................7 4.2.4 Coastal Plain Soils .......................................................................................................7

4.3 SUBSURFACE WATER ................................................................................................................7 4.4 LABORATORY TEST RESULTS .......................................................................................................8

5.0 GEOTECHNICAL DESIGN RECOMMENDATIONS .........................................................................9

5.1 GENERAL ...............................................................................................................................9 5.2 DESIGN RECOMMENDATIONS FOR FOUNDATION ELEMENTS ...............................................................9 5.3 SUPPORTING ON EXISTING FILL ................................................................................................ 10 5.4 FOUNDATION SETTLEMENT ...................................................................................................... 10 5.5 INFILTRATION PRACTICES ......................................................................................................... 10 5.6 CONCRETE SLAB AND SIDEWALK CONSIDERATIONS ........................................................................ 11 5.7 PAVEMENT CONSTRUCTION ..................................................................................................... 12 5.8 SEISMIC CONSIDERATIONS ....................................................................................................... 14

6.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS .......................................................... 15

6.1 SITE PREPARATION ................................................................................................................ 15 6.2 STRUCTURAL FILL PLACEMENT AND COMPACTION ......................................................................... 16 6.3 FOUNDATION CONSTRUCTION .................................................................................................. 17 6.4 SURFACE/ GROUNDWATER CONTROL ......................................................................................... 17 6.5 TEMPORARY EXCAVATION RECOMMENDATIONS ........................................................................... 18

7.0 CONTINUATION OF SERVICES ................................................................................................ 19

8.0 LIMITATIONS ........................................................................................................................ 20



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APPENDICES APPENDIX I

Site Location Plan Boring Location Plan

APPENDIX II Key to Soil Classification Unified Soil Classification Chart Boring Logs USDA Textural Triangles

APPENDIX III GBA Document “Important Information about Your Geotechnical Engineering Report”



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EXECUTIVE SUMMARY

This Executive Summary is provided as a brief overview of our geotechnical engineering

evaluation for the project and is not intended to replace more detailed information contained

elsewhere in this report. As an overview, this summary inherently omits details that could be

very important to the proper application of the provided geotechnical design recommendations.

This report should be read in its entirety prior to implementation into design and construction.

The subsurface exploration program was performed between the dates of August 13,

2017, and October 3, 2017, and consisted of thirteen test borings designated B-1 through

B-8, and SWM-1 through SWM-5. Borings were drilled to the planned termination depths

of 10 feet or 15 feet. Below the existing ground surface, the borings generally

encountered surficial asphalt materials or organic soils, fill materials, and coastal plain

soils.

We note that existing fill materials were present well below the anticipated foundation

bearing levels for the proposed fuel center support structures. Considering the nature of

the proposed structures and the anticipated loads, we envision that the proposed

structures can be supported on a shallow foundation system bearing on approved existing

fill materials, provided that the risks regarding construction on existing fill materials are

understood and accepted. We recommend that foundations be designed for a net

allowable bearing pressure not to exceed 1,500 pounds per square feet (psf).

The field infiltration test rates at SWM-1, SWM-2, and SWM-3, and the overall average

infiltration rate shown above does not meet or exceed the minimum acceptable rate for

infiltration. Based on the foregoing, infiltration practices are not considered feasible at

the locations and elevations tested. We note that only the infiltration rates recorded at

SWM-4 and SWM-5 exceeded the minimum infiltration rate of 0.52 inches per hour;

however, it should also be understood that the infiltration testing is believed to have been

performed in existing fill materials.

The following Seismic Site Class Definition was established per Section 1613.5.2 of the

2012 International Building Code (IBC). Based on our experience in this area and the data

from our testing and subsurface exploration, a Site Classification “D” should be used for

further evaluations relative to earthquake load design regarding the water storage tank.



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1.0 PURPOSE & SCOPE OF SERVICES

The purpose of the subsurface exploration and geotechnical engineering evaluation was to explore the subsurface conditions in the areas of the proposed Baltimore Sun facility improvements, to conduct infiltration testing for the proposed stormwater management practices and provide geotechnical engineering design and construction recommendations that can be used during the design and construction of the proposed improvements.

F&R’s scope of services included the following:

Coordination utility clearance with Miss Utility, and coordination with a private utility locator for utility clearance;

Review and summarize readily available geologic and subsurface information relative to the project site;

Completion of thirteen (13) standard penetration test borings up to the predetermined depths, ranging from 10 feet to 15 feet, for foundation considerations;

Completion of five (5) standard infiltration tests at a depths ranging from 2 feet to 5.5 feet below existing grades for stormwater management considerations;

Preparation of typed Boring Logs;

Perform laboratory testing consisting of 19 Natural Moisture Content, 5 USDA classification tests, 3 USCS classification tests, 3 standard Proctors, and 3 CBR’s;

Performing a geotechnical engineering evaluation of the subsurface conditions with regard to their suitability for the proposed construction;

Provided recommendations for slab on grade and flexible pavement design and construction;

Provided a seismic site class definition. The seismic site class definition was assigned based on the test boring Standard Penetration Test data and correlations provided in the 2012 IBC;

Evaluate the findings of the infiltration test relative to suitable stormwater management practices;

Provided recommendations regarding the placement and compaction of fill materials required to achieve building pad or site subgrades, including an assessment of the suitability of the on-site soil for re-use as structural fill, and recommendations regarding rock excavation;

Preparation of this geotechnical report by professional engineers.



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Our scope of services did not include survey services, quantity estimates, remedial designs,

preparation of plans or specifications, evaluation or monitoring for environmental contaminants,

slope stability analyses, stormwater management design, evaluations of earthquake motions, the

identification and evaluation of wetlands, or any other scope element not specifically listed above.

2.0 PROJECT INFORMATION

2.1 Site Description

The site is located on the grounds of the existing Baltimore Sun facility at 300 E. Cromwell Street in

Baltimore, Maryland, as shown on the Site Location Plan included in Appendix I of this report. The

project site currently consists of the northern and western portion of the facility grounds which are

primarily grass covered lawns and asphalt paved drive lanes and parking areas. The site sits close to

sea level as it is located in close proximity to the open waters of Winans Cove. Topographically, the

site is generally level with grades sloping very slightly from El 20 in the north down to El 12 in the

southwest. A drainage swale runs the perimeter of the Baltimore Sun facility property which was

observed to have standing water during F&R’s site visits.

2.2 Proposed Construction

Our understanding of the project was developed on the basis of telephone and email

correspondence with you, which included the document entitled “Baltimore-Sun Revised SWM

Facilities.pdf” dated September 25, 2017. We understand that the purpose of the site

reorganization is to consolidate the Baltimore Sun’s operations for the initial phases of the Master

Plan for Port Covington. This will include the construction of new drive lanes and parking areas

around the facility located at 300 East Cromwell Street. Additional site improvements will include

the construction of up to five new storm water management facilities that are planned to implement

infiltration practices and a new fueling station consisting of a canopy structure. Based on our review

of the provided grading plan, relatively minor cuts and fills of up to 5 feet are anticipated.



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3.0 EXPLORATION PROCEDURES

3.1 Subsurface Exploration

The subsurface exploration program was performed between the dates of August 13, 2017, and

October 3, 2017, and consisted of thirteen test borings designated B-1 through B-8, and SWM-1

through SWM-5. Borings were drilled to the planned termination depths of 10 feet or 15 feet. The

locations of the borings are shown on the attached Boring Location Plan (Drawing No. 2). The

planned boring locations were determined and staked in the field by F&R by measuring from existing

site features such as building corners, edges of pavement, etc. Surface elevations at the boring

locations were estimated from the topography indicated on the provided site plans. In

consideration of the methods used in their determination, the test boring locations shown on the

attached boring location plan should be considered approximate.

