geotechnical report sunshine adult day services ardmore...

Sunshine Adult

Day Services

Ardmore,

Oklahoma

Prepared by

EIKON Project #14167

September 2014

GEOTECHNICAL

REPORT

6-30-2014

September 30, 2014

Ms. Melissa Walker

Sunshine Industries, Inc.

Box 1729

Ardmore, Oklahoma 73402

RE: Geotechnical Investigation

EIKON Project #: 14167

Sunshine Adult Day Services

Ardmore, Oklahoma

Dear Ms. Walker:

Submitted here is our geotechnical report for the project referenced above.

This report presents recommendations to guide design and construction. Results of our field and

laboratory investigations are also included.

We thank you for the opportunity to provide you with our professional services. If we can be of

further assistance, please do not hesitate to contact us.

Sincerely,

EIKON

Cody L. Johnson, E.I.T.

Jeff Isbell, P.E.

OK #24177

EIKON Consultant Group 1405 W. Chapman, Sanger, Texas 76266 P 940-458-7503 F 940-458-7417 W eikoncg.com

Engineering Certificate of Authorization #6555 Expires 06-30-15

EIKON

TABLE OF CONTENTS

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

1.1 SUMMARY OF RECOMMENDATIONS ......................................................................................................................................... 1 1.2 FOUNDATION ALTERNATIVES .................................................................................................................................................... 1

2.0 INTRODUCTION .................................................................................................................................................................................. 2

2.1 PROJECT DESCRIPTION ................................................................................................................................................................. 2 2.2 PURPOSE AND SCOPE OF INVESTIGATION ............................................................................................................................... 2

3.0 FIELD INVESTIGATION .................................................................................................................................................................... 2

3.1 SITE GEOLOGY ................................................................................................................................................................................ 2 3.2 SITE CONDITIONS ........................................................................................................................................................................... 3 3.3 SUBSURFACE CONDITIONS .......................................................................................................................................................... 3 3.4 GROUNDWATER ............................................................................................................................................................................. 3 3.5 TREES ................................................................................................................................................................................................ 3

4.0 PREDICTED MOVEMENTS AND DESIGN PARAMETERS ........................................................................................................ 4

4.1 POTENTIAL VERTICAL MOVEMENT .......................................................................................................................................... 4 4.2 SETTLEMENT ................................................................................................................................................................................... 4 4.3 FOUNDATION DESIGN CONSIDERATIONS: TREES & DRAINAGE ......................................................................................... 4 4.4 GENERAL DISCUSSION OF RISKS ................................................................................................................................................ 4

5.0 RECOMMENDATION FOR DRILLED PIERS ................................................................................................................................ 4

5.1 DRILLED PIERS ................................................................................................................................................................................ 4 5.2 DRILLED PIER DESIGN FOR SOIL INDUCED UPLIFT LOADS .................................................................................................. 5 5.3 DRILLED SHAFT CONSTRUCTION CONSIDERATIONS ............................................................................................................ 5

6.0 RECOMMENDATION FOR A STRUCTURALLY SUSPENDED FOUNDATION ...................................................................... 5

6.1 SUSPENDED GRADE BEAMS AND FLOOR SLABS .................................................................................................................... 6

7.0 RECOMMENDATION FOR PERIMETER GRADE BEAMS AND FLOATING SLAB .............................................................. 6

7.1 PERIMETER SUSPENDED GRADE BEAMS .................................................................................................................................. 6 7.2 FLOATING FLOOR SLAB ................................................................................................................................................................ 6

8.0 RECOMMENDATION FOR A FOOTING FOUNDATION ............................................................................................................ 7

8.1 INSTALLATION OF A VERTICAL OR HORIZONTAL BARRIER ............................................................................................... 7

9.0 MODIFICATION OF SOILS ............................................................................................................................................................... 7

10.0 MOISTURE CONTROL PROCEDURES ..................................................................................................................................... 8

11.0 LATERAL PRESSURES ................................................................................................................................................................. 8

11.1 LATERAL SOIL PRESSURE ....................................................................................................................................................... 8 11.2 LATERAL GROUNDWATER PRESSURE ................................................................................................................................. 9 11.3 LATERAL EXPANSIVE SOIL PRESSURE ................................................................................................................................ 9 11.4 SLIDING RESISTANCE .............................................................................................................................................................. 9

12.0 SEISMIC DESIGN VALUES .......................................................................................................................................................... 9

13.0 PAVEMENT RECOMMENDATIONS ........................................................................................................................................ 10

13.1 GENERAL .................................................................................................................................................................................. 10 13.2 BEHAVIOR CHARACTERISTICS OF EXPANSIVE SOILS BENEATH PAVEMENT .......................................................... 10 13.3 SUBGRADE STRENGTH CHARACTERISTICS ..................................................................................................................... 11 13.4 FLEXIBLE PAVEMENT DESIGN AND RECOMMENDATIONS .......................................................................................... 11 13.5 RIGID PAVEMENT DESIGN AND MATERIAL RECOMMENDATIONS ............................................................................. 12 13.6 SUBGRADE PREPARATION RECOMMENDATIONS ........................................................................................................... 13

14.0 LIMITATIONS ............................................................................................................................................................................... 16

APPENDIX A – GENERAL DESCRIPTIONS OF PROCEDURES, RISKS AND FOUNDATION TYPES

APPENDIX B – SUPPORTING DATA AND BORING LOGS

APPENDIX C – MOISTURE CONTROL PROCEDURES

EIKON

Report No. 14167 P a g e 1

GEOTECHNICAL INVESTIGATION

SUNSHINE ADULT DAY SERVICES

ARDMORE, OKLAHOMA

1.0 EXECUTIVE SUMMARY

This project consists of a one story building which is located Park Street SE in Ardmore,

Oklahoma. Currently, the proposed building site is undeveloped and covered with vegetation.

There are several trees scattered throughout the proposed area of development. For this

Geotechnical Investigation, three borings were advanced to twenty five feet deep beneath the

proposed building site. Additionally, three borings were advanced to five feet deep beneath the

proposed paving areas. Samples were recovered at selected intervals.

The Potential Vertical Movement for this site without any soil modification is approximately 1 ½

to 2 ½ inches from current conditions.

The summary of foundation options listed below are for informational purposes only. Refer to

the remainder of the report for more detailed description of each recommendation, design values

and other recommendations.

1.1 SUMMARY OF RECOMMENDATIONS

DRILLED PIERS

Straight shaft piers bearing a minimum of 5 feet into red/gray shale at 22 to 23 feet.

Drilled piers will most likely require casing due to the presence of sand and water.

SOIL MODIFICATION

3 feet of reworked and reconditioned fill plus 12 inches of select fill.

1.2 FOUNDATION ALTERNATIVES

OPTION #1: STRUCTURALLY SUSPENDED FOUNDATION

The distress caused by the estimated potential vertical movement to a structurally

suspended foundation is negligible, because the structure would be isolated from expansive

soil impact. Due to the expansive soils at this site, this is the most appropriate type of

foundation unless the owners wish to minimize the project costs and assume the

increased risks.

OPTION #2: PERIMETER PIERS AND GRADE BEAMS WITH FLOATING

SLAB ON GRADE

One option which is less costly (with higher risk) than the structurally suspended

foundation is to support the exterior walls and all load bearing walls and columns on drilled

piers and grade beams which are isolated from the expansive soils. The interior floor slab

is placed directly on the subgrade and therefore subject to the potential vertical movement.

The subgrade shall be treated according to the soil modification section.

OPTION #3: SHALLOW FOOTING FOUNDATION

Shallow footings may be used to support the wall and column loads with a floating slab on

grade.

EIKON


2.0 INTRODUCTION

2.1 PROJECT DESCRIPTION

This project consists of a one story building which is located Park Street SE in Ardmore,

Oklahoma. Currently, the proposed building site is undeveloped and covered with vegetation.

There are several trees scattered throughout the proposed area of development. For this

Geotechnical Investigation, three borings were advanced to twenty five feet deep beneath the

proposed building site. Additionally, three borings were advanced to five feet deep beneath the

proposed paving areas. Samples were recovered at selected intervals.

2.2 PURPOSE AND SCOPE OF INVESTIGATION

o The purpose and scope of this investigation and report are as follows:

Test the soil by drilling soil borings and testing the soil in the laboratory.

Use engineering principles based on the borings and laboratory tests to predict the bearing

capacity and potential movement of the soil.

Make recommendations for foundation design options based on the predicted soil

properties along with a description of anticipated performance of each foundation option.

Design/Construction assumptions (if these assumptions are not correct, contact this office

for additional recommendations):

i. Maximum loads on piers/footings: 100 kips

ii. Owner wishes to minimize costs and is willing to accept some risks of movement and

distress in order to accomplish minimal costs

iii. Full testing services will be provided for the following operations:

1. Full time pier drilling observation

2. Approval of all fill

3. Density and moisture control of all fill

4. Quality control of all concrete placement

o This report was authorized by Ms. Melissa Walker by signing the EIKON contract on July

25, 2014. The signed contract was received at our office on August 8, 2014.

3.0 FIELD INVESTIGATION

Soil samples were obtained at the site, and the results of the soil sampling and laboratory testing

are presented on the logs of boring in the appendix. A site map shows the number and

approximate location of each boring and is also included in the appendix.

