Geotech_Report_LSGA019179.pdf

Report Proposed Replacement

Fire Crash/Rescue Station 125th Fighter Wing

National Guard Bureau Facility Jacksonville, Duval County, Florida

LSGA019179

Task Order 2W02

Contract W9133L-15-D-0002 PSI Project No. 07571447

Professional Service Industries, Inc. 1748 33rd Street Orlando FL 32839 Phone 407/304-5560 Fax 407/304-5561

Engineering Certificate of Authorization 3684

March 14, 2016

Jacobs 200 S. Orange Avenue Suite 900 Orlando, Florida 32801

Attn: Mr. Scott Herlitzka, AIA Managing Principal

RE: Report

Proposed Replacement Fire Crash/Rescue Station 125th Fighter Wing National Guard Bureau Facility Jacksonville, Duval County, Florida

LSGA019179

Task Order 2W02 Contract W9133L-15-D-0002 PSI Project No. 07571447

Dear Mr. Herlitzka:

In accordance with PSI Proposal No. 757-159319 and your authorization by way of Subconsulting Agreement No. FDZD3006-S16-0001 executed on October 30, 2015, Professional Service Industries, Inc. (PSI) has provided design-level geotechnical engineering services for the referenced project. This report presents the results of our field exploration program and includes geotechnical recommendations to guide design and construction of the project.

PROJECT INFORMATION

The proposed location of the project is at the Air National Guard Facility at Jacksonville International Airport in Jacksonville, Florida. The facility is located on the west side of the airport and includes existing fighter jet taxiways, hangers, office buildings, roadways and related infrastructure. The majority of the site is a greenfield site. There are existing swales to the south of the site. Areas of saturated soils were present at the time of our evaluation and standing water was present in the historical aerial images of the site. Aerial photography also indicates that the southwest portion of the site was previously used for equipment storage and parking.

We understand the project will consist of the construction of an approximately 16,800 square feet, single-story building with associated concrete aprons and a new access road. We have not been provided with structural loading information but for the purpose of this report we assume the building will be a steel-framed structure with maximum column and wall foundation loads of 150 kips and 5 kips per lineal foot, respectively. We assume maximum floor loads will be 250 pounds per square foot and that the ground floor slab will be constructed within 2 feet of existing grade.

Jacobs March 14, 2016 PSI Project No. 07571447 Page 2 of 11

New pavements will consist of concrete aprons and access road(s). We have not been provided with the exact configuration of the aprons and access roads.

It is our understanding that the existing stormwater swales will be used for stormwater management for the project.

The above listed information/assumptions have been used for the purpose of preparing this report.

Adjustments to our recommendations may be necessary if the planned development differs from the noted information/assumptions.

REVIEW OF PUBLISHED DATA

USGS Topographic Map

The topographic survey map published by the USGS entitled “Trout River, Florida” was reviewed for ground surface features in the area of the proposed development. Based on this review, the natural ground surface elevation is at about +20 feet National Geodetic Vertical Datum of 1929 (NGVD29) in the general project vicinity. We were not provided with any site specific topographic information for comparison with the USGS data.

SCS Soil Survey

The “Soil Survey of Duval County, Florida,” published by the USDA SCS, was reviewed for general near-surface soil information within the general project vicinity. This information indicates that there are three soil groups at the proposed project site. The mapped soil units are summarized in the following table.

Soil Series Depth

(inches) Unified

Classification

USDA Seasonal High Groundwater Table

Depth (feet)

7 – Arents, nearly level 0 to 80 SP, SP-SM 1.5 to 3 38 – Mascotte fine sand, 0 to 2 percent slopes

0 to 80

SP-SM, SM, SC,

SC-SM

0.5 to 1.5

69 – Urban Land * * *

*Information not provided by the SCS.

PSI Project No. 07571447 Page 3 of 11

SUBSURFACE CONDITIONS

General

As requested, to evaluate subsurface conditions at the site of the proposed project PSI performed four (4) Standard Penetration Test (SPT) borings in the proposed building footprint to depths of 25 to 30 feet below the existing ground surface. Two of the originally proposed boring locations were on airport property near a taxiway. Due to the difficulty associated with obtaining permission to perform the SPT borings in that area, after consulting with you we instead offset the SPT boring locations inside a fence line and performed an additional manual auger boring at each of the planned building borings locations. The SPT borings were drilled using rotary wash procedures and sampled following Standard Penetration Test (SPT) techniques in general accordance with ASTM D-1586. In the SPT borings, samples were collected and Standard Penetration Test resistances (N-values) measured virtually continuously from four to ten feet and on intervals of five (5) feet thereafter to boring termination. The upper four feet of each boring was augured manually to confirm utility clearance. Therefore, SPT readings were not obtained in that interval.

We also performed nine (9) manual auger borings in possible pavement areas to depths of five to seven feet below the existing ground surface. The shallower borings were terminated prior to reaching the seven feet planned depth due to the presence of shallow groundwater which prevented us from advancing the manual auger borings further. In the auger borings, samples were obtained from the flights of the augers at each change in stratum.