The test borings were performed in accordance with generally accepted drilling practice using a

truck-mounted CME-55 rotary drill rig equipped with an automatic hammer. Hollow-stem augers

were advanced to pre-determined depths, the center plug was removed, and representative soil

samples were recovered with a standard split-spoon sampler (1 3/8 in. ID, 2 in. OD) in general

accordance with ASTM D 1586, the Standard Penetration Test. The split-spoon sampler was driven

into the soil by freely dropping a weight of 140 pounds from a height of 30 inches. The number of

blows required to drive the split-spoon sampler three consecutive 6-inch increments is recorded,

and the blows of the last two increments are summed to obtain the Standard Penetration Resistance

(N-value). The N-value provides a general indication of in-situ soil conditions and has been correlated

with certain engineering properties of soils.

The test borings were advanced through the soil overburden by soil drilling procedures until the

planned termination depth. Subsurface water level readings were taken in all of the borings

immediately upon completion of the drilling process, upon removal of the augers, and again after

24 hours at some locations. Upon completion of drilling, the boreholes were backfilled with auger

cuttings (soil) and capped with asphalt cold patch, as necessry. Periodic observation of the

boreholes should be performed to monitor subsidence at the ground surface, as the borehole

backfill could settle over time.

Representative portions of the split-spoon soil samples obtained throughout the exploration

program were placed in glass jars and transported to our laboratory. In the laboratory, the soil

samples were evaluated by a member of our engineering staff in general accordance with

techniques outlined in the visual-manual identification procedure (ASTM D 2488). The soil

descriptions and classifications discussed in this report and shown on the attached Boring Logs are



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based on visual observation and should be considered approximate. A copy of the boring logs are

provided and classification procedures are further explained in Appendix II.

Split-spoon soil samples recovered on this project will be stored at F&R’s office for a period of 60

days. After 60 days, the samples will be discarded unless prior notification is provided to us in

writing.

3.2 Infiltration Testing

Infiltration testing was conducted adjacent to boring locations SWM-1 through SWM-5, at depths

ranging from 2 feet to 5.5 feet below existing grades. Infiltration testing was performed in general

compliance with the Maryland Department of Environment (MDE) Stormwater Design Manual. The

cased boreholes were soaked with water to a depth of 2 feet for 24 hours. After this presoaking

period water was added as necessary to the cased borehole to re-establish a depth of 2 feet. Water

level readings were taken every 30 minutes for 4 hours, and the infiltration rate is reported as the

average rate of water drop over the period of the test (inches per hour).

3.3 Laboratory Testing

Representative soil samples were subjected to Water Content (ASTM D 2216), #200 Sieve Wash

(ASTM D 1140), Atterberg Limits (ASTM D 4318), Hydrometer Analysis (ASTM D 422), standard

Proctor (ASTM D698) and CBR (ASTM D1883) to substantiate the visual classifications and assist

with the estimation of the soils’ pertinent engineering properties. The results are shown in

Section 4.4.



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4.0 REGIONAL GEOLOGY & SUBSURFACE CONDITIONS

4.1 Regional Geology

Information obtained from the Geologic Map of Maryland (1968) indicates that this area is underlain

by Lowland Deposits of the Pleistocene Epoch, which is composed of gravel, sand, silt and clay soils.

These coastal plain deposits are typically medium-to coarse-grained sand and gravel; cobbles and

boulders near the base; commonly contains reworked Eocene glauconite; varicolored silts and clays,

brown to dark gray lignitic Silty Clay.

4.2 Subsurface Conditions

4.2.1 General

The subsurface conditions discussed in the following paragraphs and those shown on the attached

Boring Logs represent an estimate of the subsurface conditions based on interpretation of the

boring data using normally accepted geotechnical engineering judgments. The transitions between

different soil strata are usually less distinct than those shown on the boring logs. Sometimes the

relatively small sample obtained in the field is insufficient to definitively describe the origin of the

subsurface material. In these cases, we qualify our origin descriptions with “possible” before the

word describing the material’s origin (i.e. possible alluvium, etc.). Although individual soil test

borings are representative of the subsurface conditions at the boring locations on the dates shown,

they are not necessarily indicative of subsurface conditions at other locations or at other times. Data

from the specific soil test borings are shown on the attached Boring Logs in Appendix II.

Below the existing ground surface, the borings generally encountered surficial materials, fill, and

coastal plain soils. These materials are generally discussed in the following paragraphs.

4.2.2 Surficial Materials

Surficial organic soils were encountered in each of the borings, except B-3 and B-8, and extended to

depths of 2 to 3 inches. Surficial organic soil is typically a dark-colored soil material containing roots,

fibrous matter, and/or other organic components, and is generally unsuitable for engineering

purposes. F&R has not performed any laboratory testing to determine the organic content or other

horticultural properties of the observed surficial organic soil materials. Therefore, the term surficial

organic soil is not intended to indicate a suitability for landscaping and/or other purposes. The

surficial organic soil depths provided in this report are based on driller observations and should be

considered approximate. We note that the transition from surficial organic soil to underlying

materials may be gradual, and therefore the observation and measurement of surficial organic soil

depths is subjective. Actual surficial organic soil depths should be expected to vary. Borings B-3 and

B-8 encountered approximately 6 inches of surficial asphalt pavement underlain by 6 inches of

subbase gravel.



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4.2.3 Fill Material

Soils considered to be Fill Material were encountered underlying the surficial materials described

above in each of the soil borings, to depths ranging from 2.5 feet to 13.5 feet. Fill may be any

material that has been transported and deposited by man. Possible fill materials, not clearly

distinguishable from possible coastal plain soils, were encountered at depths of 8.5 feet to 13.5 feet

in borings B-4 and B-5, 2.5 feet to 8.5 feet in boring SWM-5, and 8.5 feet to the boring termination

depth of 15 feet in boring SWM-1.

Fill materials were described sandy SILT (ML), lean CLAY (CL), and fat CLAY (CH), with varying

amounts of sand and gravel, clayey SAND (SC), silty SAND (SM), clayey GRAVEL (GC), and silty

GRAVEL (GM). Many specimens of the sampled fill appeared to contain a varying amounts of fine

black material that was described as likely cinders. The sampled fill materials were brown, light

brown, dark brown, reddish brown, tan, black, and gray, in color, with a moisture content visually

characterized as moist to wet. The Standard Penetration Test values (N-Values) in the fill ranged

from 4 bpf to 100+ bpf.

4.2.4 Coastal Plain Soils

Alluvial deposited soils of the coastal plain were found to underlie the fill material described above,

and were present until the boring termination depth; expect for as mentioned above in SWM-1.

These naturally occurring deposits were found to consist of sandy Lean CLAY (CL), with varying

amounts of sand, clayey SAND (SC), silty SAND (SM), and poorly graded SAND (SP) soils. Coastal plain

materials were dark brown, light brown, brown, gray and black in color, with moisture contents

visually characterized as very moist to saturated. SPT values in the coastal plain soils ranged from 2

bpf to 13 bpf.

4.3 Subsurface Water

The test borings were monitored during and after drilling operations to obtain short-term

subsurface water information, and again after a 24 hour interval in borings B-5, B-6, B-7, and

SWM-1 through SWM-5. Subsurface water was encountered at depths ranging from 2.5 feet to

9.5 feet below existing site grades. It should be noted that the location of the subsurface water

table could vary by several feet because of seasonal fluctuations in precipitation, evaporation,

surface water runoff, local topography, and other factors not immediately apparent at the time

of this exploration. Normally, the highest subsurface water levels occur in the late winter and

spring and lowest levels occur in the late summer and fall.



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4.4 Laboratory Test Results

As discussed in Section 3.2, laboratory testing was performed on a representative soil samples

collected during our subsurface exploration. The results from the laboratory testing are included

in the following table.