Truck-mounted drilling equipment was used to advance the borings and to obtain samples for

laboratory evaluation. The samples were extruded in the field, logged, sealed, and packaged to

protect them from disturbance and maintain the soil moisture contents until tested.

3.1 SITE GEOLOGY

The site is located in an area underlain by the Vanoss Formation. Named for the town of Vanoss,

the Vanoss Formation is situated on the outcrop in north-central part of Pontotoc Co, OK, Arkoma

basin, and is the basal of 3 formations of the Pontotoc terrane (Group). Currently, there is no type

EIKON


locality designated. It overlies the Ada formation (new) and contact between them is plane

dividing arkosic and nonarkosic materials. It underlies the Hart limestone member of the Stratford

formation of Pontotoc (all new). It consists of alternating sandstones, conglomerates, shales, and a

few thin limestones. All strata are arkosic, some of the sandstones so much so that they might be

taken for true granites. Arkosic material decreases upward, as sandstones become less prominent.

Near center of formation there are several thin limestone beds (not observed north of Canadian

River) that are generally argillaceous, grading into shale; they are light gray and relatively soft

when fresh, but upon weathering become hard and white. Shales are predominant in upper portion,

are light in color and range through shades of green and gray, with occasional red shale. Its

thickness increases southward although exposed portions east of Konawa is only about 250 ft

thick, while near the southwest corner of the quad is about 650 ft thick. Fauna found in the

formation, though mostly composed of species extending into the Permian, is strongly suggestive

of Pennsylvanian age. Fossils include several plant species as well as gastropods, pelecypods, and

brachiopods.

3.2 SITE CONDITIONS

This site slopes approximately 4 to 5 feet across the proposed building area. Currently, the site is

undeveloped and covered with vegetation. There are several trees located throughout the proposed

area of development.

3.3 SUBSURFACE CONDITIONS

Subsurface conditions encountered in the borings, including descriptions of the various strata and

their depths and thickness, are presented on the logs of borings in the appendix. Note that the

depth on all borings refers to the depth from the existing grade or ground surface present at the

time of the investigation. Boundaries between the various soil types are approximate.

The soil encountered in the borings consists of layers of brown sandy clay followed by

intermingled layers of tan/gray sand and gray shaley clay on top of red shale. Please refer to the

appendix for the results of laboratory testing conducted on each sample and a detailed description

of soil strata encountered at each boring location.

3.4 GROUNDWATER

During drilling operations, seepage was encountered at a depth of approximately 13 to 16 feet

beneath existing grades. Groundwater was observed at depths of approximately 12 to 16 feet upon

completion of drilling operations. It is highly likely that the piers will need to be cased due to this

groundwater.

It is very difficult, if not impossible, to predict the magnitude of subsurface water fluctuations

based on very short term observations. Climatic conditions and changes in subsurface soil

conditions will alter the subsurface drainage characteristics.

3.5 TREES

The trees that are currently on the site have caused the onsite soils to dry significantly, and soil

modification is required for slab on grade structures as mentioned in the remainder of this report.

Also, the owner should understand that trees in close proximity to slab on grade foundations may

cause significant distress by causing excessive moisture fluctuation of the soils beneath the

EIKON


foundation. Refer to the moisture control procedures in the appendix of this report for further

recommendations regarding tree locations and/or placement.

4.0 PREDICTED MOVEMENTS AND DESIGN PARAMETERS

4.1 POTENTIAL VERTICAL MOVEMENT

Based on the standard industry methods of predicting movement described in Appendix A and our

experience, the site has approximately 1 ½ to 2 ½ inches of predicted Potential Vertical

Movement (PVM) from current moisture conditions.

4.2 SETTLEMENT

There should be settlement of the existing soils on the order of one half inch or less assuming the

soil is prepared according to the soil preparation or modification section of this report.

4.3 FOUNDATION DESIGN CONSIDERATIONS: TREES & DRAINAGE

As discussed in Appendix C of this report, trees and drainage have a major affect on foundation

performance because these affect the amount of moisture infiltration beneath a foundation. It is

imperative that the owner or builder relay any information to the design engineer regarding new

tree placement, existing trees that will be in close proximity to the foundation, drainage issues such

as use of french drain systems next to the foundation, placement of retaining walls next to the

foundation, or any other issues that may affect the design of the foundation.

4.4 GENERAL DISCUSSION OF RISKS

The most important information that needs to be relayed to the Foundation Design or Structural

Engineer is the amount of distress an Owner is willing to accept. All foundations placed in contact

with the ground on expansive soils have some risk of distress from soil movement. The potential

movement values presented in this report are only a prediction of the potential movement and are

in no way guaranteed. The owner needs to be aware of this prediction and that there are various

levels of risks associated with different soils and foundation types. This report will attempt to

identify the risks in order to aid the owner in selecting an appropriate foundation for their desires

and budget.

5.0 RECOMMENDATION FOR DRILLED PIERS

This report will assume the water table stays at the level present at the time of the boring. If drilled

piers are used and the water table has movement, notify EIKON for additional recommendations.

5.1 DRILLED PIERS

The following pier design is recommended:

Straight shaft piers that penetrate the red/gray shale found at depths between 22 and 23 feet below

existing grades a minimum of 5 feet with the following design parameters:

7,500 psf (pounds per square foot) allowable end bearing

750 psf in perimeter side friction to resist loads discounting the first 2 feet of penetration

750 psf friction resisting uplift after discounting the first 2 feet of penetration

EIKON


Due to the presence of sand and water at this site, casing will most likely be required.

5.2 DRILLED PIER DESIGN FOR SOIL INDUCED UPLIFT LOADS

Drilled piers will be subject to uplift loads as a result of heave in the overlying clays. The

penetration into the bearing material after two feet will provide anchorage to resist the uplift loads

for the straight shaft piers.

The magnitude of the uplift loads varies with the shaft diameter, soil parameters, and the depth of

the active clays acting on the shaft. The uplift pressures can be approximated at this site by

assuming a uniform uplift pressure of 950 psf acting on the shaft perimeter for a depth of 6 feet.

The drilled shafts beneath a structurally suspended foundation should be a minimum diameter of

18 inches with sufficient continuous vertical reinforcing steel (a minimum of 6 bars) of between ¾

and 1% of the cross section area of the shaft extending to the base of the shafts to resist the

computed uplift loads. The structural engineer should design the actual amount of reinforcement

based on the actual uplift loads on the pier less the constant dead load on the pier. Lateral ties

should be used with continuous spirals preferred.

5.3 DRILLED SHAFT CONSTRUCTION CONSIDERATIONS

Concrete used for the shafts should have a slump of 7 to 9 inches. The drilling of the individual

shafts should be excavated in a continuous operation and concrete placed as soon as practical after

completion of the drilling, particularly if groundwater seepage is detected. No hole shall be left

overnight.

If after drilling a pier the pier is backfilled to be redrilled at a later date, the redrilled pier shall

have the required penetration added to the previously drilled depth.

Casing will most likely be required due to the presence of water. When casing is required, the

hole shall be drilled to a slightly larger diameter. No pier shall have concrete placed in it if there is

more than 2 inches of water in the bottom of the hole. Concrete for piers should have a slump

between 7 and 9 inches achieved with the use of a properly designed mix to maintain the

consistency of the concrete without losing strength.

The top of all piers should be formed with sonotube if necessary to prevent the pier to swell or

mushroom in diameter due to the drilling process because no concrete mushrooms around a pier

shall be allowed. Large uplift forces may concentrate at such a mushroom beyond the design

capacity of the pier. Care shall be taken to prevent concrete from penetrating the void space

created by the void boxes. Seal all joints in the boxes and especially between the boxes and the

side of the piers. Trapezoidal void boxes should not be used and no earth formed beams should be

used.

Piers should be no more than 3 inches out of plumb and within 3 inches of correct location.

6.0 RECOMMENDATION FOR A STRUCTURALLY SUSPENDED FOUNDATION

The distress caused by the estimated potential vertical movement to a structurally suspended

foundation is negligible, because the structure would be isolated from expansive soil impact. Due

EIKON


to the expansive soils at this site, this is the most appropriate type of foundation unless the owners

wish to minimize the project costs and assume increased risks.

Refer to the drilled pier section for the design of the drilled piers.

6.1 SUSPENDED GRADE BEAMS AND FLOOR SLABS

The grade beams should be supported by the piers. A minimum void space of 6 inches should be

provided beneath all grade beams and the floor slab. Provisions should be made to provide

drainage from under the building. Structural cardboard forms can be used to provide the required

voids beneath the floor slab and grade beams. If carton forms are used, care should be taken to

assure that the void boxes are not allowed to become wet or crushed prior to or during concrete

placement and finishing operations. Masonite (1/4” thick), placed on top of the carton forms,

could be used to reduce the risk of crushing of the carton forms during concrete placement and

finishing operations. No trenching of grade beams should be allowed, the beams should be formed

on both sides. Trapezoidal void boxes shall not be used and we recommend using side retainers to

retain the soil from infiltrating the void space.

The fill under the void boxes may be any clean soil and only needs to be compacted as required for

the construction loads. The top 2 inches of fill shall be sand or pea gravel for a leveling bed.