The borings were drilled at the approximate locations shown on Sheet 1. They were located using a hand-held GPS device and the project plan provided to us. The borings were backfilled with soil cuttings prior to leaving the site.

The soil samples recovered from the borings were returned to our Orlando laboratory for visual stratification and laboratory testing. Soils were visually stratified following the guidelines contained in the Unified Soil Classification System (USCS). Records of the materials encountered in the borings are presented as soil profiles on Sheets 2 and 3. Sheets 2 and 3 include a legend describing the soils in USCS format and measured groundwater levels. Laboratory test results are provided on Sheets 2 and 3 adjacent to the borings and depths from which the test samples were obtained.

The stratification presented is based on visual observation of the recovered soil samples, laboratory testing and interpretation of field logs by a geotechnical engineer. It should be noted that variations in the subsurface conditions are expected and may be encountered between and away from the borings. Also, whereas the individual boring logs indicate distinct strata breaks, the actual transition between the soil layers may be more gradual than shown on the soil profiles.

PSI Project No. 07571447 Page 4 of 11

Soil Conditions

In borings HA-5 and HA-7, a surficial layer of gravel approximately six inches thick was encountered. In the other borings, the ground surface consisted of exposed soil or short vegetation.

Based on the results of the borings completed for the project, subsurface conditions are relatively consistent across the site. Below the surface gravel/vegetation, the borings revealed a series of fine sands grading silty and clayey in composition (i.e. SM and SC materials) from the existing ground surface to depths of 5 to 30 feet below the existing ground surface.

Based on the SPT blow counts recorded during our field exploration, the sands generally grade loose to medium-dense with a very loose layer encountered in boring B-3 at a depth of about

23.5 feet below the existing ground surface.

A detailed description of the individual borings is shown on the soil profiles on Sheets 2 and 3 in the Appendix.

Groundwater Conditions

Groundwater was encountered at depths of 2 to 4 feet below the existing ground surface in the borings at the time they were drilled (March 1 and 2, 2016) except for boring HA-6, in which groundwater was not encountered at the time the boring was performed (March 2, 2016). Please note that aerial photography appears to indicate the previous presence of standing water on the site and the drill crew noted that the ground was very moist in isolated low areas between boring locations.

The estimated normal seasonal high groundwater levels presented herein are based on the observed soil stratigraphy, conditions observed in the borings, USDA Soil Survey information, and our past experience in the project vicinity. In this regard, we estimate the depth to the normal seasonal high groundwater table (SHWT) to occur within one-half foot of the natural ground surface. The normal seasonal high groundwater table appears to be slightly above the existing ground surface in lower areas of the site. More detailed groundwater information can be provided once site-specific topographic information is provided to PSI.

In general, the normal seasonal high groundwater level is not intended to define a limit or ensure that future seasonal fluctuations in groundwater levels will not exceed the estimated levels.

Groundwater conditions will vary with environmental changes and seasonal conditions, such as the frequency and magnitude of rainfall patterns, as well as man-made influences, such as swales, drainage ponds, underdrains and areas of covered soil (buildings, paved parking lots, sidewalks, etc.).

PSI Project No. 07571447 Page 5 of 11

SITE SUITABILITY

Based on the results of PSI’s borings, it is our opinion that soil conditions are generally suitable for the proposed building construction from a geotechnical engineering perspective. Following completion of site preparation as recommended herein, shallow spread foundations can be used for building support. Such foundations can be designed for a net allowable bearing pressure of 2,500 pounds per square foot (psf).

Pavements can be constructed of flexible asphalt or rigid concrete sections provided a minimum separation of 18 inches is maintained between the bottom of the pavement basecourse and the normal seasonal high groundwater table, and provided that our other recommendations in this report are followed.

SITE PREPARATION

General

The following recommendations have been developed on the basis of the previously described project characteristics and subsurface conditions encountered. If there is any change in the project criteria, including the location or orientation of the proposed structure, a review must be made by PSI to determine if additional fieldwork and/or any modifications to our recommendations will be required.

Once final design plans and specifications are available, a general review by PSI is strongly recommended as a means to check that the evaluations made in preparation of this report are correct and that earthwork, pavement and foundation recommendations are properly interpreted and implemented.

Site Clearing/Stripping

At the outset of construction, clearing and grubbing including root raking and removal of any organic-laden topsoil that may remain on the site should be completed. This normally includes removing the surface vegetation, stripping topsoil, grubbing major root systems, and removing any miscellaneous debris and/or other deleterious materials. At a minimum, it is recommended that the clearing/stripping operations extend at least ten feet beyond the proposed building perimeter, where possible. Material generated during stripping operations should be disposed of off-site in a proper manner as directed by the Owner.

Initial site clearing and preparation work should be carried out under the observation of a representative of the geotechnical engineer.

PSI Project No. 07571447 Page 6 of 11

Fill Placement and Subgrade Preparation

Following the clearing/stripping operations, the exposed subgrade should be evaluated as directed by representatives of PSI to confirm that all unsuitable materials have been removed. The structure and pavement areas should then be proof-rolled to provide a stable/unyielding subgrade prior to placing fill. Proof rolling should consist of compaction with a large diameter, vibratory drum roller.