Boring No.

Sample Depth (Feet)

Natural Water

Content (%)

Liquid Limit/

Plasticity Index

% Passing No. 200

Sieve

USCS Class.

Optimum moisture*

(%)

Maximum Dry

Density* (pcf)

Soaked CBR (%)

B-1 2-3.5 6.5 -- -- -- -- -- --

B-1 0-10 6.1 Non-Plastic 54.5 ML 11.9 132.3 --

B-1 0-10 13.6 34/18 51.1 CL 12.9 116.4 1.9

B-2 2.5-4 6.3 -- -- -- -- -- --

B-2 8.5-10 31.9 -- -- -- -- -- --

B-3 2.5-4 10.9 -- -- -- -- -- --

B-3 8.5-10 23.2 -- -- -- -- -- --

B-4 0-10 8.4 25/11 42.9 SC 10.3 126.5 3.8

B-5 8.5-10 13.1 -- -- -- -- -- --

B-6 2.5-4 19.5 -- -- -- -- -- --

B-6 5-6.5 33.1 -- -- -- -- -- --

B-6 8.5-10 24.3 -- -- -- -- -- --

B-7 2.5-4 27.7 -- -- -- -- -- --

B-7 5-6.5 17.8 -- -- -- -- -- --

B-7 8.5-10 22.2 -- -- -- -- -- --

B-8 0-10 13.5 26/10 40.4 SC 9.0 124.4 5.2

SWM-1 2.5-4 18.4 28/9 50.0 CL -- -- --

SWM-2 2.5-4 26.1 Non-plastic 13.5 SM -- -- --



SWM-5 5-6.5 27.2 29/12 83.8 CL -- -- --

*as per the standard Proctor method B (ASTM 698)



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5.0 GEOTECHNICAL DESIGN RECOMMENDATIONS

5.1 General The following evaluations and recommendations are based on our observations at the site,

interpretation of the field data obtained during this exploration and our experience with similar

subsurface conditions and projects. Soil penetration data has been used to estimate an allowable

bearing pressure and associated settlement using established correlations. Subsurface conditions in

unexplored locations may vary from those encountered. If the structure locations, loadings, or

elevations are changed, we should be notified and requested to confirm and, if necessary,

re-evaluate our recommendations.

Determination of an appropriate foundation system for a given structure is dependent on the

proposed structural loads, soil conditions, and construction constraints such as proximity to other

structures, etc. The subsurface exploration aids the geotechnical engineer in determining the soil

stratum appropriate for structural support. This determination includes considerations with regard

to both allowable bearing capacity and compressibility of the soil strata. In addition, since the

method of construction greatly affects the soils intended for structural support, consideration must

be given to the implementation of suitable methods of site preparation, fill compaction, and other

aspects of construction, where applicable.

5.2 Design Recommendations for Foundation Elements We note that existing fill materials were present well below the anticipated foundation bearing

levels for the proposed fuel center support structures. Based on F&R’s soil boring data and site

observation it appears that the existing fill materials may have been placed in a controlled method;

however, records of compaction testing were not provided. We note that that the fill materials

encountered in the borings generally did not include excessive amounts of organics or deleterious

debris; however, the composition of the sampled fill varied significantly and the presence of cinders

was common.

Considering the nature of the proposed structures and the anticipated loads, we envision that the

proposed structures can be supported on a shallow foundation system bearing on approved existing

fill materials, provided that the risks regarding construction on existing fill materials are understood

and accepted. We recommend that foundations be designed for a net allowable bearing pressure

not to exceed 1,500 pounds per square feet (psf).



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To reduce the possibility of localized shear failures, column and strip footings should be a minimum

of 3 feet and 2 feet wide, respectively. We recommend that all exterior footings be placed a

minimum of 2.5 feet below finished exterior grades, which should also be adequate to protect

exterior footings against the effects of frost.

5.3 Supporting on Existing Fill

In order to eliminate the risks associated with structural support on existing fill materials, the

existing materials could be completely removed and replaced with new controlled structural fill, or

deep foundation support could be considered. However, considering the site conditions, we

anticipate that neither complete removal of the fill nor deep foundations will be cost effective for

this project. Furthermore, based on the boring data, and given the relatively light load of the

anticipated structures, it appears that light structural support on the existing fill materials may be

possible provided that the recommended engineering evaluations (as described in Section 6.3 of

this report) are performed and the owner is willing to accept some risk. The risks associated with

structural support on the existing fills in the short term include additional support related cost (i.e.

undercutting, stabilization, etc.) should unforeseen conditions be encountered during construction.

Long-term risk (i.e. excessive settlement) can be reduced by requesting an F&R engineer to perform

the recommended subgrade evaluations during construction.

5.4 Foundation Settlement

Based on the boring data, proposed grading, and assumed structural information, we estimate that

foundation settlements will be less than 1 inch with differential settlement of up to one-half the

estimated total settlement. The magnitude of differential settlements will be influenced by the

variation in excavation requirements across the foundation footprint, the distribution of loads, and

the variability of underlying soils.

Our settlement analysis was performed on the basis of the assumed structural loading and provided

grading information discussed above. Actual settlements experienced by the structure and the time

required for these soils to settle will be influenced by undetected variations in subsurface conditions,

final grading plans, and the quality of fill placement and foundation construction.

5.5 Infiltration Practices

According to the Maryland Stormwater Design Manual requirements, infiltration is only permissible

where infiltration rates exceed 0.52 inches per hour, and groundwater or an impermeable layer is

not located within 2 to 4 feet of the planned bottom of the facility. The infiltration rate can be

determined from field testing and estimated empirically from USDA soil classification.



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Infiltration testing was conducted at locations offset approximately 10 to 20 feet from

corresponding boring locations at the depths of between 2 and 5.5 feet below existing grades.

Inititial infiltration testing was scheduled to be performed at 8 feet below existing grades at all

locations; however, field adjustment were made due to the 24 hour water readings recorded in the

corresponding soil test boring. The results of the infiltration testing, along with the USDA soil

classification and the empirical infiltration rate, are included in the table below:

Infiltration Test Results

Corresponding

Boring No.

24 Hour

Subsurface

Water

Depth

Test Depth

Below Grade

Approx.

Test

Elevation

Infiltration

Test Result

(inches/hr)

Site Average

Rate

(inches/hr)

USDA Soil

Class.

Empirical

Rate

(inches/hr)

SWM-1 5.5ft 3.5ft 13.5 0.24 Loam 0.52

SWM-2 3ft 2ft 17.0 0.36 loamy Sand 2.41

SWM-3 3.5ft 2ft 17.0 0.48 sandy Loam 1.02

SWM-4 7.5ft 5.5ft 13.5 0.60 sandy Loam 1.02

SWM-5 6ft 4ft 11.0 0.60silty clay

Loam0.06

0.46

The field infiltration test rates at SWM-1, SWM-2, and SWM-3, and the overall average infiltration

rate shown above does not meet or exceed the minimum acceptable rate for infiltration. Based

on the foregoing, infiltration practices are not considered feasible at the locations and elevations

tested. We note that only the infiltration rates recorded at SWM-4 and SWM-5 exceeded the

minimum infiltration rate of 0.52 inches per hour; however, it should also be understood that the

infiltration testing is believed to have been performed in existing fill materials. Furthermore, we

note that the field infiltration rates vary slightly from the empirical rates established by USDA

based on soil classifications. It is our opinion that the field test provides a more accurate

representation of the soils infiltration capacity. However, we note that seasonal weather

conditions may also influence the rates recorded in the field. Additionally, we note that

subsurface water levels were found to be relatively shallow and low permeability clayey soils (i.e.

CL, CH, and SC) were commonly encountered in the test borings.