7.0 RECOMMENDATION FOR PERIMETER GRADE BEAMS AND FLOATING SLAB

One option which is less costly (with higher risk) than the structurally suspended foundation is to

support the exterior walls and all load bearing walls and columns on drilled piers and grade beams

which are isolated from the expansive soils. The interior floor slab is placed directly on the

subgrade and therefore subject to the potential vertical movement. The subgrade shall be treated

according to the soil modification section.

Refer to the drilled pier section for the design of the drilled piers. Refer to the soil modification

procedure for soil treatment.

7.1 PERIMETER SUSPENDED GRADE BEAMS

The grade beams should be supported by the piers. A minimum void space of 6 inches should be

provided beneath all grade beams. Structural cardboard forms can be used to provide the

required voids beneath the grade beams. If carton forms are used, care should be taken to assure

that the void boxes are not allowed to become wet or crushed prior to or during concrete placement

and finishing operations.

No concrete mushrooms around a pier shall be allowed. Large uplift forces may concentrate at

such a mushroom beyond the design capacity of the pier. No trenching of grade beams should be

allowed, the beams should be formed on both sides. Trapezoidal void boxes shall not be used and

we recommend using side retainers to retain the soil from infiltrating the void space.

7.2 FLOATING FLOOR SLAB

The interior floor slab shall be soil supported and therefore is subject to movements from the

expansive soil. We recommend the subgrade be modified according to the modification of soils

section of this report to reduce the potential movement. The floor slab should be doweled to the

beams at doors to prevent vertical steps at traffic areas. The owner may expect the majority of the

EIKON


movement to occur in the perimeter 4 to 10 feet of the building and any walls bearing on the slab

in the areas of movement will exhibit distress.

8.0 RECOMMENDATION FOR A FOOTING FOUNDATION

If the client is willing to accept the potential risk of distress due to utilizing a slab on grade

foundation placed over soils with expansive potential, the foundation may be supported using

isolated and continuous footings. However, the client should understand that the foundation will

be subject to the potential vertical movement estimates previously mentioned in this report.

Isolated footings may be designed for an end bearing of 2,000 psf and continuous footings for an

end bearing of 2,500 psf. Isolated footings shall have a minimum width of 2 feet and continuous

footings shall have a minimum width of 16 inches with a minimum depth of 24 inches below final

grades. Refer to the soil modification procedure for soil treatment.

All footings shall be excavated and concrete placed in the same day. We recommend a

representative of EIKON observe all footings prior to placing concrete to verify the bearing strata.

Any footings excavated and left overnight must be observed by EIKON and may be subject to

deeper excavation.

8.1 INSTALLATION OF A VERTICAL OR HORIZONTAL BARRIER

In order to reduce the effects of seasonal moisture fluctuations, and subsequent possible soil

movement, it is recommended that a vertical or horizontal barrier be provided around the perimeter

of the foundation. This can be in the form of an independent barrier as described in Appendix C of

this report. It is also possible to use a vertical barrier by taking the outside grade beam of the

foundation to a depth of 4 feet or greater.

9.0 MODIFICATION OF SOILS

If this project is delayed more than six months from the date of this report, we recommend

that the moisture contents of the soils be checked to verify if any additional soil treatment is

necessary.

We recommend that in order to reduce movement potential in the soil to approximately 1 to 1 ½

inches the following building pad preparation be done:

REWORKED SUBGRADE

Strip the site of all vegetation and remove any remaining organic or deleterious material

beneath the building area.

Excavate to a depth of 3 feet below existing grade, stock pile this soil on site. This

excavation shall be level with this depth being the minimum excavation depth. The

excavation should extend 5 feet beyond building lines or 2 feet beyond adjacent sidewalks,

whichever is greater.

Scarify, rework and recompact the upper 12 inches of the exposed subgrade. The soils

should be compacted to at least 93 percent of the maximum density as determined by

ASTM D 698 (Standard Proctor) to at least +3 percentage points of its optimum moisture

content.

Within 24 hours of scarifying and recompacting the excavated subgrade, begin fill

operations to fill to within no higher than 12 inches of the final pad grade using the

EIKON


stockpiled on-site sandy clay soils. The on-site soils should be compacted in 8 inch lifts to

93 percent of the maximum density as determined by ASTM D 698 (Standard Proctor) to at

least +3 percentage points of its optimum moisture content. This may require a lot of effort

to raise the soil moisture content.

Provide a minimum of 12 inches of select fill on top of the re-worked fill. The select fill

shall have a liquid limit less than 35 and a plasticity index between 4 and 12. The select fill

shall be place in maximum 8-inch lifts and compacted to a range between 95 and 100% of

the maximum Standard Proctor density and within 3 percentage points of its optimum

moisture content.

Place a minimum 10 mil vapor retarder beneath all floor slabs that will have coverings such

as tile, carpet, etc.

Each lift shall be tested for moisture content and compaction by a testing laboratory at a

rate of one test per 3,000 square feet with a minimum of 3 tests per lift.

The moisture control measures given at the end of this report should be followed.

10.0 MOISTURE CONTROL PROCEDURES

Refer to the appendix for a description of moisture control procedures and construction techniques

to minimize the Potential Vertical Movement.

11.0 LATERAL PRESSURES

Retaining walls, basement walls, deep grade beams, deepened curbs and similar structures should

be designed to withstand the lateral pressures exerted by the soil, groundwater, construction

surcharge, design surcharge, expansive soil swelling, and vibration. The design of any structure

retaining over 15 feet of soil should be considered beyond the scope of this report and EIKON

should be contacted for further recommendations.

11.1 LATERAL SOIL PRESSURE

Conditions where the structure will be allowed to rotate from lateral pressure, such as at a retaining

wall or basement wall before the upper floor is constructed, should be designed to resist active soil

pressures. Conditions where the structure will be able to resist rotation, such as at a basement

wall after the upper floor is constructed or a deepened curb, should be designed to resist at-rest

soil pressures. We recommend a minimum factor of safety against sliding and overturning of 1.5,

unless the governing building code requires more. However, in providing resistance to sliding and

overturning, we do not recommend that soil be relied upon where it may eventually erode, be

excavated, or even shrink away if expansive clay is present. In the event that the engineer of

record is confident that soil may be relied upon for resistance to lateral loads, the passive soil

pressure should be used.

We recommend that the following equivalent fluid pressures be used in accounting for the lateral

pressure of the soil. These pressures do not include groundwater, surcharges, expansive soil

swelling, or vibration. If the high-side ground surface slopes up at a retaining wall, calculate the

pressure along the vertical plan at the end of the heel

Soil Description Active (pcf) At-Rest (pcf) Passive (pcf)

Unweathered Rock 0 0 400

Gravels (GW, GP, GM, GC) 45 60 150

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Sands (SW, SP, SM, SC) 60 60 150

Inelastic Silts (ML) 60 100 100

Lean Clays (CL) 60 100 100

Fat Clays (CH) 60 100 100

Organic Soil and Elastic Silts (OL, OH, and MH) shall not be used as backfill.

11.2 LATERAL GROUNDWATER PRESSURE

Where it is possible for the groundwater table to move above the base of the foundation, the

equivalent fluid soil pressure used in design should be increased by the following equation:

Soil Pressure x 0.5 + 62.4 pcf = Soil & Water Pressure

To avoid this pressure increase, we recommend that at least 12” of freely draining gravel backfill

be compacted around a perforated drain pipe and up the face of the structure so that water will

drain out of the pipe to a remote outlet. It is acceptable to install weep holes at 48” oc in lieu of

the perforated drain pipe, as long as a mesh screen is installed to prevent the weep from becoming

clogged.

11.3 LATERAL EXPANSIVE SOIL PRESSURE

If expansive clay material is backfilled against a retaining structure, attention should be given to

the effects of subsequent wetting and drying cycles. In addition to active soil pressures, we

recommend that an expansive soil swelling pressure of 300 psf be used at the ground surface for

design. This pressure should be assumed to decrease linearly to 0 psf at a depth of 6 feet. For

retaining structures that are allowed to rotate, deformation from expansive soil movement may be

significant. Due to the highly expansive soil at this site, therefore, we recommend that properly

compacted select fill be installed to the end of the heel, extending upward on a 1:1 slope away

from the retaining structure.

11.4 SLIDING RESISTANCE

A friction factor of 0.60 for unweathered rock, 0.45 for gravels and sands, 0.35 for inelastic silts,

and 0.30 for clays should be used for design against a sliding failure. An allowable adhesion

between concrete footings and clay providing additional resistance against sliding of 250 psf may

be used if the footings bear on clays (CL or CH). If a higher allowable sliding resistance value is

desired and more information is known about the bearing material, contact EIKON for further

recommendations. If necessary, a key may be installed to increase sliding resistance.

12.0 SEISMIC DESIGN VALUES

In order to calculate the seismic forces according to the 2003 International Building Code (IBC) or

American Society of Civil Engineers document ASCE 7-02, it is necessary to determine a Site

Class. Site Classes may be “A” through “F”. In general, a lower letter (“A” being lower than “F”)

corresponds to lower seismic forces that the structure must be designed to resist.

In order to determine the Site Class, it is necessary to either obtain soil data (borings) down to 100

feet or make reasonable assumptions based on the boring logs and general geological information.

