Soils Report.pdf

www.intertek.com/building

Intertek-PSI 2341 Spencerville Road Lima, Oh 45805

Tel +1 419 999 5660 Fax +1 419 999 6029 intertek.com/building

July 22, 2019

Ms. Xin ‘Cindy’ Wan WANIX Architects 4208 Prospect Avenue Cleveland, Ohio 44103

Re: Geotechnical Exploration Report Proposed Fuel Truck Garage Air National Guard 2660 South Eber Road Swanton, Ohio 44558 PSI Report No. 01252136

Dear Ms. Wan:

Per your request, Professional Service Industries, Inc. (PSI), an Intertek Company, is pleased to submit this Geotechnical Exploration Report for the proposed fuel truck garage in connection with the Air National Guard, located at 2660 South Eber Road in Swanton, Lucas County, Ohio. Included in this report are the results of the geotechnical exploration and recommendations concerning design and construction of the proposed development.

It is considered imperative that the geotechnical engineer and/or their representative be present during earthwork operations, foundation, and floor slab installations to observe the field conditions with respect to the design assumptions and specifications. PSI will not be held responsible for interpretations and field quality control observations made by others.

We appreciate the opportunity to have provided you with our geotechnical engineering services and look forward to participation in the construction phase of this project. If you have any questions concerning this report or if we may be of further service in any manner, please contact our office.

Respectfully submitted, PROFESSIONAL SERVICE INDUSTRIES, INC.

Tiffani Joseph, E.I. Alagaiya Veeramani, P.E.

Staff Engineer Director

The above Professional Engineering signature is an electronic reproduction of the original. An original hard copy is available upon request. This electronic reproduction shall not be construed as an original or certified document.

Enclosures

Geotechnical Exploration Report for

Fuel Truck Garage Air National Guard (ANG)

2660 South Eber Road Swanton, Ohio 44558

Prepared for

WANIX Architects

4208 Prospect Avenue Cleveland, Ohio 44103

Tiffani Joseph, EI Staff Engineer

Prepared by

Intertek-PSI 2341 Spencerville Road

Lima, OH 45805

Alagaiya Veeramani, P.E.

Report Date: July 22, 2019 Director

PSI Project No. 01252136

ANG Fuel Truck Garage

July 22, 2019

TABLE OF CONTENTS

1 PROJECT INFORMATION

1.1 PROJECT AUTHORIZATION

1.2 PROJECT DESCRIPTION

1.3 PURPOSE AND SCOPE OF SERVICES

2 SITE AND SUBSURFACE CONDITIONS

2.1 SITE LOCATION AND DESCRIPTION

2.2 SITE GEOLOGY

2.3 SUBSURFACE CONDITIONS

2.4 LABORATORY TESTING

2.5 GROUNDWATER LEVEL MEASUREMENTS

3 GEOTECHNICAL DISCUSSION

GROUNDWATER LEVELS/DRAINAGE

4 GEOTECHNICAL RECOMMENDATIONS

4.1 SITE PREPARATION

4.2 FOUNDATION RECOMMENDATIONS

4.3 EARTHQUAKE AND SEISMIC DESIGN CONSIDERATION

4.4 FLOOR SLAB RECOMMENDATIONS

4.5 UTILITIES TRENCHING

4.6 SILTATION CONTROL

5 CONSTRUCTION CONSIDERATIONS

5.1 MOISTURE SENSITIVE SOILS/WEATHER RELATED CONCERNS

5.2 DRAINAGE AND GROUNDWATER CONSIDERATIONS

5.3 EXCAVATIONS

6 GEOTECHNICAL RISK

7 REPORT LIMITATIONS

LIST OF APPENDICES

Boring Location Plan Boring Logs Laboratory Test Results General Notes Unified Soil Classification System (USCS)

July 18, 2019

1 PROJECT INFORMATION

1.1 PROJECT AUTHORIZATION

The following Table summarizes (in chronological order) the Project Authorization History for the services performed and represented in this report by Professional Service Industries, Inc. (PSI):

ANG FUEL TRUCK GARAGE

Document and Reference Number Date Requested/Provided By

Request for Proposal 6-5-2019 Ms. Xin (Cindy) Wan of WANIX Architects to Mr. Alagaiya Veeramani of Intertek-PSI

Intertek-PSI Proposal No.