5.6 Concrete Slab and Sidewalk Considerations

Concrete slabs and sidewalks may be designed as a slab-on-grade supported by newly placed

controlled fill, and/or approved existing fill. Any loose/soft or otherwise unsuitable materials

encountered should be remediated by either additional undercuts, with grades restored with

properly compacted acceptable fill materials, or stabilized through other methods as judged

necessary by the Geotechnical Engineer. Considering the extent and varying nature of the onsite

fills, some partial undercutting of the existing fill materials should be expected to stabilize the

subgrades for slab support. For planning purposes we recommend that the slab subgrades be



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undercut at least 12 inches below planned subgrade levels, followed by placement of a woven

geotextile such as Mirafi HP 270 and compacted with a well-graded gravel material such as CR-6

or RC-6. Additional recommendations regarding undercutting for slab support are provided in

Section 6.1 of this report.

We recommend that all slab-on-grades and sidewalks be underlain by 6-inches of well-

compacted granular materials, which should conform to an open graded aggregate (such as No.

57 Stone). This granular material provides a capillary break between the subgrade and slab-on-

grade; while also providing a uniform bearing surface. A vapor retarder should be used beneath

ground floor slabs that will be covered by tile, wood, carpet, impermeable floor coatings, and/or

if other moisture-sensitive equipment or materials will be in contact with the floor. However, the

use of vapor retarders may result in excessive curling of concrete slabs and sidewalks during

curing. We refer the concrete slab and sidewalk designer to ACI 302.1R-96, Sections 4.1.5 and

11.11, for further discussion on vapor retarders, curling, and the means to minimize concrete

shrinkage and curling.

Proper jointing of the ground concrete slab and sidewalk is also essential to minimize cracking.

ACI suggests that unreinforced, plain concrete slabs may be jointed at spacings of 24 to 36 times

the slab thickness, up to a maximum spacing of 18 feet. Slab construction should incorporate

isolation joints along bearing walls and around column locations to allow minor movements to

occur without damage. Utility or other construction excavations in the prepared slab subgrade

should be backfilled to a controlled fill criteria to provide uniform floor support.

Structural analyses and design of floor slab foundation may require the use of a vertical modulus

of subgrade reaction (k). Based on published correlations, we estimate that a design modulus of

subgrade reaction (k) = 100 pci is appropriate for floor slab design calculations, provided that the

recommended 4-inch subbase is utilized. Note that this modulus value should not be confused

with the k value which was provided for the preliminary design of mat foundations in Section 5.4

of this report.

5.7 Pavement Construction

We understand that asphaltic concrete pavement is planned for new at grade parking lots and

driveways on the site. We anticipate that the parking areas will service primarily automobile

traffic, while the driveways will have delivery truck, trailers, and trash truck traffic, along with

automobile traffic. Therefore, two pavement sections have been designed based on different

loading conditions: standard-duty traffic (automobile traffic only) and heavy-duty traffic (tractor

trailer traffic).



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We expect that the proposed pavement areas are also underlain by existing fill materials but we

do not anticipate the need for complete removal and replacement of the existing fill materials.

However, the same settlement risks as described above in Section 5.2, also apply to pavement

support on existing fill. For pavement support, we recommend evaluating pavement subgrades

as described in Section 6.1, Site Preparation, of this report.

CBR testing was completed on three (3) bulk samples taken from borings B-1, B-4, and B-8, at a

depths of 0 to 10 feet below the existing ground surface. The samples were classified as a lean

CLAY (CL), and clayey SAND (SC) according to the USCS and provided soaked CBR values of 1.9,

6.1, and 5.2 at 0.1 inches penetration, respectively. For design, to account for some variability of

the on-site soils, we have chosen to use a CBR value of 3. The CBR value of the actual subgrade

materials used should be verified prior to the construction of any pavements.

The following design values were used for our analysis:

Standard duty traffic loading 10,000 equivalent single axle loads (ESAL) Heavy duty traffic loading 500,000 ESAL Design life 20 years Reliability 85 % Variance 0.45 Initial serviceability 4.2 Terminal serviceability 2.0

Our flexible pavement design analysis was based on methodology from the American Association

of State Highway and Transportation Officials’ (AASHTO) Guide of Design of Pavement Structures,

1993. We have also considered rigid pavements for the heavy duty areas, based on the guidelines

presented in ACI 330R-08. Based on the assumptions and methodologies presented above, we

recommend the following pavement sections:

PAVEMENT SECTION HEAVY STANDARD

LAYER VDOT SPECIFICATION (SUPERPAVE)

THICKNESS (INCHES)

THICKNESS (INCHES)

Surface Course

Asphalt Concrete (SM-9.5A) 3.0 3.0

Intermediate Course

Asphalt Concrete (IM-19) 3.0 ---

Subbase Course

Type I Crushed Aggregate (No. 21A or No. 21B)

12.0 6.0

Our pavement recommendations are based on pavements being supported on soils similar to the

soils we tested. Fill materials underlying pavements should be placed in accordance with the

controlled fill and pavement subgrade recommendations contained in this report. In addition,



Page - 14 -

all pavement subgrades should be evaluated by a geotechnical engineer prior to basestone

placement. If excessive subgrade movement is observed, appropriate improvements such as

undercutting and/or in-place stabilization will be required at that time. For planning purposes, if

unstable subgrades are encountered, extensive undercuts are not anticipated to be feasible due

to the general soft nature of the coastal plain soils, the variation in fill materials, and the relatively

high subsurface water levels. Therefore, we recommend that the contractor be prepared to

overlay pavement subgrades with a reinforcing Geogrid such as a Tensar TriAx, for full 360 degree

radial stiffness, before the placement the subbase stone layer.

It is recommended that the approaches, loading and unloading areas, main turnaround areas and

other areas subjected to excessive starting and stopping motion (such as the dumpster area), be

supported with concrete pavement. For pavements restricted to light duty traffic and where

excessive starting and stopping motions are anticipated, we recommend the pavement be

constructed of 4 inch thick concrete. For pavements subject to heavy duty traffic with excessive

starting and stopping motions, we recommend that the pavement be constructed of 6 inch thick

concrete.

The pavement sections provided above have been developed for conventional post construction

traffic conditions. Since the supportive qualities of these pavement sections for their respective

uses are reliant upon full construction of the subbase, base, and surface courses, partial

construction of either of these sections to facilitate construction traffic may result in subgrade

and pavement failures, due to the inadequate supportive qualities of an incomplete pavement

section and the heavy concentrated loads associated with construction traffic. Excessively heavy,

repetitive construction and/or permanent traffic loads, heavy static loads, and (especially) poor

drainage conditions could cause failures. Specific problem areas, should they occur subsequent

to construction, will have to be remedied on a case by case basis.

5.8 Seismic Considerations

The following Seismic Site Class Definition was established per Section 1613.3.2 of the 2012

International Building Code (IBC) and Chapter 20 of ASCE 7. Our scope of services did not include

a seismic conditions survey to determine site-specific shear wave velocity information. This

method requires averaging N-values over the top 100 feet of the subsurface profile. Based on

our experience in this area and the data from our testing and subsurface exploration and in

general accordance with Section 1613.3.2 of the 2012 International Building Code (IBC) and

Chapter 20 of ASCE 7, a Site Classification “D” should be used for further evaluations relative to

earthquake load design.



Page - 15 -

6.0 GEOTECHNICAL CONSTRUCTION RECOMMENDATIONS

6.1 Site Preparation

Before proceeding with construction, existing structures, utilities, asphalt, concrete and crushed

stone, and other deleterious non-soil materials (if any) should be stripped or removed from the

proposed construction area. Attention should be given to these areas to ensure all unsuitable

material is removed prior to continuing with construction. During the site preparation

operations, positive surface drainage should be maintained to prevent the accumulation of

water. Existing underground utilities should be re-routed to locations a minimum of 10 feet

outside of any proposed structures or abandoned in place with flowable fill.