In our experience, it is the local standard of care to perform the latter for this type of project. The

former would certainly provide better information but would cost significantly more. As an

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alternate to these two methods of determining the Site Class, additional testing could theoretically

be performed to measure the average shear wave velocity in the top 100 ft. However, measuring

the shear wave velocity is very rare in the North Texas area and could be expensive.

Based on the boring logs and general geologic information, we recommend that Soil Site Class

“C” be used for this site, for this project. There does not appear to be a significant hazard from

slope instability, liquefaction or subsurface rupture due to faulting or lateral spreading that would

occur during earthquake motion. However, if the Seismic Design Category of the building as

determined by the Structural Engineer is D, E, or F, contact EIKON for a more in-depth

assessment of these hazards.

As this recommendation is based on experience and engineering judgement, it is possible that other

engineers may classify the site differently according to their experience and engineering judgment

and be equally justified. If the Structural Engineer of Record would like to discuss how we arrived

at our recommendation, contact EIKON

13.0 PAVEMENT RECOMMENDATIONS

13.1 GENERAL

The pavement designs given in this report are based on limited information and design

assumptions based on project information provided by the client. The pavement designs shown

below are based on the guidelines and recommendations of the American Concrete Pavement

Association (ACPA), The Asphalt Institute, our experience and professional opinion. However,

the Civil Engineer of record or other design professional responsible for pavement design, has the

final responsibility for the pavement design and all associated specifications for the project.

13.2 BEHAVIOR CHARACTERISTICS OF EXPANSIVE SOILS BENEATH

PAVEMENT

Soils for this site are defined as expansive and have the characteristics of changing volume by

swelling up when they absorb moisture and shrinking or going down when they lose moisture.

The moisture content can be stabilized to some degree in these soils by covering them with an

impermeable surface such as pavement areas. However, if moisture were to be introduced by

surface or subsurface water, poor drainage, addition of excessive irrigation after periods of no

moisture, or removed by desiccation from vegetation (especially trees), the soils can swell or

shrink dramatically and cause major damage to any pavement in contact with the soil. The edge of

the pavement and sidewalks are much more subject to these moisture variations, therefore

differential movements under the curbs and pavement edges are the most common type of

problems. As the soil heave upward, the surface of the pavement will separate due to tension

failure and cause a crack in the pavement. This crack will allow moisture to enter the pavement

and be introduced to the subgrade below. The crack will also weaken the pavement section and

can cause accelerated failure of the surface.

The owners should be fully informed that pavements on expansive soil have a higher tendency for

prolonged maintenance over the life of the pavement, or areas which will fail in a short period of

time. If the owner would like to minimize the effects of expansive soil on pavement areas, the

following level of maintenance and subgrade preparation beneath the pavement can greatly

improve the long term performance by providing the following:

An elevated pavement which provides maximum drainage away from the pavement (a

minimum of 5% slope for the first 5 and preferably 10 feet away from the pavement)

EIKON


Stabilized sub base to extend at least one and preferably two feet past the back of the curbs

or edge of the pavement

Avoid long areas of low slope roadway. Adjust slopes to account for the Potential Vertical

Movement.

Provide proper slope of sidewalks away from the building, to account for the PVM

discussed above.

Providing reconditioned soils beneath the pavement. If the owner desires to review options

for soil treatment to reduce the PVM of the site, this office should be contacted for further

recommendations.

13.3 SUBGRADE STRENGTH CHARACTERISTICS

Based on the testing completed on site, it is recommended that a California Bearing Ratio (CBR)

value of 3 was used in the design and a corresponding resilient modulus of 4,500 psi. Also, a

Modulus of Subgrade Reaction (k) of 150 pci is recommended. These are the design assumption

after anticipated soil preparation.

13.4 FLEXIBLE PAVEMENT DESIGN AND RECOMMENDATIONS

The hot mixed asphaltic concrete (HMAC) for this project should conform to current Oklahoma

DOT standards. The following is recommended for HMAC:

13.4.1 FULL DEPTH HMAC

The full-depth HMAC should consist of 2 inches of Type C or D surface course over 3

inches of Type B base course as specified by Oklahoma DOT. The full depth asphalt

should be placed over 8 inches of Portland Cement or Cement Kiln Dust (CKD) stabilized

subgrade per the recommendations below. HMAC should be installed per the

recommendations below

13.4.2 HMAC INSTALLATION AND TESTING REQUIREMENTS

The following is recommended for HMAC:

- Surface Course to be Oklahoma DOT, Type C or D

- Asphaltic Base Course to be Oklahoma DOT, Type B

- Asphalt shall be placed and compacted to contain from 5 to 9% air voids.

- The target density for asphalt lifts should be 91 to 95% of Maximum

Theoretical Specific Gravity as determined by laboratory testing

- The following tests should be run on each day’s operation:

In place field density tests to establish rolling pattern

One extraction and gradation test

One laboratory density and stability test

Two cores to verify thickness & density

13.4.3 CRUSHED LIMESTONE BASE

- Crushed Limestone Base to be Oklahoma DOT Type A, grade 2 or better. The

material shall be compacted in maximum lifts of 6 inches to at least 98% of

ASTM D 1557 (Modified Proctor) within +/-3 percentage points of optimum.

EIKON


13.5 RIGID PAVEMENT DESIGN AND MATERIAL RECOMMENDATIONS

The typical types of rigid pavement for this type of project are as follows:

1. Continuously Reinforced Concrete Pavement (CRCP):

i. This is the best type of pavement with lowest maintenance

ii. Heavily reinforced to control cracking

iii. Recommended for higher volume traffic areas

2. Jointed Reinforced Concrete Pavement (JRCP):

i. This is the most common type of pavement in the Southern Oklahoma

Area.

ii. Reinforced for temperature and shrinkage and for resistance due to

expansive soil movement

iii. Joint placement and sawcut placement is critical for performance

iv. Generally used for low volume roadways and parking lots

3. Jointed Plain Concrete:

i. Basic unreinforced pavement, and is not recommended for roadways and

parking lots in this area due to expansive soil.

It is assumed that the client desires JRCP pavement, and therefore the recommendations below

refer to that type of pavement.

13.5.1 RIGID PAVEMENT

It is recommended for this site that the Rigid Portland Cement Concrete for this site have a

minimum thickness of 6 inches for all fire lanes, truck traffic lanes, and dumpster pads. A

minimum thickness of 5 inches is recommended for automobile parking. The following

mix design recommendations are as follows:

- Recommended minimum design compressive strength: 3,500 psi

- Recommended minimum design tensile strength: 525 psi

- Well graded optimized aggregate meeting ASTM C-33 with nominal aggregate

size no greater than one and one half (1 ½”) inch

- Portland Cement limited to between 520 and 600 lbs per cubic yard.

- 4 to 6% Air Content using Air Entraining Agent

- 15 to 20% flyash may be used at the approval of the Civil Engineer of record

- Curing compound should be used and placed within one hour of finishing

operations

13.5.2 PAVEMENT REINFORCING STEEL

It is recommended that a minimum of 0.2% of steel be used for the concrete, with a

minimum of #4’s @ 18” on center for 6 inch concrete pavement. Reinforcement chairs

should be used beneath all pavement such that the reinforcement is placed one-third (T/3)

of the pavement thickness from the top of the pavement using metal or plastic chairs with

sand cushions and not brick batts.

13.5.3 PAVEMENT JOINTS AND CUTTING

One of the most imperative parts of the design, construction, and long term maintenance of

a rigid pavement are the joints, either construction joints or sawcut contraction joints. The

Civil Engineer of record, or whoever is responsible for the pavement design, should give

EIKON


adequate attention to construction joint spacing. The following is recommended for joints

and saw cutting:

- Contraction joints (sawcuts) shall have a maximum spacing each way of 30

times the thickness with a maximum spacing of 15 feet, with a maximum of 12

feet preferred.

- Sawcuts should be completed prior to the concrete temperature decreasing by 10

degrees, which is typically a few hours after placement of concrete preferably a

maximum of 5 to 10 hours after placement

- Expansion joints shall be smooth dowel joints, or dowel baskets, with the

pavement thickness increased 25%. If smooth dowel joints are use, one end of

dowels to be greased and capped and use 1” expansion joint material in the

joint. Redwood or other rigid material should not be used.

- Space expansion joints between 80 and 100 feet apart and at locations in which

large pavement sections intersect smaller sections.

- Construction/Expansion Joints should be cleaned and sealed within 48 hours of

concrete placement to avoid infiltration of water, sediment, etc. from entering

the joint

- Avoid long rectangular pours, or pours in which the configuration has “L” or

“T” shape causing the pour to be anchored

13.5.4 SUBGRADE STABILIZATION BENEATH CONCRETE PAVEMENT

Subgrade stabilization is not required beneath rigid concrete pavement.

13.6 SUBGRADE PREPARATION RECOMMENDATIONS

For the subgrade preparation beneath pavement, the following is recommended:

13.6.1 SOIL PREPARATION UNDER PAVEMENT (NO STABILIZATION)

- Remove all vegetation, organic material or other deleterious materials.

- Perform any cut operations as needed and proof roll the pavement areas with a

fully loaded tandem axle dump truck. Any areas which rut excessively or pump

shall be undercut and replaced with compacted fill.