0142-280665 6-10-2019 Ms. Xin (Cindy) Wan of WANIX Architects / Mr. Zaineddin

Obeid and Mr. Alagaiya Veeramani of Intertek-PSI Signed Intertek-PSI Proposal No. 0142- 280665

6-25-2019 Ms. Xin (Cindy) Wan of WANIX Architects

1.2 PROJECT DESCRIPTION

Based on the provided information, the proposed project will include construction of a single-story, prefabricated metal, slab-on-grade fuel truck garage structure at the Air National Guard facility. The proposed structure will be located immediately west of existing fuel tanks, T-1 and T-2, and will measure approximately 2,800 square feet in plan area.

Provided information indicates anticipated maximum column, wall, and floor loads will be less than 60 kips, 1 kip per lineal foot, and 250 pounds per square foot, respectively.

No topographical or grading information was provided at the time of this report. PSI has estimated maximum cut/fill operations of less than two (2) feet will be required to reach finish grades.

The geotechnical recommendations presented in this report are based on the available project information, the proposed location and orientation of the structure, and the subsurface materials described in this report. If any of the information we have is incorrect, please contact us so that we may amend the recommendations presented accordingly. PSI will not be responsible for the implementation of its recommendations when it is not notified of changes in the project.

1.3 SCOPE OF SERVICES

The purpose of this study was to explore the subsurface conditions at the site to prepare recommendations for foundation systems and other design parameters for the proposed development. PSI’s contracted scope of services included drilling a total of four (4) soil test borings, a select laboratory testing program, and preparation of this geotechnical report. This report briefly outlines the testing procedures, presents available project information, describes the site and subsurface conditions, and presents recommendations regarding the following:

Evaluation of the surface and subsurface conditions relative to the proposed construction, and identification of the physical and engineering characteristics of subsurface materials encountered during the sampling and testing.

Preparation of a geotechnical report, including Geotechnical Engineering recommendations, soil parameters and provisional data for use in design and construction of foundations and floor slab areas.

Recommendations for foundation design including bearing levels and bearing capacity.

Estimated seismic site classification as per IBC 2015.

Estimated total and differential settlements.

Recommendations for floor slab design, including subgrade preparation and Modulus of

Subgrade Reaction (k) value.

Recommendations for drainage, groundwater control, structural fill, and compaction.

Analysis and discussion of the possibility of liquefaction at the site including recommendations for ground modification or requirements for design of foundations and floor slabs, if applicable.

Other geotechnical factors/construction considerations that may impact development.

The scope of services did not include an environmental assessment for determining the presence or absence of wetlands, or hazardous or toxic materials in the soil, bedrock, surface water, groundwater, or air on, below, or around this site. Any statements in this report or on the boring logs regarding odors, colors, and unusual or suspicious items or conditions are strictly for informational purposes. Prior to further development of this site, an environmental assessment is advisable.

PSI’s scope also did not provide any service to investigate or detect the presence of moisture, mold or other biological contaminants in or around any structure, or any service that was designed or intended to prevent or lower the risk of the occurrence or the amplification of the same. The Client should be aware that mold is ubiquitous to the environment with mold amplification occurring when building materials are impacted by moisture. The Client should also be aware that site conditions are outside of PSI’s control, and that mold amplification will likely occur, or continue to occur, in the presence of moisture. As such, PSI cannot and shall not be held responsible for the occurrence or reoccurrence of mold amplification.

2 SITE AND SUBSURFACE CONDITIONS

2.1 SITE LOCATION AND CONDITIONS

The proposed project site area is located within the Air National Guard Facility located at 2660 South Eber Road in Swanton, Lucas County, Ohio. More specifically, the proposed structure will be located immediately west of existing fuel tanks, T-1 and T-2. The site latitude and longitude are approximately

41.5852 N and -83.7882 W, respectively.

Currently, the proposed site is predominately covered with grass and topsoil. No topographical information was provided at the time of this report; however, based on information gathered from Google Earthtm, the existing site appears to be relatively flat, with an apparent elevation difference of less than one (1) foot.

2.2 SITE GEOLOGY

Based on the on-line geologic map provided by the Ohio Geological Survey (available at http://www.dnr.state.oh.us/OhioGeologicalSurvey/SurficialGeology/tabid/23586/Default.aspx), the proposed site area is located in the Central Lowland Province, Huron-Erie Lake Plains Section, Maumee Lake Plains Region with Lake Deposit topography supported by Silurian bedrock as part of the Wisconsinan Glacial Period.

2.3 SUBSURFACE CONDITIONS

The scope of PSI’s services included a subsurface exploration program consisting of drilling and Standard Penetration Testing (SPT) at four (4) locations to depths of about 20 feet. The general test boring locations were selected and field located by Intertek-PSI.