After stripping, areas intended to support new fill, pavements, and foundations should be

carefully evaluated by a geotechnical engineer. At that time, the engineer may require

proofrolling of the subgrade with a 20- to 30-ton loaded truck or other pneumatic-tired vehicle

of similar size and weight. Proofrolling should be performed during a time of good weather and

not while the site is wet, frozen, or severely desiccated. The purpose of the proofrolling is to

locate soft, weak, or excessively wet soils present at the time of construction. The existing fill

materials may generally be left in place for support of the pavement areas and structures,

provided that they are stable during proofrolling and do not contain excessive amounts of debris

or organics. Any unsuitable materials observed during the evaluation and proofrolling operations

should be undercut and replaced with compacted fill and/or stabilized in-place.

The proofrolling observation is an opportunity for the geotechnical engineer to locate

inconsistencies intermediate of our boring locations and evaluate the stability of the existing

subgrade materials. Any unsuitable materials observed during the evaluation and proofrolling

operations should be undercut and replaced with compacted or flowable fill, or stabilized

in-place. We anticipate the existing fill materials at the project site, like those encountered in

the test borings, will be suitable for support of the proposed lightly loaded support building.

However, we note that the in-situ condition of undocumented fills can vary significantly over

relatively short horizontal distances; therefore, it is imperative that the subgrade materials be

evaluated by the geotechnical engineer as recommended in Section 5.3 of this report. The

possible need for, and extent of, undercutting and/or in-place stabilization required can best be

determined by the geotechnical engineer at the time of construction. Once the site has been

properly prepared, at-grade construction may proceed.



Page - 16 -

6.2 Structural Fill Placement and Compaction Fill materials placed within building/structure footprints should be classified as silty SAND (SM)

or more granular soil, as defined by the Unified Soil Classification System. Fill materials for paved

areas may consist of the non-organic, and uncontaminated, on-site soils, or an off-site borrow

having a classification of SC or more granular. Fill materials should have a maximum liquid limit

(LL) of 45 and plasticity index (PI) less than 20. Other materials may be suitable for use as

controlled fill material and should be individually evaluated by the geotechnical engineer.

Controlled fill should be free of boulders, organic matter, debris, or other deleterious materials

and should have a maximum particle size no greater than 3 inches. In addition, we recommend a

minimum standard Proctor (ASTM D 698) maximum dry density of approximately 95 pounds per

cubic feet for fill materials.

Due to the varying nature of the onsite existing fill soils, we expect that some controlled granular

off-site borrow soils will be needed for the backfilling of any necessary undercuts made within

building pads and/or structure footprints. However, based on our visual classifications and the

laboratory testing, we anticipate that the on-site soils should serve satisfactorily as fill in paved

areas provided that the moisture contents can be maintained within acceptable limits. The on-

site soils are considered moisture sensitive and may be difficult to work with when they are wet

of the optimum moisture content. The laboratory test results indicate that the moisture content

of some of the soil samples were well above their anticipated optimum moisture content,

therefore, some wetting or drying of the on-site soils should be anticipated.

Predicated on the boring and laboratory results, and the recommendations provided above, the

best time for construction of the structural fills and compacted subgrades would be during the

warmer, drier months of the year, such as from late April through early October. During this time

frame, on-site soils that are wet of optimum can usually be dried to near optimum levels with

relatively little effort. If grading is performed during the colder, wetter months of the year, such

as late October through early April, and suitable dry materials are not available on site, then off-

site drier borrow sources will likely be necessary.

Fill materials should be placed in horizontal lifts with a maximum loose lift thickness of 8 inches.

New fill should be adequately keyed into stripped and scarified subgrade soils. The fill should be

compacted to at least 95 percent of the material’s maximum dry density as determined by the

standard Proctor method (ASTM D 698). In confined areas, portable compaction equipment and

thin lifts of 3 to 4 inches may be required to achieve specified degrees of compaction. Each lift

of the fill should be tested in order to confirm that the recommended degree of compaction is



Page - 17 -

attained. Excessively wet or dry soils should not be used as fill materials without proper drying

or wetting. We recommend a moisture content range of plus or minus 3 percentage points of

the material’s optimum moisture content. We recommend that the contractor have equipment

on site during earthwork for both drying and wetting of fill soils.

Where construction traffic or weather has disturbed the subgrade, the upper 8 inches of soils

intended for structural support should be scarified and re-compacted. Field density tests to

determine the degree of compaction should be performed on each lift of fill.

6.3 Foundation Construction All foundation subgrades should be observed, evaluated, and verified for the design bearing

pressure by the geotechnical engineer after excavation and prior to reinforcement steel

placement. It should be understood that the consistency of uncontrolled existing fill can vary

within relatively short horizontal and vertical distances due to the heterogeneous nature their

initial placement. If low consistency soils are encountered during foundation construction,

localized undercutting and/or in-place stabilization of foundation subgrades will be required. The

actual need for, and extent of, undercutting should be based on field observations made by the

geotechnical engineer at the time of construction.

Excavations for footings should be made in such a way as to provide bearing surfaces that are

firm and free of loose, soft, wet, or otherwise disturbed soils. Foundation concrete should not be

placed on frozen or saturated subgrades. If such materials are allowed to remain below

foundations, settlements will increase. Foundation excavations should be concreted as soon as

practical after they are excavated. If an excavation is left open for an extended period, a thin mat

of lean concrete should be placed over the bottom to minimize damage to the bearing surface

from weather or construction activities. Water should not be allowed to pond in any excavation.

Therefore, footings bearing on the clay soils should be completed the day they are excavated or

the bottom of the footing excavation should be covered with a “mud mat” to prevent moisture

change of the clay soils.

6.4 Surface/ Groundwater Control

Subsurface water for the purposes of this report is defined as water encountered below the

existing ground surface. Based on the subsurface water readings obtained during our exploration

program, we do anticipate that subsurface water will likely be encountered during the

anticipated earthwork or shallow foundation excavations, and the contractor should be prepared

to dewater. Fluctuations in subsurface water levels and soil moisture can be anticipated with

changes in precipitation, runoff, and season.



Page - 18 -

An important aspect to consider during development of this site is surface water control. During

the construction, we recommend that steps be taken to enhance surface flow away from any

excavations and promote rapid clearing of rainfall and runoff water following rain events. It

should be incumbent on the contractor to maintain favorable site drainage during construction

to reduce deterioration of otherwise stable subgrades. As mentioned in the site description,

standing water was observed within the drainage swale running the perimeter of the Baltimore

Sun property.

6.5 Temporary Excavation Recommendations

Mass excavations and other excavations required for construction of this project must be

performed in accordance with the United States Department of Labor, Occupational Safety and

Health Administration (OSHA) guidelines (29 CFR 1926, Subpart P, Excavations) or other

applicable jurisdictional codes for permissible temporary side-slope ratios and/or shoring

requirements. The OSHA guidelines require daily inspections of excavations, adjacent areas and

protective systems by a “competent person” for evidence of situations that could result in cave-

ins, indications of failure of a protective system, or other hazardous conditions. All excavated

soils, equipment, building supplies, etc., should be placed away from the edges of the excavation

at a distance equaling or exceeding the depth of the excavation. F&R cautions that the actual

excavation slopes will need to be evaluated frequently each day by the “competent person” and

flatter slopes or the use of shoring may be required to maintain a safe excavation depending

upon excavation specific circumstances. The contractor is responsible for providing the

“competent person” and all aspects of site excavation safety. F&R can evaluate specific

excavation slope situations if we are informed and requested by the owner, designer or

contractor’s “competent person”.