- Perform all fill operations. All fill shall be installed in maximum 8 inch lifts

and compacted to between 95 and 100% of Standard Proctor at a moisture

content at or above optimum.

- Do not use any sand as fill under the pavement. Any imported fill shall be

similar to the on-site soils and approved by EIKON.

- The following tests shall be run per 5000 square feet or 300 linear feet:

Density and moisture control

13.6.2 SOIL PREPARATION UNDER PAVEMENT UTILIZING CEMENT

STABILIZATION





EIKON







- Cement stabilized subgrade shall have a minimum of 28 pounds per square yard

of Portland Cement or Class C Flyash by dry weight measure to be mixed with

the existing soil after scarifying to a depth of at least 8 inches. The soil-cement

mixture shall have a particle distribution of 100% passing a 2” sieve and 80%

passing a No. 4 sieve.

- The cement stabilized subgrade shall extend a minimum of one foot and

preferably two feet past the back of the roadway curbs or edge of asphalt.

- The soil-cement mixture shall be compacted to a minimum of 98% of Standard

Proctor at a moisture content to within +/- 5 percentage points of optimum

moisture.

- Within 12 to 24 hours of final compaction, the cement stabilized subgrade shall

be tested for moisture content and compaction by a testing laboratory.

- Immediately after final moisture and compaction testing, the subgrade shall be

covered with a moisture barrier (ie, prime coat, chip seal, poly, etc.) until the

surface course can be placed. The compacted stabilized base should never be

allowed to dry completely.

- The following tests shall be run per 5000 square feet or 300 linear feet:

Gradation of soil-cement mixture

Density and moisture control

13.6.2.1 CONTROL MEASURES FOR REFLECTIVE CRACKING IN

CEMENT STABILIZED SUBGRADE

The Civil Engineer of Record should take special consideration in addressing the

possibility of shrinkage cracks in cement stabilized subgrade and the subsequent

possibility of reflective cracking of flexible pavement. Based upon information

provided by the Portland Cement Association (PCA) and our experience and

professional opinion, the following information provides many factors contributing

to the cracking of cement treated subgrade along with several procedures to

minimize shrinkage and reflective cracking.

Several factors contribute to the cracking and crack spacing in cement stabilized

subgrade including soil characteristics, soil type, cement content, nature of

compaction and curing, along with environmental influences including temperature

and moisture. All of the aforementioned factors can directly affect the degree of

shrinkage observed in the cement stabilized subgrade, which can also create

cracking in asphalt pavement.

There are multiple preventative measures and design concepts that can be utilized to

minimize shrinkage cracking in the cement stabilized subgrade as well as reduce the

possibility for reflective cracking in flexible pavement from the subgrade, through

the flexible pavement such as the following:

- Provide proper construction techniques including accomplishing the

stabilization process within a reasonable time frame to ensure that the cement

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does not hydrate before final compaction (typically within two hours of cement

mixing)

- Compact the cement treated subgrade at or slightly less than the optimum

moisture content, as determined by ASTM D 698 (opt. to minus 2%). Too

much water in the cement stabilized subgrade may create the potential for

excessive drying, which may lead to wide shrinkage cracks.

- Delay paving as long practical following the placement of the prime coat on

top of the cement stabilized subgrade. The longer the period of time you can

wait after the cement treated subgrade has been properly installed, the greater

the opportunity shrinkage (shrinkage cracks) has to occur, which can result in

fewer and/or thinner cracks in the asphalt. It should be noted that the cement

stabilized subgrade should not be allowed to “dry out”, and a prime coat or

acceptable moisture barrier should be placed within 24 hours of final grading.

- Pre-crack the pavement. A common method to reduce reflective cracking is

through micro cracking. This is completed by utilizing a vibratory roller, 1-2

days after final compaction of the cement treated subgrade, to create a network

of closely spaced hairline cracks in the cement treated subgrade. The hairline

cracks will act to minimize the development of wide shrinkage cracks, while

still allowing time for the micro cracks to heal as the cement treated subgrade

continues to cure and gain strength with time.

- Provide a stress relief layer in the pavement section. An alternative method

to alleviate reflective cracking in flexible pavement is to place a flexible

material between the cement treated subgrade and the surface layers. This can

be accomplished by placing a bituminous surface treatment (chip seal) between

the stabilized subgrade and the surface course; utilizing a geotextile fabric

between the stabilized sugrade and surface course or placing the fabric between

the asphalt binder and the surface courses; or lastly, placing a 2 to 4 inch layer

of unbound granular material between the stabilized subgrade and the asphalt

surface; however, care should be taken to allow for proper drainage within this

layer.

13.6.3 SOIL PREPARATION UNDER PAVEMENT UTILIZING CEMENT KILN

DUST (CKD) STABILIZATION










- CKD stabilized subgrade with a minimum of 10 to 14% cement kiln dust by dry

weight measure to be mixed with the existing soil after scarifying to a depth of

at least 8 inches.

- The soil-CKD mixture shall be compacted to between 98 and 102% of Standard

Proctor at a moisture content to within +/- 5 percentage points of optimum

moisture.

- The CKD stabilized subgrade shall extend a minimum of one foot and

preferably two feet past the back of the roadway curbs or edge of asphalt.

EIKON


- The following tests should be run per 5000 square feet or 300 linear feet:

Density and Moisture control

14.0 LIMITATIONS

The professional services, which have been performed, the findings obtained, and the

recommendations prepared were accomplished in accordance with currently accepted geotechnical

engineering principles and practices. The possibility always exists that the subsurface conditions

at the site may vary from those encountered in the boreholes. The number and spacing of the test

borings were chosen in such a manner as to decrease the possibility of abnormalities, while

considering the nature of loading, size, and the cost of the project. If there are any unusual

conditions differing significantly from those described herein, EIKON should be notified to review

the effects on the performance of the recommended foundation system.

Recommendations contained herein are not considered applicable for an extended period after the

completion date of this report. It is recommended our office be contacted for a review of the

contents of this report for construction commencing more than one year after completion of this

report.

The scope of services provided herein does not include an environmental assessment of the site or

investigation for the presence or absence of hazardous materials in the soil, surface water, or

groundwater.

All contractors referring to this geotechnical report should draw their own conclusions regarding

excavations, trafficability, etc. for bidding purposes. EIKON is not responsible for conclusions,

opinions or recommendations made by others based on these data. The report is intended to guide

preparation of project specifications and should not be used as a substitute for the project

specifications.

Recommendations provided in this report are based on our understanding of information provided

by the Client about characteristics of the project. If the Client notes any deviation from the facts

about characteristics of the project, our office should be contacted immediately since this may

materially alter the recommendations.

EIKON


APPENDIX A

GENERAL DESCRIPTIONS OF

PROCEDURES, RISKS AND

FOUNDATION TYPES

EIKON


LABORATORY INVESTIGATION

Laboratory tests were performed on the soil samples and are presented in the appendix of this

report. The following is a general description of each test. Not all tests are run on each sample or

project. It is up to the engineer to determine which tests to run after observation of the samples.

It is very difficult to predict soil movement and it is one of the most complicated subjects in

engineering. Many different methods, theories, and procedures have been used to various degrees.

The laboratory tests are tools which are used to predict the movement of soils. The more tests run,

the more information the Geotechnical Engineer will have in helping predict the movement. The

discussion below does not include all of the methods used. The most valuable tool is the

experience and judgment of the Engineer.

SOIL SUCTION

Suction is a measure of the ability of a soil to attract moisture or lose moisture. All soil if given

time and a source of moisture or a means to lose moisture will eventually come to equilibrium. If

a soil is at its suction equilibrium and stays at that point, it will not change in volume as long as the

load on the soil does not change. A series of suction measurements versus depth performed on a

soil sample, known as a suction profile, may give the engineer an estimate of that particular soil’s

equilibrium suction and the depth which that constant suction is reached. With this information,

the engineer may be able to predict the movement potential with an assumed surface suction. In

other words, the prediction is very dependent upon how the area around the building is maintained,

what type of drainage patterns and vegetation are present; all things which the engineer cannot

control. These practices are described in the Moisture Control Procedures section of this report.

SWELL TESTS

Swell tests are performed on samples obtained when the borings were drilled. A small (3/4 inch

high) portion of soil is submerged in water while being confined on its sides and bottom. This

confinement simulates the confinement that the soil would experience under in-situ conditions.

The change in height is measured over a period of time until the “swelling” is negligible. This

change in height gives the engineer an estimate of how much the soil will move vertically when

water is introduced to the sample. This method can be very accurate in predicting the movement

but has its caveats. Values that are too high may be predicted if the soil is very dense. On the other

hand, values that are too low may be predicted if the soil was very wet at the time of sampling.

MOISTURE CONTENT

By studying the moisture content of the soils at varying depths and comparing them with the

Atterberg Limits, the Engineer can assume a depth of no further moisture change due to seasonal

variations. Moisture content also aids in the prediction of movement potential in the soil. This is a

good method to predict movements, but is dependent on the moisture contents staying constant

from the time of sampling to the time of construction. Therefore, the Engineer should assume that

the surface soils will dry out some if construction is delayed.