The borings were advanced utilizing a 3¼ inch inside diameter, hollow-stem auger drilling methods. Soil samples were routinely obtained during the drilling process. Select soil samples were later tested in the laboratory to obtain soil material properties for the foundation and concrete slab-on-grade recommendations. Drilling, sampling, and laboratory testing was accomplished in general accordance with ASTM procedures.

The surface material thicknesses were determined in the field by measurements obtained during the drilling process. The surface of the proposed project area was covered with approximately 3 to 24 inches of topsoil. It must be recognized that these material thicknesses are approximate and should be expected to vary across the site areas.

Beneath the surficial materials, natural soils were encountered consisting of Poorly Graded Sand (SP), Poorly Graded Sand with Silt (SP-SM), and Silty Sand (SM). The natural soils were encountered to the boring termination depths of about 20 feet. The natural soils encountered had SPT values (N60) ranging from 3 to 33 blows per foot (bpf) and moisture contents from 17 to 25 percent.

The above subsurface description is of a generalized nature to highlight the major subsurface stratification features and material characteristics. The boring logs included in the Appendix should be reviewed for specific information at individual boring locations. These records include soil/rock descriptions, stratifications, penetration resistances, and locations of the samples and laboratory test data. The stratifications shown on the boring logs represent the conditions only at the actual boring locations. Variations may occur and should be expected between boring locations. The stratifications represent the approximate boundary between subsurface materials and the actual transition may be gradual. Water level information obtained during the field operations is also shown on these boring logs.

The samples that were not altered by laboratory testing will be retained for sixty (60) days from the date of this report and then will be discarded.

The following table summarize the blow counts, moisture contents, and water levels encountered during the field and laboratory study.

Table 2

B-

B-

B-

B-

Av er ag e

B-

B-

B-

B-

Av er ag e

1.0 4 3 6 3 4 1.0 19 22 22 25 21

3.5 6 11 11 10 9 3.5 22 19 19 22 20

6.0 10 22 11 11 14 6.0 22 20 22 19 21

8.5 4 11 6 3 7 8.5 23 21 20 23 21

13.5 33 32 30 28 32 13.5 19 22 19 18 20

18.5 7 15 12 28 11 18.5 19 19 17 19 18

6.0 3.0 5.5 4.0

4.0 3.0 3.0 3.0Water Level Reading Encountered Upon Completion

SUMMARY OF SPT N VALUES, MOISTURE CONTENT & GROUND WATER LEVELS

Groundwater Level Reading

To p of S oi l S am pl in g

De pt h

(f t)

To p of S oi l S am pl in g

De pt h

(f t)

Water Level Encountered While Drilling

SPT N Values (blows/ft) Moisture Content (%)

2.4 LABORATORY TESTING

Laboratory testing was conducted on selected split spoon samples obtained during the field drilling operations including grain size and moisture contents. The results of this testing are represented in the following table.

Table 3

Soil Grain Size Analysis Boring

No.

Sample

Depth (feet) Gravel

Sand

Silt and Clay

B-1 6 to 7-1/2 0.0 97.3 2.7 B-3 13-1/2 to 15 0.0 77.2 22.8 B-4 1 to 2-1/2 0.0 90.3 9.7

2.5 GROUNDWATER LEVEL MEASUREMENTS

Groundwater was encountered during drilling at the test boring locations at depths ranging from approximately 3 to 6 feet beneath the existing surface grades. Groundwater was also encountered upon completion of drilling operations at the test boring locations at depths ranging from approximately 3 to 4 feet beneath the existing surface grades. However, it must be recognized that free groundwater levels can significantly fluctuate (seasonally) and as a function of rainfall and may be present at other locations or to depths shallower than those encountered. During a time of year or weather different from the time of drilling, there may be a considerable change in the water table or the occurrence of water where not previously encountered. Furthermore, the free groundwater levels in the boreholes often are not representative of the actual groundwater level, because the boreholes remain open for a relatively short time. In fine-grained glacial soils, the depth of the soil color change from brown to gray can be an indicator of the prevailing groundwater level. Above the prevailing groundwater level, fine-grained soils oxidize to a brown color. Change in color of soil from brown to gray was observed during our field investigation at a depth of approximately 3 to 12 feet. To obtain longer-term measurements, it is necessary to install water level observation wells or piezometers. The water level measurements presented in this report are the levels that were measured at the time of PSI’s field activities. Therefore, we recommend that the contractor determine the actual groundwater levels at the time of construction to evaluate groundwater impact on the construction procedures.