Page - 19 -

7.0 CONTINUATION OF SERVICES

In regards to the continuing work at the site, we recommend that we be given the opportunity to

review the foundation plan, grading plan, and project specifications when construction documents

approach completion. This review evaluates whether the recommendations and comments

provided herein have been understood and properly implemented. We also recommend that

Froehling & Robertson, Inc. be retained for professional and construction materials testing services

during construction of the project. Our continued involvement on the project helps provide

continuity for proper implementation of the recommendations discussed herein.

The Geotechnical Engineer of Record should be retained to monitor and test earthwork activities,

and subgrade preparations for foundations, excavations and floor slabs. It should be noted that the

actual soil conditions at the various subgrade levels and footing bearing grades will vary across this

site and thus the presence of the Geotechnical Engineer and/or his representative during

construction will serve to validate the subsurface conditions and recommendations presented in

this report. We recommend that F&R be employed to monitor the earthwork and foundation

construction, and to report that the recommendations contained in this report are completed in a

satisfactory manner. Our involvement on the project will aid in the proper implementation of the

recommendations discussed herein. The following is a recommended scope of services:

Review of project plans and construction specifications to verify that the recommendations

presented in this report have been properly interpreted and implemented;

Observe and perform testing during earthwork to document that subsurface conditions

encountered during construction are consistent with those anticipated in this report;

Observe subgrade preparation, undercutting of soft/loose unsuitable soils, and fill

placement;

Observe all foundation excavations and footing bearing grades for compliance with the

geotechnical recommendations.



Page - 20 -

8.0 LIMITATIONS

This report has been prepared for the exclusive use of Bohler Engineering or their agent, for specific

application to the Baltimore Sun Consolidation project in accordance with generally accepted soil

and foundation engineering practices. No other warranty, express or implied, is made. Our

evaluations and recommendations are based on design information furnished to us; the data

obtained from the previously described subsurface exploration program, and generally accepted

geotechnical engineering practice. The evaluations and recommendations do not reflect variations

in subsurface conditions which could exist intermediate of the boring locations or in unexplored

areas of the site. Should such variations become apparent during construction, it will be necessary

to re-evaluate our recommendations based upon on-site observations of the conditions.

There are important limitations to this and all geotechnical studies. Some of these limitations are

discussed in the information prepared by GBA, which is included in Appendix III. We ask that you

please review this GBA information.

Regardless of the thoroughness of a subsurface exploration, there is the possibility that conditions

between borings will differ from those at the boring locations, that conditions are not as anticipated

by the designers, or that the construction process has altered the soil conditions. Therefore,

experienced geotechnical engineers should evaluate earthwork, pavement, and foundation

construction to verify that the conditions anticipated in design actually exist. Otherwise, we assume

no responsibility for construction compliance with the design concepts, specifications, or

recommendations.

In the event that changes are made in the design or location of the proposed structure, the

recommendations presented in the report shall not be considered valid unless the changes are

reviewed by our firm and conclusions of this report modified and/or verified in writing. If this report

is copied or transmitted to a third party, it must be copied or transmitted in its entirety, including

text, attachments, and enclosures. Interpretations based on only a part of this report may not be

valid.



APPENDIX I

FROEHLING & ROBERTSON, INC.

Engineering Stability Since 1881

10626 York Road, Suites C-D Cockeysville, Maryland 21030

T 410.825.4131 I F 410.321.7384

Site Location Plan

Client: Bohler Engineering

Project: Baltimore Sun Consolidation


Date: Oct., 2017 Scale: No Scale Drawing No.: 1

SITE

B-1

B-3

B-4

B-5

FR

OEH

LIN

G &

R

OB

ER

TS

ON

, IN

C

Eng

inee

rin

g S

tab

ility

Sin

ce 1

88

1

10

62

6 Y

ork

Ro

ad, S

uit

es C

-D, C

ock

eysv

ille

MD

, 21

03

0

T 4

10

.82

5.4

13

1|

F 4

10

.32

1.7

38

4

Drawing No.

2

B-6

Bo

rin

g Lo

cati

on

Pla

n

Clie

nt:

Bo

hle

r En

gin

eeri

ng

Pro

ject

: Bal

tim

ore

Su

n C

on

solid

atio

n

F&R

Pro

ject

No

.: 7

5V

0084

B-7

Dat

e:

Oct

ob

er, 2

017

Sc

ale

: 1”

= 1

50’

B-2

B-8

SWM-3

SWM-2

SWM-5

SWM-1

SWM-4



APPENDIX II

KEY TO BORING LOG SOIL CLASSIFICATION

Particle Size and Proportion

Verbal descriptions are assigned to each soil sample or stratum based on estimates of the

particle size of each component of the soil and the percentage of each component of the soil.

Particle Size

Descriptive Terms

Proportion

Descriptive Terms

Soil Component Particle Size Component Term Percentage

Boulder

Cobble

Gravel-Coarse

-Fine

Sand-Coarse

-Medium

-Fine

Silt (non-cohesive)

Clay (cohesive)

> 12 inch

3 – 12 inch

¾ - 3 inch

#4 – ¾ inch

#10 - #4

#40 - #10

#200 - #40

< #200

< #200

Major

Secondary

Minor

Uppercase Letters

(e.g., SAND, CLAY)

Adjective

(e.g. sandy, clayey)

Some

Little

Trace

>50%

20%-50%

15%-25%

5%-15%

0%-5%

Notes:

1. Particle size is designated by U.S. Standard Sieve Sizes

2. Because of the small size of the split spoon sampler relative to the size of gravel, the true percentage of gravel may

not be accurately estimated.

Density or Consistency

The standard penetration resistance values (N-values are used to describe the density of

coarse-grained soils (GRAVEL, SAND) or the consistency of fine-grained soils (SILT, CLAY).

Sandy silts of very low plasticity may be assigned a density instead of a consistency.

DENSITY CONSISTENCY

Term N-Value Term N-Value

Very Loose

Loose

Medium-Dense

Dense

Very Dense

0 – 4

5 – 10

11 – 30

31 – 50

> 50

Very Soft

Soft

Medium Stiff

Stiff

Very Stiff

Hard

0 – 1

2 – 4

5 – 8

9 – 15

16 – 30

>30

Notes:

1. The N-value is the number of blows of a 140 lb. hammer freely falling 30 inches required to drive a standard split-

spoon sampler (2.0 in. O.D., 1-3/8 in. I.D.) 12 inches into the soil after properly seating the sampler 6 inches.

2. When encountered, gravel may increase the N-value of the standard penetration test and may not accurately

represent the in-situ density or consistency of the soil sampled.

UNIFIED SOIL CLASSIFICATION SYSTEM (ASTM D-2487)

Major Divisions Group

Symbols Typical Names Laboratory Classification Criteria

Coar

se-g

rain

ed s

oil

s

(Mo

re t

han

hal

f o

f m

ater

ial

is l

arg

er t

han

No

. 20

0 s

ieve

size

)

Gra

vel

s

(Mo

re t

han

hal

f o

f co

arse

fra

ctio

n i

s la

rger

than

No

. 4 s

ieve

size

)

Cle

an g

ravel

s

(lit

tle

or

no

fin

es)

GW Well-graded gravels, gravel-sand mixtures, little or no fines

Det

erm

ine

per

centa

ges

of

san

d a

nd g

rav

el f

rom

gra

in-s

ize

curv

e.