UNCONFINED COMPRESSION

In clay soils, there is a relationship between the strength of the soil and the potential future

movement. If the clay soil is very dry, it will be hard and have a high compressive strength. On

the other hand, if the clay soil is very wet, it will be very soft and have a low compressive strength.

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In sandy clay soils, especially those which are very dense or cemented, this relationship is more

difficult to determine and therefore it is more difficult to predict movement.

Unconfined compression is measured in two ways: with a pocket penetrometer (hand held device)

on the soil samples and in a compression machine in the laboratory. The machine method is more

accurate than the approximate pocket penetrometer method. Unconfined compression is also used

to determine the bearing capacity of footings, beams and piers.

ATTERBERG LIMITS

Atterberg limits give the liquid limit (LL), plastic limit (PL), and plasticity index (PI) of a soil. In

basic terms, the liquid limit is the moisture content of the soil when it becomes liquid (mud). The

plastic limit is the moisture content of the soil when it becomes workable like putty. The PI is the

difference between the liquid limit and the plastic limit.

The PI is a very common but very general classification of the soil. In general, a soil with a PI

below 15 is considered stable and should not move with a change in moisture content, (see

exception below). A soil with a PI above 30 is considered highly active and will exhibit

considerable movement with changes in moisture content. A soil with a PI between 15 and 30 is

considered moderate and more difficult to predict movement.

Fat clays with high liquid limits and cemented sandy or silty clays are examples of soils in which it

can be difficult to predict movement. In such cases, the general classification of plasticity index

may not apply.

GENERAL DISCUSSION OF ANALYTICAL METHODS TO PREDICT MOVEMENT

Once the characteristics of the soil are determined through laboratory tests as discussed in the

above section, the engineer uses this information to predict the potential movement of the soils.

There are several methods which are discussed in general below.

TEXAS DEPARTMENT OF TRANSPORTATION METHOD 124-E

The Texas Department of Transportation (TxDOT) has developed a method to predict movements

for highways based on the plasticity index of the soil. However, this method generally assumes a

dry condition for all soils and can be inaccurate for building foundations. This is a very common

method for engineers to use because of its simplicity. In our opinion, this value can be calculated

for a site but should not be used alone in determination of potential movement.

SUCTION

Suction measurements may be used along with unsaturated soil mechanics principles as published

by various authors to predict soil movement.

SWELL TESTS

Swell tests are very good indicators for potential movement. In our opinion, a weighted swell

value putting more emphasis on the swell characteristics closer to the surface and less on values

deeper down is a reasonable approach to estimating movement.

WIRE REINFORCEMENT INSTITUTE

EIKON


The Wire Reinforcement Institute (WRI) has developed a design methodology using a weighted

plasticity index. This index is modified for ground slope and the strength of the soil. These values

are also used as input into the movement potential.

GENERAL DISCUSSION OF MOVEMENT POTENTIAL

On each site, the above soil tests and analytical methods are used to determine a potential

movement of the soil. In our office, the engineer views the soil samples and determines which soil

tests to perform on the samples. Not all tests are necessary if by inspection the engineer can

predict the characteristics of the soil. Then, all or some of the above analytical methods are used

to determine the theoretical movement of the soil. After all this is accomplished, the engineer

reviews the boring logs, views the samples, studies the test results, uses the test results to calculate

a theoretical movement, and uses his/her experience to estimate the predicted movement value and

edge distances.

The most common causes of movement of soils under slab on grade foundations are drainage and

the influence of trees. Refer to the moisture control procedures in this report for suggested

methods to reduce the movement due to these causes. Any trees to be removed under the new

foundation shall have the entire root ball excavated and replaced with properly compacted fill as

noted in the soil preparation discussion of this report.

A floor slab with movements as much as 1/4 of an inch can cause damage to interior walls. In

other words, the sheet rock or masonry walls may crack and the floor tile may separate. However,

these cracks are usually minor and most people consider them 'liveable'. A movement of one inch

can cause considerable damage and can be quite an eyesore. This is only a potential and has a

moderate probability of occurring, but the risk is there unless a structurally suspended foundation

is used.

The owner needs to be aware of this risk and that if this movement does occur, damage will ensue

and will be visible. This damage will most likely be non-structural in that it will not affect the

structural integrity of the building only the visual integrity. However, if the moisture under the

building is not allowed to change, very little movement will occur. Therefore, proper disposal of

down spout runoff, good drainage, and pavement next to the building will all help to reduce the

probability of movement occurring.

POTENTIAL VERTICAL RISE OR MOVEMENT (PVR OR PVM)

A general index for movement is known as the Potential Vertical Rise (PVR). The actual term

PVR refers to the TxDOT Method 124-E mentioned above but for the purpose of this report will

be used interchangeably with Potential Vertical Movement (PVM) because the term PVM can

indicate any movement. This is an industry wide parameter which is used to represent the

predicted movement of expansive soils. It is generally considered to be a measurement of the

change in height of a foundation from the elevation it was originally placed. Experience and

generally accepted practice suggests that if the PVM of a site is less than one inch, the associated

differential movement will be minor and acceptable to most people.

EIKON


GRAPHIC DESCRIPTION OF VERTICAL MOVEMENT IN A FLOATING FLOOR

SLAB WITH PERIMETER PIERS

SETTLEMENT

Settlement is a measure of a downward movement due to consolidation of soil. This can be from

improperly placed fill, loose native soil, or from large amounts of sandy material. Even properly

compacted fill may settle approximately 1 percent of its depth.

EDGE AND CENTER LIFT MOVEMENT (ym)

The Post-Tensioning Institute (PTI) has developed a parameter of movement defined as the

differential movement (ym) estimated using the change in soil surface elevation in two locations

separated by a distance em within which the differential movement will occur; em being measured

from the exterior of a building to some distance toward the interior. All calculations for this report

are based on the modified PTI procedure in addition to our judgment as necessary for specific site

conditions. The minimum movements given in the PTI are for climatic conditions only and have

been modified somewhat to account for site conditions which may increase the actual parameters.

EIKON


“Center lift” occurs when the center, or some portion of the center of the building, is higher than

the exterior. This can occur when the soil around the exterior shrinks, or the soil under the center

of the building swells, or a combination of both occurs.

“Edge lift” occurs when the edge, or some portion of the exterior of the building, is higher than the

center. This can occur when the soil around the exterior swells. It is not uncommon to have both

the center lift and the edge lift phenomena occurring on the same building, in different areas.

GENERAL DISCUSSION OF FOUNDATION TYPES

Many factors influence the movement of soils (either shrinkage or swell) including the presence of

trees which may be planted at a later time, drainage around the building, and water leaks under the

building. It should be recognized that if the clay soils are allowed to dry excessively prior to

construction, the surficial clays may become highly expansive.

There are several alternatives available to manage the detrimental effects of these movements:

Isolate the foundation from the expansive soils by constructing a structurally suspended slab or

wooden floor over a crawl space.

Attempting to stabilize the soil to reduce the potential from movement.

Where sites are prepared to reduce calculated potential vertical movement (PVM) values to one

inch or less and substructures are designed to tolerate differential movements of this magnitude,

observed distress is generally reduced to a tolerable level as defined by most people.

Based on the potential for movement in the soil and the interaction with the foundation of the

building, the following are our recommended alternative foundation types:

EIKON


Structural Suspended Foundation

Perimeter piers and grade beams with floating slab

Continuous shallow footings

A structurally suspended foundation system consists of a concrete slab or wood floor suspended

above the expansive soils and supported by drilled piers. The superstructure is elevated above the

expansive soils and thus not affected by soil movement.

A foundation with perimeter piers and grade beams and a floating slab will isolate the perimeter of

the building from the detrimental effects of heaving soils but the interior of the building is subject

to the potential movement, normally heave, of the soils. In other words, the exterior brick or other

siding materials will not show distress with this alternative, but might with the stiffened slab

alternative.

A footing foundation consists of spread footings under the exterior walls and load bearing

elements of the foundation. However, this type of foundation offers very little resistance to

expansive soils. Any movement in the soils will most likely be transferred to the foundation.

If a floating slab is used, we recommend that the slab be placed on reworked moisture conditioned

sub-grade soils or the slab be constructed with sufficient stiffness to minimize the deflection and

effects of the differential movement.

Recommendations for the foundation systems are presented in the following report sections.

SPECIAL COMMENTARY ON CONCRETE

RESTRAINT TO SHRINKAGE CRACKS

Concrete is a complicated material with somewhat difficult to predict properties. One of the

characteristics of concrete is that during the curing process shrinkage occurs and if there are any

restraints to prevent the concrete from shrinking, cracks can form. In a typical slab on grade or

structurally suspended foundation there will be cracks due to interior beams and piers that restrict

shrinkage. This restriction is called Restraint to Shrinkage (RTS). In post tensioned slabs, the post

tensioning strands are slack when installed and must be stressed at a later time. The best procedure

is to stress the cables approximately 30% within one to two days of placing the concrete. Then the

cables are stressed fully when the concrete reaches greater strength, usually in 7 days. During this

time before the cables are stressed fully, the concrete may crack more than conventionally

reinforced slabs. When the cables are stressed, some of the cracks will pull together. These RTS

cracks do not normally adversely affect the overall performance of the foundation. However, if

any exposed floors, especially ones which will be painted or stained exist in the building, these

cracks may not be acceptable to the owner and this should be taken into account when deciding to

have exposed concrete floors. Sawcuts and stamped concrete are also not good practices to use on

slab on grade or structural foundations. Any tile which is applied directly to concrete or over a

mortar bed over concrete has a high probability of minor cracks occurring in the tile due to RTS.