3 GEOTECHNICAL DISCUSSION

The project field exploration has revealed one (1) primary concern at this site which may affect the performance of foundations or the slab for this project. The following paragraph summarizes this concern.

Groundwater Levels / Drainage

Groundwater was encountered within the proposed building footprint during drilling and upon completion of drilling at the test boring locations at depths ranging from 3 to 6 feet beneath the existing surface grades. It must also be recognized that groundwater and perched water conditions can significantly fluctuate, and water may also be present where not previously encountered.

Based on all encountered water levels noted above, temporary dewatering systems will likely be required during site excavations. A final determination can be made upon review of a site grading plan between the site civil engineer and PSI.

4 GEOTECHNICAL RECOMMENDATIONS

The following geotechnical related recommendations have been developed based upon the subsurface conditions encountered, our experience with similar soils and site conditions, and PSI’s understanding of the proposed development. Should changes in the project criteria occur, a review must be made by PSI to determine if modifications to our recommendations will be required.

4.1 SITE PREPARATION

PSI recommends that all topsoil, soft/loose, organic, frozen, or otherwise objectionable soils in the construction areas be removed and either wasted or stockpiled for later use in non-structural areas. It should be noted that it is not unusual for topsoil, fill materials, or other objectionable material thicknesses to vary from the values observed in the soil test borings. A representative of the geotechnical engineer should determine and document the depth of removal at the time of construction.

A proofroll should also be observed in areas that were undercut by a representative of the geotechnical engineer prior to adding engineered fill.

In this region, these otherwise competent sands, silts and lean clays can undergo a significant loss of stability when construction activities are performed during wetter portions of the year. PSI anticipates that the soils in the project area can become easily disturbed if subjected to conventional rubber tire or narrow track-type equipment. Soils that become disturbed would need to be excavated and replaced; however, this remedial excavation may expose progressively wetter soils with depth, thus compounding the situation.

Therefore, a normal approach to subgrade preparation may not be possible. Appropriate wide-track equipment selection should aid in minimizing potential disturbance.

After stripping to the proposed subgrade level and replacing unsuitable fill soils and/or objectionable soils if present, with engineered fill, as required, the building and paving areas should be proof-rolled with a loaded tandem-axle dump truck or similar heavy rubber-tired vehicle (typically with an axial load greater than nine

(9) tons). Soils that are observed to rut or deflect excessively (typically greater than one (1) inch) under the moving load should be undercut and replaced with properly compacted low plasticity fill material. The proof-rolling and undercutting activities should be witnessed by a representative of the geotechnical engineer and should be performed during a period of dry weather. If the earthwork activities take place during wet seasons, lime stabilization of the subgrade could be required prior to engineered fill placement.

Care should be taken during construction activities not to allow excessive drying or wetting of exposed soils.

The subgrade soils should be scarified and compacted to at least 98% of the materials’ standard Proctor maximum dry density, in general accordance with ASTM procedures, to a depth of at least twelve (12) inches below the surface. Additionally, new fill for building structures, asphalt, and concrete should not be placed on soft or frozen ground.

After subgrade preparation and observation have been completed, fill placement required to establish grade may begin. Low plasticity structural fill materials should be free of organic or other deleterious materials and have a maximum particle size of less than three (3) inches. Low-plasticity soils are defined as having a liquid limit less than forty-five (45) and plasticity index between ten (10) and twenty (20). Samples of proposed fill materials should be provided to PSI well in advance of their use to determine if the proposed fill material is suitable for use at the project. Additionally, a representative of PSI should be on-site to observe, test, and document placement of the fill. If the fill is too dry, water should be uniformly applied and thoroughly mixed into the soil by disking or scarifying. Close moisture content control will be required to achieve the recommended degree of compaction. If wet or cool season earthwork is necessary, PSI recommends the use of imported fill materials meeting the requirements of Ohio Department of Transportation (ODOT) No. 304 aggregate.

Fill should be placed in maximum loose lifts of eight (8) inches and compacted to at least 98% of the materials’ standard Proctor maximum dry density, and within a range of the optimum moisture content as designated in the table below, as determined in general accordance with ASTM procedures. Each lift of compacted-engineered fill should be tested and documented by a representative of the geotechnical engineer prior to placement of subsequent lifts. The edges of compacted fill should extend a minimum of five (5) feet beyond the building footprint, or a distance equal to the depth of fill beneath the footings, whichever is greater. The measurement should be taken from the outside edge of the footing to the toe of the excavation prior to sloping.

In utility trenches, shallow foundation excavations, and other areas where large compaction equipment cannot be used, granular engineered fill should be placed as backfill. PSI recommends the use of material meeting Ohio Department of Transportation (ODOT) No. 304, for use as granular engineered fill. Engineered fill should be placed in accordance with the recommendations stated in this section of the report.