Dep

endin

g o

n

per

centa

ge

of

fines

(fr

acti

on

sm

alle

r th

an N

o. 20

0 S

iev

e),

coar

se-g

rain

ed s

oil

s ar

e

clas

sifi

ed a

s fo

llo

ws:

GW

, G

P,

SW

, S

P

GM

, G

C,

SM

, S

C

Bo

rder

line

case

s re

quir

ing d

ual

sy

mbo

ls Cu=D60/D10 greater than 4;

Cc=(D30)2/(D10x D60) between 1 and 3

GP Poorly graded gravels, gravel-

sand mixtures, little or no fines Not meeting all gradation requirements for GW

Gra

vel

s w

ith f

ines

(Ap

pre

ciab

le

amoun

t o

f fi

nes

)

GM Silty gravels, gravel-sand-silt

mixtures

Atterberg limits below “A”

line or PI less than 4 Above “A” line with PI between 4 and 7 are border-

line cases requiring use of

dual symbols GC

Clayey gravels, gravel-sand-clay

mixtures

Atterberg limits below “A”

line or PI greater than 7

San

ds

(Mo

re t

han

hal

f o

f co

arse

fra

ctio

n i

s

smal

ler

than

No

.4 s

iev

e si

ze)

Cle

an s

and

s

(lit

tle

or

no

fin

es)

SW Well-graded sands, gravelly sands, little or no fines

Les

s th

an 5

per

cen

t

Mo

re t

han

12

per

cen

t

5 t

o 1

2 p

er c

ent

Cu=D60/D10 greater than 6; Cc=(D30)

2/(D10x D60) between 1 and 3

SP Poorly graded sands, gravelly sands, little or no fines

Not meeting all gradation requirements for SW

San

ds

wit

h f

ines

(Ap

pre

ciab

le

amoun

t o

f fi

nes

)

SM Silty sands, sand-silt mixtures Atterberg limits above “A”

line or PI less than 4 Above “A” line with PI between 4 and 7 are border-

line cases requiring use of

dual symbols SC Clayey sands, sand-clay mixtures

Atterberg limits above “A”

line or PI greater than 7

Fin

e-g

rain

ed s

oil

s

(Mo

re t

han

hal

f m

ater

ial

is s

mal

ler

than

No

. 200

sie

ve

Sil

ts a

nd c

lay

s

(Liq

uid

lim

it l

ess

than

50

)

ML

Inorganic silts and very fine

sands, rock flour, silty or clayey fine sands, or clayey silts with

slight plasticity

Pla

sticity Index, P

I

Plasticity Chart

"A" l

ine

Pla

sticity Index, P

I

CL-ML

Pla

sticity Index, P

I

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70 80 90 100

Liquid Limit, LL

CL

CH

ML &

OL

MH & OH

CL Inorganic clays of low to medium plasticity, gravelly clays, sandy

clays, silty clays, lean clays

OL Organic silts and organic silty

clays of low plasticity

Sil

ts a

nd c

lay

s

(Liq

uid

lim

it g

reat

er t

han

50

)

MH

Inorganic silts, micaceous or

diatomaceous fine sandy or silty soils, elastic silts

CH Inorganic clays of high plasticity,

fat clays

OH Organic clays of medium to high plasticity

Hig

hly

org

anic

soil

s

Pt Peat and other highly organic soils

1.5

4.0

6.5

10.0

4-9-9

6-3-1

1-2-3

1-2-2

Surficial Organic SoilBrown, Gray, and Black, Moist, Medium Dense,Silty SAND (SM), Some Gravel, Fine Cinders

FILLBrown, Gray, and Black, Very Moist, Loose,Clayey SAND (SC), Some Gravel, Fine Cinders

FILLLight Brown and Light Gray, Very Moist to Wet,Medium Stiff to Soft, Sandy Lean CLAY (CL)

COASTAL PLAIN SOILS

Boring Terminated at 10 Feet

14.7

12.5

10.0

5.0

0.3

2.5

5.0

10.0

0.0

2.5

5.0

8.5

Subsurface water was notencountered duringdrilling or upon removal ofaugers

18

4

5

4

Elevation: 15 ± Drilling Method: HSAHammer Type: Automatic

F r o e h l in g & R o b e r t s o n , I n c .


City/State: Baltimore, MDProject: Baltimore Sun Consolidation

*Number of blows required for a 140 lb hammer dropping 30" to drive 2" O.D., 1.375" I.D. sampler a total of 18 inches in three 6" increments.The sum of the second and third increments of penetration is termed the standard penetration resistance, N-Value.

Project No: 75V0084Total Depth: 10.0'Boring Location: See Boring Location Plan

BORING LOGBoring: B-1 (1 of 1)

N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R

* SampleBlowsElevation RemarksDescription of Materials

(Classification)

Date Drilled: 10/3/17

BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15-22-48

10-14-40

9-15-8

2-2-4

Surficial Organic SoilLight Brown, Moist, Very Dense, Silty SAND (SM),Trace Gravel

FILLBrown, Reddish Brown, and Black, Very Moist,Very Dense, Silty GRAVEL (GM), Some Sand, FineCinders

FILLBrown, Tan, and Black, Very Moist, MediumDense, Clayey GRAVEL (GC), Some Sand, ShellFragments, Fine Cinders

FILLBrown, Very Moist, Medium Stiff, Sandy LeanCLAY (CL)

COASTAL PLAIN SOILSBoring Terminated at 10 Feet

18.7

16.5

14.0

10.5

9.0

0.3

2.5

5.0

8.5

10.0

0.0

2.5

5.0

8.5


70

54

23

6








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

8-13-15

5-6-9

4-4-3

1-1-3

6 inches of Asphalt underlain by 6 inches ofSubbase GravelBrown, Tan, and Black, Moist, Medium Dense,Silty GRAVEL (GM), Some Sand, Fine Cinders

FILLTan and Black, Moist, Medium Dense, ClayeyGRAVEL (GC), Some Sand, Fine Cinders

FILLBrown, Tan, and Black, Very Moist, Loose, ClayeySAND (SC), Little Gravel, Fine Cinders

FILLLight Brown, Wet, Soft Sandy Lean CLAY (CL)


17.0

15.5

13.0

9.5

8.0

1.0

2.5

5.0

8.5

10.0

0.0

2.5

5.0

8.5


28

15

7

4








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

9.2

15.0

9-16-22

10-14-14

10-18-20

20-50/2

3-2-2

Surficial Organic SoilBrown and Reddish Brown, Moist, Dense, SiltySAND (SM), Some Gravel

FILLTan and Brown, Moist, Medium Dense, ClayeySAND (SC), Trace Gravel

FILLReddish Brown and Gray, Very Moist, Dense, SiltySAND (SM), Some Gravel

FILL

Brown and Gray, Moist, Very Dense, Silty GRAVEL(GM), Some Sand

POSSIBLE FILL

Gray, Wet, Soft, Sandy Lean CLAY (CL)COASTAL PLAIN SOILS


18.7

16.5

14.0

10.5

5.5

4.0

0.3

2.5

5.0

8.5

13.5

15.0

0.0

2.5

5.0

8.5

13.5

Subsurface water wasrecorded at a depth of9.5ft upon removal ofaugers

38

28

38

100+

4








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15.0

8-10-9

8-14-17

21-27-28

15-8-5

1-3-2

Surficial Organic SoilBrown, Reddish Brown, and Black, Moist,Medium Dense to Dense, Silty SAND (SM), SomeGravel, Little Cinders

FILL

Brown and Black, Moist, Very Dense, Silty SAND(SM) and Cinders

FILL

Dark Brown and Gray, Wet, Medium Dense, SiltySAND (SM), Some Gravel

POSSIBLE FILL

Dark Brown and Black, Saturated, Loose, PoorlyGraded SAND (SP)


17.7

13.0

9.5

4.5

3.0

0.3

5.0

8.5

13.5

15.0

0.0

2.5

5.0

8.5

13.5

Subsurface water wasrecorded at a depth of8.5ft upon removal ofaugers. After 24 hours thesubsurface water levelwas recorded at 7ft.