It is recommended if tile is used to install expansion joints in appropriate locations to minimize

these cracks.

EIKON


CONCRETE CONSTRUCTION QUALITY

The construction industry, especially the concrete industry, is not a perfect industry. The concrete

industry involves large projects with many variables which may or may not be in the control of the

builder or engineer. Several of these situations include:

Surface cracking due to high winds or high temperatures of the concrete

Honey combing (not completely filled in) of the concrete on the form sides or under brick

ledges

Cracking at the corners due to differential expansion between concrete and brick.

Out of level floors: The American Concrete Institute has a standard of +/- ¾” which gives

an overall of 1 ½” out of level. There can also be as much as ¼” out of level over 10

feet.

If the owner desires to minimize any of the RTS cracks or quality factors, he/she should notify the

engineer and builder of that desire. He/she should recognize that most measures to minimize these

problems increase the cost of the foundation.

SITE GRADING AND EXCAVATIONS

SITE GRADING AND LANDSCAPING

We recommend that the grades around the building be sloped to drain water away from the

building. Site grading plans should include provisions for the effects of soil movements on access

and entry slabs and adjacent sidewalks. Sidewalks should be sloped down from the edge of the

building. The slab should be sloped 5 percent for 8 feet or steeper slope. Storm drain down spouts

should direct water away from the building slab. Trees should not be planted within a distance

equal to the mature tree’s height of the structure to help prevent floor slab settlements caused by

ground shrinkage associated with moisture absorption of the root systems. Care should be taken to

provide for proper slopes for accessibility standards.

UTILITY TRENCH EXCAVATION

Trench excavation for utilities should be sloped or braced in the interest of safety. Attention is

drawn to OSHA Safety and Health Standards (29 CFR 1926/1910), Subpart P, regarding trench

excavations greater than 5 feet in depth.

FIELD SUPERVISION AND DENSITY TESTING

Field density and moisture content determinations should be made on each lift of fill with a

minimum of 3 tests per lift in the building pad area, 1 test per lift per 3,000 sf in other fill areas,

and 1 test lift per 100 linear feet of utility trench backfill. Supervision by the field technician and

the project engineer is required. Some adjustments in the test frequencies may be required based

upon the general fill types and soil conditions at the time of fill placement.

Soil density verification is more than just a technician reading a dial on a meter, it involves

engineering judgment and a teamwork with the contractor. The process of geotechnical

engineering is not an exact science due to the inconsistencies of soil properties, approximation of

testing procedures, and judgment decisions.

Many problems can be avoided or solved in the field if proper inspection and testing services are

provided. It is recommended that all site and subgrade preparation, proofrolling, and pavement

EIKON


construction be monitored by a qualified engineering technician. Density tests should be

performed to verify proper compaction and moisture content of any earthwork. Inspection should

be performed prior to and during concrete placement operations. EIKON would be pleased to

assist you on this project.

EIKON


APPENDIX B

BORING LOGS AND

SUPPORTING DATA

Project #14167

www.eikoncg.com

SWELL TEST RESULTS

PROJECT: LOCATION: Ardmore, Oklahoma

CLIENT: Sunshine Industries BORING TYPE: Cont. Flight Auger

JOB NO.: 14167 DATE OF DRILLING: 8/18/2014

Boring

Number

Depth

feet

Initial Moisture

Content, %

Final Moisture

Content, %

Applied Pressure,

psf Vertical Swell, %

B2 1-2 9.4 19.2 96 3.5

B3 2-3 7.9 16.6 192 0.7

B3 4-5 12.2 16.1 385 6.7

P2 2-3 11.5 18.0 192 3.5

*Indicates partially dried sample to simulate drought conditions

SWELL TEST PROCEDURE:

Sunshine Adult

Day Services

A 3/4" thick sample is cut into a 2 1/2" diameter confining ring. The applied pressure reproduces the weight of the original

soil above the sample. Water enters through a porous stone until the sample is fully swollen.

BORING LOG B1

Sunshine Adult Day Services Ardmore, Oklahoma

Sunshine Industries Cont. Flight Auger

14167

N 12,12,16 11.3

11.2 17 45 28

5 N 14,25,33

N 20,16,26 6.1

10 N 50=3.0"

c

a

15 N b 50=4.0" 23.1

20 T

25 T

30

35

Notes: a Seepage at 13.0' b Water at 15.1' upon completion

c Water at 11.5' at end of day and caved to 24.0' d

Drilled by: Total Depth

LOCATION:

End of Boring: 25.0'

Liq

uid

Lim

it, %

Mo

istu

re C

on

ten

t %

BORING TYPE:

Un

ifie

d S

oil

Cla

ssific

ation

LAYER DESCRIPTION

Pla

sticity In

de

x

8/18/2014

Sw

ell,

%

Pa

ssin

g #

20

0 S

ieve

, %

Fin

e C

lays, %

Un

co

nfine

d C

om

pre

ssio

n

Str

en

gth

, p

sf

To

tal S

uction

, p

F

Dry

Un

it W

eig

ht, p

cf

DATE OF DRILLING:

PROJECT:

CLIENT:

JOB NO.:

Blo

ws/6

"

De

pth

- F

ee

t

Dia

gra

m

Sa

mp

le T

yp

e

Brown and Light Brown Sand

Brown and Reddish Brown

Sandy Clay

Red Brown and Gray Shale

Brown and Reddish Brown Sand

Pe

ne

tro

me

ter,

tsf

Pla

stic L

imit, %

Legend: S-Shelby TubeN-Standard PenetrationT-Texas Cone PenetrationB-BagC-Core

-Water Encountered

BORING LOG B2



14167

S 4.5 6.4

S 4.5 9.4 16 36 20 3.5

S 4.5 9.1 115 14724

N 8.1

5

N 13,14,14 6.2

10 N 41, 50=4.0" 11.3

b

a

15 N 43,50=4.5" 17.9

20

T

25 T

30

35


c Water at 12.0' at end of day and caved to 22.5' d


De

pth

- F

ee

t

Su

ction

, p

F

Pla

stic L

imit, %

Dia

gra

m

Un

ifie

d S

oil

Cla

ssific

ation

Sa

mp

le T

yp

e

Mo

istu

re C

on

ten

t %

PROJECT: LOCATION:

BORING TYPE:

DATE OF DRILLING:

Sw

ell,

%

LAYER DESCRIPTION

Liq

uid

Lim

it, %

Pla

sticity In

de

x

Pa

ssin

g #

20

0 S

ieve

, %

Dry

Un

it W

eig

ht, p

cf

Blo

ws/6

"

Brown Sandy Clay (Tan and Gray

Shaley Clay From 7 to 11 feet)

Red Shale

End of Boring 25.0'

CLIENT:

JOB NO.: 8/18/2014

Pe

ne

tro

me

ter,

tsf

Fin

e C

lays, %

Un

co

nfine

d C

om

pre

ssio

n

Str

en

gth

, p

sf


-Water Encountered

BORING LOG B3



14167

S 4.5 5.2

S 4.5 8.0 116 4471

S 4.5 7.9 15 39 24 0.7

S 4.5 8.4

5 S 4.5 12.2 6.7

N 37,38,18 12.0

10 N 14,32, 50=5" 12.0

15 N b 50=5.0" 11.9

a

20 N 27, 50=3.5"

25 N 18,31,47

30

35

Notes: a Seepage at 16' b Water at 15.9' upon completion

c d


Sw

ell,

%

Pla

stic L

imit, %

Liq

uid

Lim

it, %

Pla

sticity In

de

x

Pa

ssin

g #

20

0 S

ieve

, %

Un

co

nfine

d C

om

pre

ssio

n

Str

en

gth

, p

sf

Dry

Un

it W

eig

ht, p

cf

Su

ction

, p

F

8/18/2014JOB NO.:

De

pth

- F

ee

t

Sa

mp

le T

yp

e

Pe

ne

tro

me

ter,

tsf

Mo

istu

re C

on

ten

t %

Un

ifie

d S

oil

Cla

ssific

ation

LAYER DESCRIPTION

Blo

ws/6

"

Brown Sandy Clay (Tan and Gray

Shaley Clay From 7 to 11 feet)

Red and Gray Shale

End of Boring 25.0'

Dia

gra

m

Fin

e C

lays, %

LOCATION:

BORING TYPE:

DATE OF DRILLING:

PROJECT:

CLIENT:


-Water Encountered

BORING LOG P1


Sunshine Industries, Inc. Cont. Flight Auger

14167

S 4.5 9.6

S 4.0 7.9

S 1.75 10.2

S 0.5 24.3

5 S 1.75 15.2

10

15

20


c d


Brown Sandy Clay

End of Boring: 5.0'

Pe

ne

tro

me

ter,

tsf

Pla

stic L

imit,

%

PROJECT:

CLIENT:

JOB NO.:

Blo

ws/6

"