The fill placed should be tested and documented by a geotechnical technician and directed by a geotechnical engineer to evaluate the placement of fill material. It should be noted that the geotechnical engineer of record can only certify the testing that is performed, and the work observed by that engineer or staff in direct report to that engineer. The fill should be evaluated in accordance with the following Table:

Table 4

MATERIAL TESTED PROCTOR

TYPE

MIN % DRY

DENSITY

PLACEMENT

MOISTURE

CONTENT

RANGE

FREQUENCY OF

TESTING *1

Structural Lean Clay Fill (Cohesive)

Standard 98% -2 to +2 % 1 per 5,000 ft2 of fill placed / lift

Structural Fill (Granular) Standard 98% -2 to +2 % 1 per 5,000 ft2 of fill placed / lift

Random Fill (non-load bearing)

Standard 90% -3 to +3 % 1 per 6,000 ft2 of fill placed / lift

Utility Trench Backfill Standard 98% -2 to +2 % 1 per 150 lineal foot / lift

*1 Minimum 2 per lift.

Tested fill materials that do not achieve either the required dry density or moisture content range shall be recorded, the location noted, and reported to the Contractor and Owner. A re-test of that area should be performed after the Contractor performs remedial measures and prior to the placement of additional fill material.

4.2 FOUNDATION RECOMMENDATIONS

Provided information indicates anticipated maximum column and wall loads will be less than 60 kips and 1 kip per lineal foot, respectively. Accordingly, the columns and walls can be supported on conventional spread-type footing foundations bearing on either competent naturally deposited soils or properly compacted, tested, and documented engineered fill. If it is desired for the planned foundations to bear on properly compacted and documented fill, the geotechnical engineer should be allowed to review the material to determine its consistency with the recommended bearing pressures. Spread footings for structure columns and continuous footings for bearing walls can be designed using a maximum allowable soil bearing pressure of 2,000 pounds per square foot (psf) based on dead load plus design live load. This value contains a safety factor of 3 against ultimate soil failure. PSI recommends a minimum dimension of thirty (30) inches for square footings and eighteen (18) inches for continuous footings to minimize the possibility of a local bearing capacity failure.

It should be noted that groundwater was encountered at depths as shallow as 3 feet below existing grade and could be encountered at shallower depths in other locations. The groundwater must be lowered and maintained to a level that is at least 2 feet below the deepest excavation at the site until the area is backfilled to the existing ground elevation. Additionally, permanent foundation drains may be necessary.

Exterior footings and footings in unheated areas should be located at a depth of forty-two (42) inches or deeper below the final exterior grade to provide adequate frost protection. If the structure is to be constructed during the winter months or if footings will likely be subjected to freezing temperatures after foundation construction, then the footings should be protected from freezing. PSI recommends that interior footings be a minimum depth of eighteen (18) inches below the finished floor elevation.

The foundation excavations should be observed and documented by a representative of PSI prior to steel or concrete placement to determine that the foundation materials are consistent with the materials discussed in this report, and therefore can support the design loads. Soft or loose soil zones encountered at the bottom of the footing excavations should be removed to the level of suitable natural soils, and replaced with adequately compacted (granular) structural fill. Fill placed below the foundations where unsuitable materials are removed should extend one half (½) foot outside the foundation limits for every one (1) foot in thickness between the intended bearing surface and the underlying, suitable natural soils. Alternately, the foundations may be extended through unsuitable soils to bear on the underlying suitable material.

Cavities formed because of excavation of soft or loose soil zones should be backfilled with lean concrete or dense graded compacted crushed stone.

After opening, footing excavations should be observed, and concrete placed as quickly as possible to avoid exposure of the footing bottoms to wetting and drying. Surface run-off water should be drained away from the excavations and not be allowed to pond. If possible, the foundation concrete should be placed during the same day the excavation is made. If it is required that footing excavations be left open for more than one day, they should be protected to reduce evaporation or entry of moisture by placing a relatively thin seal slab of concrete.

Based on the known subsurface conditions and site geology, laboratory testing and past experience, PSI anticipates that properly designed and constructed footings supported on the recommended materials should experience total and differential settlement between adjacent columns of less than one (1) inch and ¾ inch, respectively.

Be advised that as a part of the foundation selection process, there is a cost/benefit evaluation. Although PSI is recommending a specific foundation type, we have not accomplished the cost/benefit evaluation.