19

31

55

13

5








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

11-9-10

9-9-6

3-2-1

2-3-4

Surficial Organic SoilBrown and Black, Moist, Medium Dense, SiltySAND (SM), Trace Gravel, Trace Cinders

FILLBrown, Very Moist, Medium Dense, Fine SiltySAND (SM)

COASTAL PLAIN SOILSDark Brown, Wet, Soft, Sandy Lean CLAY (CL)

COASTAL PLAIN SOILS

Dark Gray, Wet, Loose, Poorly Graded SAND (SP)COASTAL PLAIN SOILS


17.7

15.5

13.0

9.5

8.0

0.3

2.5

5.0

8.5

10.0

0.0

2.5

5.0

8.5

Subsurface water wasrecorded at a depth of6.5ft upon removal ofaugers. After 24 hours thesubsurface water levelwas recorded at 2.5ft.

19

15

3

7








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

4-9-5

1-1-3

2-4-6

1-1-3

Surficial Organic SoilBrown and Black, Moist, Stiff, Sandy SILT (ML),Trace Gravel, Some Cinders

FILLDark Brown and Black, Moist, Soft, Sandy LeanCLAY (CL), Trace Cinders

FILLDark Gray, Very Moist, Loose, Poorly GradedSAND (SP)

COASTAL PLAIN SOILS

Dark Brown, Very Moist, Soft, Sandy Lean CLAY(CL)


16.7

14.5

12.0

8.5

7.0

0.3

2.5

5.0

8.5

10.0

0.0

2.5

5.0

8.5

Subsurface water was notencountered duringdrilling or upon removal ofaugers. After 24 hours thesubsurface water levelwas recorded at 6ft.

14

4

10

4








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

2-4-10

8-7-7

1-1-1

1-2-2

6 inches of Asphalt underlain by 6 inches ofSubbase GravelReddish Brown, Moist, Stiff, Gravelly Fat CLAY(CH)

FILLLight Brown, Very Moist, Medium Dense, SiltySAND (SM), Some Gravel

FILLDark Brown, Very Moist to Wet, Very Soft to Soft,Sandy Lean CLAY (CL)

COASTAL PLAIN SOILS


19.0

17.5

15.0

10.0

1.0

2.5

5.0

10.0

0.0

2.5

5.0

8.5


14

14

2

4








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15.0

9-21-16

2-3-6

2-5-6

3-3-6

1-3-4

Surficial Organic SoilBrown and Black, Moist, Dense, Silty SAND (SM),Some Gravel, Some Cinders

FILLDark Brown and Black, Very Moist, Stiff, SandyLean CLAY (CL)

FILLBrown, Wet, Medium Dense, Silty SAND (SM)

FILL

Dark Brown, Dark Gray, and Black, Very Moist,Stiff to Medium Stiff, Sandy Lean CLAY (CL)

POSSIBLE FILL


16.7

14.5

12.0

8.5

2.0

0.3

2.5

5.0

8.5

15.0

0.0

2.5

5.0

8.5

13.5


Field infiltration testingwas performed at a depthof 3.5ft and recorded aninfiltration rate of 0.24inches/hour.

37

9

11

9

7







BORING LOGBoring: SWM-1 (1 of 1)

N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15.0

2-4-8

5-5-5

3-3-3

1-1-1

3-2-3

Surficial Organic SoilBrown and Black, Moist, Medium Dense, SiltySAND (SM), Trace Gravel, Trace Cinders

FILLLight Brown, Very Moist to Wet, Medium Dense,Fine Silty SAND (SM)

COASTAL PLAIN SOILSDark Brown, Wet, Medium Stiff to Soft, SandyLean CLAY (CL)

COASTAL PLAIN SOILS

Dark Brown, Wet, Loose, Clayey SAND (SC)COASTAL PLAIN SOILS

18.7

16.5

14.0

5.5

4.0

0.3

2.5

5.0

13.5

15.0

0.0

2.5

5.0

8.5

13.5


Field infiltration testingwas performed at a depthof 2ft and recorded aninfiltration rate of 0.36inches/hour.

12

10

6

2

5








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15.0

3-8-8

3-6-5

3-5-2

3-3-6

4-6-7

Surficial Organic SoilBrown and Gray, Moist, Medium Dense, SiltySAND (SM), Some Gravel

FILLBrown, Very Moist, Medium Dense, Silty SAND(SM)

FILLBrown and Black, Very Moist, Loose, ClayeySAND (SC), Some Cinders

FILL

Brown and Dark Brown, Wet to Saturated, Looseto Medium Dense, Silty SAND (SM)

COASTAL PLAIN SOILS


18.7

16.5

14.0

10.5

4.0

0.3

2.5

5.0

8.5

15.0

0.0

2.5

5.0

8.5

13.5



16

11

7

9

13








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15.0

10-19-20

9-15-6

7-9-12

5-2-11

1-2-2

Surficial Organic SoilBrown, Reddish Brown, and Black, Moist, Denseto Medium Dense, Silty SAND (SM), Some Gravel

FILL

Tan, Very Moist, Medium Dense, Silty SAND(SM), Some Gravel

FILL

Brown and Black, Very Moist, Medium Dense,Silty SAND (SM), Some Cinders

FILL

Dark Gray, Wet, Soft, Sandy Lean CLAY (CL)COASTAL PLAIN SOILS


18.7

14.0

10.5

5.5

4.0

0.3

5.0

8.5

13.5

15.0

0.0

2.5

5.0

8.5

13.5

Subsurface water wasrecorded at a depth of 8ftupon removal of augers.After 24 hours thesubsurface water levelwas recorded at 7.5ft.

Field infiltration testingwas performed at a depthof 5.5ft and recorded aninfiltration rate of 0.6inches/hour.

39

21

21

13

4








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

1.5

4.0

6.5

10.0

15.0

4-8-7

1-1-3

1-1-2

3-5-5

1-2-2

Surficial Organic SoilBrown and Gray, Moist, Medium Dense, SiltySAND (SM), Some Gravel

FILLDark Gray, Very Moist to Wet, Soft, Sandy LeanCLAY (CL)

POSSIBLE FILL

Brown, Saturated, Loose, Silty SAND (SM)COASTAL PLAIN SOILS

Dark Gray, Very Moist, Soft, Sandy Lean CLAY(CL)


14.7

12.5

6.5

1.5

0.0

0.3

2.5

8.5

13.5

15.0

0.0

2.5

5.0

8.5

13.5



15

4

3

10

4








N-Value(blows/ft)

Driller: W. Rodas

SampleDepth(feet)

Depth

R


(Classification)


BORI

NG

_LO

G 7

5V00

87.G

PJ F

&R.

GD

T 1

0/20

/17

Boring No.Sample

Depth

Natural

Moisture % Sand %Silt % Clay USDA Classification

SWM-1 2.5-4ft 18.4 50 35.7 14.3 LOAM




T 410.825.4131 I F 410.321.7384

USDA Textural Triangle




Date: Oct., 2017

Boring No.Sample

Depth

Natural


SWM-2 2.5-4ft 26.1 86.5 8.1 5.4 Loamy SAND




T 410.825.4131 I F 410.321.7384





Date: Oct., 2017

Boring No.Sample

Depth

Natural


SWM-3 2.5-4ft 16.1 79 7.3 13.7 Sandy LOAM




T 410.825.4131 I F 410.321.7384





Date: Oct., 2017

Boring No.Sample

Depth

Natural


SWM-4 8.5-10ft 35.2 68.5 24.5 6.9 Sandy LOAM




T 410.825.4131 I F 410.321.7384





Date: Oct., 2017

Boring No.Sample

Depth

Natural


SWM-5 5-6.5ft 27.2 16.2 52.5 31.3 Silty Clay LOAM




T 410.825.4131 I F 410.321.7384





Date: Oct., 2017



APPENDIX III

Report of Geotechnical Study - Port...

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