De

pth

- F

ee

t

Dia

gra

m

Sa

mp

le T

yp

e

8/18/2014

Sw

ell,

%

Pa

ssin

g #

20

0 S

ieve

, %

Fin

e C

lays,

%

Un

co

nfin

ed

Co

mp

ressio

n

Str

en

gth

, p

sf

To

tal S

uctio

n,

pF

Dry

Un

it W

eig

ht,

pcf

DATE OF DRILLING:

LOCATION:

Liq

uid

Lim

it,

%

Mo

istu

re C

on

ten

t %

BORING TYPE:

Un

ifie

d S

oil

Cla

ssific

atio

n

LAYER DESCRIPTION

Pla

sticity I

nd

ex


-Water Encountered

BORING LOG P2



14167

S 4.5 8.2

S 4.5 11.6

S 4.5 11.5 17 41 24 3.5

S 4.5 15.0

5 S 4.5 12.3

10

15

20

Notes: a b

c d


Brown Sandy Clay with Rusty

Seams

End of Boring: 5.0'

CLIENT:

JOB NO.: 8/18/2014

LOCATION:

BORING TYPE:

DATE OF DRILLING:

Sw

ell,

%

LAYER DESCRIPTION

Liq

uid

Lim

it,

%

Pla

sticity I

nd

ex

Pa

ssin

g #

20

0 S

ieve

, %

Dry

Un

it W

eig

ht,

pcf

Blo

ws/6

"

Pe

ne

tro

me

ter,

tsf

Fin

e C

lays,

%

Un

co

nfin

ed

Co

mp

ressio

n

Str

en

gth

, p

sf

De

pth

- F

ee

t

Su

ctio

n,

pF

Pla

stic L

imit,

%

Dia

gra

m

Un

ifie

d S

oil

Cla

ssific

atio

n

Sa

mp

le T

yp

e

Mo

istu

re C

on

ten

t %

PROJECT:


-Water Encountered

BORING LOG P3



14167

S 3.6

N 15,10,9 6.9

5 N 13,16,15 10.4

10

15

20

Notes: a b

c d


Brown Sand to 1.0' Brown

and Rusty Brown Sandy Clay

End of Boring: 5.0'

Dia

gra

m

Fin

e C

lays, %

LOCATION:

BORING TYPE:

DATE OF DRILLING:

PROJECT:

CLIENT:

JOB NO.:

De

pth

- F

ee

t

Sa

mp

le T

yp

e

Pe

ne

tro

me

ter,

tsf

Mo

istu

re C

on

ten

t %

Un

ifie

d S

oil

Cla

ssific

ation

LAYER DESCRIPTION

Blo

ws/6

"

Sw

ell,

%

Pla

stic L

imit, %

Liq

uid

Lim

it, %

Pla

sticity In

de

x

Pa

ssin

g #

20

0 S

ieve

, %

Un

co

nfine

d C

om

pre

ssio

n

Str

en

gth

, p

sf

Dry

Un

it W

eig

ht, p

cf

Su

ction

, p

F

8/18/2014


-Water Encountered

EIKON


APPENDIX C

MOISTURE CONTOL PROCEDURES

EIKON


MOISTURE CONTROL PROCEDURES

REASON FOR MOISTURE CONTROL

Buildings constructed on expansive soil have an inherent risk of movement and therefore distress

in the building regardless of how well the building is constructed or how much soil modification is

done prior to construction. Even structurally suspended foundations as described in the body of

this report need to have good moisture control procedures to minimize plumbing problems and

distress in sidewalks and driveways. The following procedures are recommendations which will

help to decrease the probability of distress in the building due to the expansive soils.

DESCRIPTION OF VARIOUS PROCEDURES

The following procedures are recommended for all buildings and yards surrounding the buildings,

which have expansive soils:

1. PROVIDE PROPER DRAINAGE

Positive drainage is important away from a building foundation in order to hopefully prevent

excessive moisture infiltration into the soils under the building. Good drainage is defined as a

slope of 10% for a distance of 10 feet away from the foundation. This is equivalent to a fall of

one foot in the first 10 feet away from the building. If there is a possibility of subsurface soil from

higher ground draining toward the building, install a drainage trench (French drain).

ILLUSTRATION OF GOOD DRAINAGE

EIKON


ILLUSTRATION OF DRAINAGE TRENCH

In contrast, poor drainage can cause a great increase in the probability of distress in a building

foundation. The following are examples of poor drainage:

Allowing a depression to occur at the drip line of the eaves of the building

Installing sidewalks at an elevation such that will not allow drainage away from the

building

Installing flower beds or shrubbery next to the building with curbs or grass retainers

which do not allow water to drain away from the building

Allowing dogs to dig next to the building leaving depressions which hold water

when it rains

Having any area which holds water when it rains

Allowing air conditioning drains to deposit next to a foundation

EIKON


ILLUSTRATIONS OF POOR DRAINAGE

2. PROVIDE PROPER LANDSCAPING

While it is acceptable and common to have flower, ground cover, shrubs, etc. next to a building,

the building owner should use certain parameters when planning a landscape:

Choose vegetation which has shallow root systems

Do not plant any shrubs, bushes, or small trees near the foundation which will have a mature

height greater than three feet

Do not use landscaping edges which cause water to pond

Plant any trees or large bushes a distance away from the foundation, which is equal to, or more

than the mature height of the tree.

DISTANCE OF TREE FROM BUILDING PRINCIPLE

3. SPRINKLER SYSTEMS

Sprinkler systems can be very effective in maintaining constant moisture around a building,

therefore minimizing the detrimental effects of expansive soils. A very good method is to provide

an equivalent of ½ inch of rain for a minimum of 6 feet and preferably 10 feet away from the

EIKON


foundation. It is not necessary to sprinkle any areas covered by sidewalks or driveways. It is also

important that the main sprinkler lines are not placed next to the foundation but all sprinkler heads

next to the foundation be supplied from a main line a minimum of 6 feet away from the building to

minimize any effects from leaking sprinkler lines. An alternative to this is to locate all heads 6 feet

away and sprinkle toward the building. The sprinkler system should be used all year but if a

minimum of ½ inch of rain is received in a weekly period, the sprinkler system may be suspended

for that time period.

ILLUSTRATION OF SPRINKLER SYSTEM

4. TREES

The management and or presence of trees is most likely the single most important factor in the

effects of expansive soils on building foundations. As the tree gets older, its root system gets

deeper and wider. Also, the tree desiccates (removes moisture) the soil, increasing the swell

potential of the soil. The following are examples of good tree management:

Choose trees with roots that are very shallow or go straight down. Trees with large root

systems such as oaks can be very detrimental to a foundation.

Place the building initially or plant trees later such that the building is no closer to the tree than

the tree is tall at maturity.

Water the tree regularly. Root feeders are very effective for minimizing the extent of the root

system.

Vertical Barriers may be used between the tree and the foundation to provide a stop for roots.

To be effective, the vertical barrier must be at least 5 feet deep and filled with concrete or an

impervious material.

EIKON


ILLUSTRATION OF TREE ROOT FEEDERS

ILLUSTRATION OF VERTICAL BARRIER USED TO BLOCK TREE ROOTS

5. PLUMBING

It is very common for water to follow plumbing trenches from the outside to underneath the

foundation. A plug of clay or concrete should be placed in the trench at the location where the

trench extends under the foundation.

EIKON


ILLUSTRATION OF A PLUMBING PLUG

The following are other methods to insure against plumbing problems:

1. Line all plumbing trenches with poly until the trench extends outside the building.

2. Collect all sewer lines outside the foundation line and only extend the plumbing under the

building at each drain location

3. Use overhead domestic water lines, which enter the building from the exterior and are

distributed in the building overhead.

4. Suspend the plumbing from the slab with a void beneath the plumbing.

6. DRIVEWAYS AND SIDEWALKS

Driveways and sidewalks should slope sufficiently away from the foundation such that if the soil

under the concrete swells up (heaves), the driveway will still slope away from the foundation. The

sidewalk or driveway should also be doweled to the area adjacent to the foundation to prevent a

step or separation from occurring between the driveway and foundation if movement occurs.

ILLUSTRATION OF DRIVEWAY SLOPE

EIKON


7. VERTICAL AND HORIZONTAL BARRIERS

An excellent method to protect the foundation from movement is to install a vertical or horizontal

barrier around the building. This barrier helps to maintain a constant moisture under the building.

Horizontal barriers are effective as long as the plastic is not penetrated when landscaping is

installed. They allow for more flexibility with installing plumbing under the building. Vertical

barriers are more effective but more difficult to install. This barrier is also difficult on plumbing as

it extends under the foundation. Barriers are not required as a part of the specific

recommendations for this site, but if a building owner wishes to decrease the probability of distress

as much as possible, these barriers will help.

ILLUSTRATIONS OF A HORIZONTAL BARRIER

EIKON


ILLUSTRATION OF VERTICAL BARRIER

CONCLUSION

As mentioned in this report, the only foundation type which will give the maximum protection

against distress in a building placed on expansive soils is a structurally suspended foundation.

However, with the above described moisture control practices, most slab on grade foundations

should perform satisfactorily and have little or no distress in a building. Even with these measures,

a highly expansive site (especially with deep seated swell) will have distress.

geotechnical report sunshine adult day services ardmore...

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