4.3 EARTHQUAKE AND SEISMIC DESIGN CONSIDERATION

The 2015 International Building Code requires a site class for the calculation of earthquake design forces.

This class is a function of soil type (i.e., depth of soil and strata types). Based on the depth to rock and the estimated shear strength of the soil at the test boring locations, Site Class “D” is recommended. The United States Geological Survey National Earthquake Hazard Reduction Program (USGS-NEHRP) probabilistic ground motion values “D” are as follows:

Table 5 For Latitude 41.5852 N / Longitude -83.7882 W

Period (seconds) Site Coefficients

Max. Spectral Acceleration Parameters

Design Spectral Acceleration Parameters

0.120 (Ss) Fa = 1.6 Sms = 0.192 SDs= 0.128

0.054 (S1) Fv = 2.4 Sm1 = 0.131 SD1= 0.087

The Site Coefficients, Fa and Fv were interpolated from IBC 2015 Tables 1613.3.3 (1) and 1613.3.3 (2) as a function of the site classifications and the mapped spectral response acceleration at the short (Ss) and 1 second (S1) periods.

According to Section 1803.5.11 of IBC 2015, sites supporting structures in design category “C” and below must be evaluated for slope instabilities, liquefaction, and surface rupture due to faulting or lateral spreading. A detailed study of these effects was beyond PSI’s scope of services. However, the following table presents a qualitative assessment of these issues considering the site class, the subsurface soil properties, the groundwater elevation, and probabilistic ground motions:

Table 6

Hazard Relative Risk Comments Liquefaction Low The soil within the upper 50 feet of the subsurface profile is a relatively dense and/or cohesive soil Slope Stability Low The site is relatively flat and does not/will not incorporate significant cut or fill slopes Surface Rupture Low The site is not underlain by a mapped Holocene-aged fault

A more detailed evaluation of these issues can be performed for an additional scope and/or fee.

4.4 FLOOR SLAB RECOMMENDATIONS

The floor slab should be supported on properly placed, compacted, and tested fill or native low plasticity soil. Once the site area has been prepared in accordance with the “Site Preparation” section of this report, the floor slab can be grade supported on a minimum 2 feet non-expansive engineered fill. Proof-rolling, as discussed earlier in this report, should be accomplished to identify soft or unstable soils that should be removed from the floor slab area prior to fill placement and/or floor slab construction. These soils should be replaced with properly compacted structural fill as described earlier in this report.

PSI recommends that a minimum six (6) inch thick trimmable, compactable granular material be placed beneath the floor slab to enhance drainage. The soil surface shall be graded to drain away from the building without low spots that can trap water prior to placing the granular drainage layer. Polyethylene sheeting should be placed to act as a vapor retarder where the floor will be in contact with moisture sensitive equipment or products such as tile, wood, carpet, etc., as directed by the design engineer. The decision to locate the vapor retarder in direct contact with the slab or beneath the layer of granular fill should be made by the design engineer after considering the moisture sensitivity of subsequent floor finishes, anticipated project conditions, and the potential effects of slab curling and cracking. The floor slabs should have an adequate number of joints to reduce cracking resulting from differential movement and shrinkage.

For subgrade prepared as recommended and properly compacted fill, a modulus of subgrade reaction, k value, of 100 pounds per cubic inch (pci) may be used in the grade slab design based on correlation to values typically resulting from a 1 ft. x 1 ft. plate load test. However, depending on how the slab load is applied, the value should be geometrically modified. The value should be adjusted for larger areas using the following expression for cohesive and cohesionless soil:

Modulus of Subgrade Reaction, ks = ( B k

) for cohesive soil and ks = k ( B

B

)2 for cohesionless soil where: ks = coefficient of vertical subgrade reaction for loaded area, k = coefficient of vertical subgrade reaction for 1 square foot area, and

B = effective width of area loaded, in feet

The precautions listed below should be followed for construction of slab-on-grade pads. These details will not reduce the amount of movement, but are intended to reduce potential damage should some settlement of the supporting subgrade take place. Some increase in moisture content is inevitable because of development and associated landscaping. However, extreme moisture content increases can be largely controlled by proper and responsible site drainage, building maintenance and irrigation practices.

Cracking of slab-on-grade concrete is normal and should be expected. Cracking can occur not only because of heaving or compression of the supporting soil and/or bedrock material, but also because of concrete curing stresses. The occurrence of concrete shrinkage cracks, and problems associated with concrete curing may be reduced and/or controlled by limiting the slump of the concrete, proper concrete placement, finishing, and curing, and by the placement of crack control joints at frequent intervals, particularly where re-entrant slab corners occur. The American Concrete Institute (ACI) recommends a maximum panel size

(in feet) equal to approximately three times the thickness of the slab (in inches) in both directions. For example, joints are recommended at a maximum spacing of twelve (12) feet based on having a four-inch slab. PSI also recommends that the slab be independent of the foundation walls. Using fiber reinforcement in the concrete can also control shrinkage cracking.

Areas supporting slabs should be properly moisture conditioned and compacted. Backfill in all interior and exterior water and sewer line trenches should be carefully compacted to reduce the shear stress in the concrete extending over these areas.

Exterior slabs should be isolated from the building. These slabs should be reinforced to function as independent units. Movement of these slabs should not be transmitted to the building foundation or superstructure.

4.5 UTILITIES TRENCHING

Excavation for utility trenches shall be performed in accordance with OSHA regulations as stated in 29 CFR Part 1926. It should be noted that utility trench excavations have the potential to degrade the properties of the adjacent fill materials. Utility trench walls that can move laterally can lead to reduced bearing capacity and increased settlement of adjacent structural elements and overlying slabs.

Backfill for utility trenches is as important as the original subgrade preparation or structural fill placed to support either a foundation or slab. Therefore, it is imperative that the backfill for utility trenches be placed to meet the project specifications for the structural fill of this project. PSI recommends that flowable fill or lean mix concrete be utilized for utility trench backfill. If on-site soils are placed as trench backfill, the backfill for the utility trenches should be placed in four (4) to six (6) inch loose lifts and compacted to a minimum of 98% of the maximum dry density achieved by the standard Proctor test.

The backfill soil should be moisture conditioned to be within 2% of the optimum moisture content as determined by the standard Proctor test. Up to four (4) inches of bedding material placed directly under the pipes or conduits placed in the utility trench can be compacted to the 90% compaction criteria with respect to the standard Proctor. Compaction testing should be performed for every 200 cubic yards of backfill place or each lift within 200 linear feet of trench, whichever is less. Backfill of utility trenches should not be performed with water standing in the trench. If granular material is used for the backfill of the utility trench, the granular material should have a gradation that will filter protect the backfill material from the adjacent soils. If this gradation is not available, a geosynthetic non-woven filter fabric should be used to reduce the potential for the migration of fines into the backfill material. Granular backfill material shall be compacted to meet the above compaction criteria. The clean granular backfill material should be compacted to achieve a relative density greater than 75% or as specified by the geotechnical engineer for the specific material used.

4.6 SILTATION CONTROL

The Clean Water Act, implemented in 1990 includes a federal permit program called the National Pollutant Discharge Elimination System (NPDES). This program requires that projects sites more than one (1) acre or are part of a development which exceeds one (1) acre be covered under a permit. This typically includes the development of a storm water pollution prevention plan (SWPPP) as well as period inspections (typically once a week plus after significant rainfall). PSI is available to assist with these services.

5 CONSTRUCTION CONSIDERATIONS

PSI should be retained to provide observation and testing of construction activities involved in the foundation, earthwork, and related activities of this project. PSI cannot accept responsibility for conditions that deviate from those described in this report, nor for the performance of the foundation system if not engaged to also provide construction observation and testing for this project.

5.1 MOISTURE SENSITIVE SOILS/WEATHER RELATED CONCERNS

The soils encountered at this site will be sensitive to disturbances caused by construction traffic and to changes in moisture content. During wet weather periods, increases in the moisture content of the soil can cause significant reduction in the soil strength and support capabilities. In addition, soils that become wet may be slow to dry and thus significantly retard the progress of grading and compaction activities. It will, therefore, be advantageous to perform earthwork and foundation construction activities during dry weather.

5.2 DRAINAGE AND GROUNDWATER CONSIDERATIONS

Groundwater was encountered during drilling at the test boring locations at depths ranging from approximately 3 to 6 feet beneath the existing surface grades. Groundwater was also encountered upon completion of drilling operations at the test boring locations at depths ranging from approximately 3 to 4 feet beneath the existing surface grades. However, PSI recommends that the Contractor determine the actual groundwater levels at the site at the time of the construction activities to assess the impact groundwater may have on construction. The groundwater level must be lowered and maintained at a level 2 feet below the deepest excavation at the site until the area is backfilled to the ground surface. If the groundwater level is not sufficiently lowered, then the soils can become “quick” which will result in an unstable bearing area and increased settlement and possible distress as load is applied to the structure.

Additionally, permanent foundation drains may be necessary.

Water should not be allowed to collect in the foundation excavation, on floor slab areas, or on prepared subgrades of the construction area either during or after construction. Undercut or excavated areas should be sloped toward one corner to facilitate removal of collected rainwater, groundwater, or surface runoff.

Positive site drainage should be provided to reduce infiltration of surface water around the perimeter of the building and beneath the floor slabs. The grades should be sloped away from the building and surface drainage should be collected and discharged such that water is not permitted to infiltrate the backfill and floor slab areas of the building. Overall site area drainage is to be arranged in a manner such that the possibility of water impounding below slab-on-grade areas and over the structural fill, is prevented at all times during and after construction.

Seasonal variations will cause fluctuations or a water table to be present in the upper soils. Additionally, perched water may be encountered in discontinuous zones within the overburden. If present, water should be removed from excavations by pumping. If excessive water seepage occurs or if the rate of seepage cannot be controlled with normal pumping techniques, the Geotechnical engineer should be consulted.

5.3 EXCAVATONS

In Federal Register, Volume 54, Number 209 (October 1989), the United States Department of Labor, Occupational Safety and Health Administration (OSHA) amended its "Construction Standards for Excavations, 29 CFR, part 1926, Subpart P". This document was issued to better enhance the safety of workers entering trenches or excavations. It is mandated by this federal regulation that excavations, whether they be utility trenches, basement excavation or footing excavations, be constructed in accordance with the new OSHA guidelines. It is PSI’s understanding that these regulations are being strictly enforced and if they are not closely followed, the owner and the contractor could be liable for substantial penalties.

Care must be taken to protect adjacent structure foundations and structures during the foundation excavation process, so no structure or foundation is undermined. All existing foundations must be protected during the installation process. In addition, care must be taken to maintain the groundwater level at least 2 feet below the deepest excavation at the site to reduce the potential for unstable soil conditions.

The contractor is solely responsible for designing and constructing stable, temporary excavations and should shore, slope, or bench the sides of the excavations as required to maintain stability of both the excavation sides and bottom. The contractor's "responsible person", as defined in 29 CFR Part 1926, should evaluate the soil exposed in the excavations as part of the contractor's safety procedures. In no case, should slope height, slope inclination, or excavation depth, including utility trench excavation depth, exceed those specified in local, state, and federal safety regulations.

PSI is providing this information solely as a service to our client. PSI does not assume responsibility for construction site safety or the contractor's or other parties’ compliance with local, state, and federal safety or other regulations. A trench safety plan was beyond the scope of our services for this project.

6 GEOTECHNICAL RISK

The concept of risk is an important aspect of the geotechnical evaluation. The primary reason for this is that the analytical methods used to develop geotechnical recommendations do not comprise an exact science.

The analytical tools which geotechnical engineers use are generally empirical and must be used in conjunction with engineering judgment and experience. Therefore, the solutions and recommendations presented in the geotechnical evaluation should not be considered risk-free and, more importantly, are not a guarantee that the interaction between the soils and the proposed structure will perform as planned. The engineering recommendations presented in the preceding section constitutes PSI’s professional estimate of those measures that are necessary for the proposed structure to perform per the proposed design based on the information generated and referenced during this evaluation, and PSI’s experience in working with these conditions.

7 REPORT LIMITATIONS

The recommendations submitted in this report are based on the available subsurface information obtained by PSI for the proposed Air National Guard Fuel Truck Garage. If there are any revisions to the plans for the proposed development or if deviations from the subsurface conditions noted in this report are encountered during construction, PSI should be retained to determine if changes in the recommendations are required.

If PSI is not retained to perform these functions, PSI will not be responsible for the impact of those conditions on the geotechnical recommendations for the project.

The Geotechnical Engineer warrants that the findings, recommendations, specifications, or professional advice contained herein, have been presented after being prepared in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics and engineering geology. No other warranties are implied or expressed.

This report has been prepared for the exclusive use of WANIX Architects for the specific application to the proposed Air National Guard Fuel Truck Garage located within the Air National Guard Facility at 2660 South Eber Road in Swanton, Lucas County, Ohio.

APPENDIX

Bo rin g Lo ca tio n Pl an

AN

G Fu el T ru ck

G ar ag e

S ou th E be r R oa d

Sw an to n, Lu ca s C ou nt y, O hi o

Pr of es si on al

S er vi ce

In du st rie s

Dr aw in g

Pr ov id ed b y

W

AN

IX

A rc hi te ct s

PS

I P ro je ct N o.

No rt h

B -1

B -4

-a pp ro xi m at e bo rin g lo ca tio ns

B -2

B -3