Proof rolling should consist of a minimum of ten overlapping coverages of the roller in a criss-cross pattern with a maximum travel speed of 2 feet per second.

Compaction can be completed in the vibratory or static mode in order to meet the minimum density requirements stated below. Based on past experience, we recommend compaction equipment be operated in the static mode within 75 feet of existing structures to reduce vibrations that could cause structural distress or disturb building occupants. Careful observations should be made during proof rolling to help identify any areas of soft/yielding soils that may require over-excavation and replacement filling.

For the building and pavement areas, we recommend that the natural ground, to a minimum depth of one foot below stripped grade, be compacted to at least 95 percent of the material’s modified Proctor (ASTM D-1557) maximum dry density. Following satisfactory completion of initial compaction of the stripped subgrade, the proposed development area may be brought up to finished grades as required.

Engineered Fill

Any off site fill imported for the project should consist of clean fine sand with less than 12 percent by dry weight passing the U.S. Standard No. 200 sieve and be free of rubble, organics, clay, debris and other deleterious material. Fill should be tested and approved prior to import and placement.

Each lift should have a loose thickness not exceeding 12 inches. Density tests should be performed to confirm the required compaction is being achieved prior to placing the next lift.

Prior to beginning compaction, soil moisture conditioning may be required. Soil moisture contents should be controlled in order to facilitate proper compaction. A moisture content within two percentage points of the material’s optimum indicated by the modified Proctor test (ASTM D-1557) is recommended prior to compaction of the natural ground and fill. All engineered fill should be compacted to at least 95 percent of the material’s modified Proctor (ASTM D-1557) maximum dry density.

On-Site Soil Suitability

Materials to be used for backfill or compacted fill for construction should be evaluated and, if necessary, tested by PSI prior to placement to determine if they are suitable for the intended use.

Based on the boring results, the on-site soils (Strata 1, 2 and 3) contained a significant amount of silt and/or clay and will be difficult to moisture condition and compact, especially during the wet season. If it is desired to use the silty and/or clayey sands (Strata 1, 2 and 3), they should be combined with other, more suitable materials in such a way that the content of fines of the hybrid material is less than 12 percent passing the No. 200 sieve. Samples of the soil to be used as fill should be taken during excavation as necessary to verify that the soils meet this requirement.

PSI Project No. 07571447 Page 7 of 11

DESIGN RECOMMENDATIONS

Foundations

Based on the anticipated construction and recommended site preparation, shallow foundations can be used for structure support. Such foundations may be designed for a net allowable bearing pressure of 2,500 pounds per square foot (psf). The foundations and floor slabs should bear on properly placed and compacted cohesionless (sand) fills or on compacted native soils. All footings should be embedded so that the bottom of the foundation is a minimum of 18 inches below adjacent finished grades on all sides. Strip, wall and turndown foundations should be a minimum of 18 inches wide, while column footings should be at least 30 inches square.

The subgrade soils should be compacted to a minimum density requirement of 95 percent of the material’s modified Proctor (ASTM D-1557) maximum dry density for a minimum depth of two feet below the bottom of footings, as determined by field density compaction tests. Backfill soils placed adjacent to footings or walls should be carefully compacted with a light walk-behind roller or vibratory plate compactor to avoid damaging in-place footings or walls.

All foundation excavations should be observed by the Geotechnical Engineer or his representative to explore the extent of any fill, excessively loose, soft, or otherwise undesirable materials. If soft or undesirable materials are encountered in the footing excavations, then such materials should be removed and the subgrade re-established by backfilling. This backfilling may be done with a well-compacted, suitable fill such as clean sand (engineered fill), gravel, or crushed FDOT No. 57 or FDOT No. 67 stone. Sand backfill should be compacted to at least 95 percent of the material’s modified Proctor maximum dry density (ASTM D-1557), as previously described. Gravel/stone should be compacted to a firm/unyielding condition.

Immediately prior to placement of reinforcing steel, it is suggested that the bearing surfaces of all footing and floor slab areas be re-compacted using hand operated mechanical tampers. In this manner, any localized areas that have been loosened by excavation operations should be adequately recompacted.

Provided the recommended subgrade preparation operations presented herein are properly performed, total foundation settlement should be on the order of one inch. Differential settlements should be approximately 50 percent of the total movements. These estimates are based on foundation loads being on the order of magnitude discussed herein. The settlement of shallow foundations supported on sandy soils should occur relatively quickly after initial loading. Thus, the majority of expected settlement should occur during construction as dead loads are imposed.

Lateral loads that are applied to the foundations may be resisted by earth pressure mobilized on the buried vertical faces of the footings and by shearing forces acting along the footing-subgrade interface. Earth pressure resistance may be determined using an equivalent fluid density of 360 pounds per cubic foot for moist soil and 180 pounds per cubic foot for submerged soil below the water table. A friction factor of 0.4 should be used to determine base shearing resistance. The noted values are based on the assumption that the footings are surrounded by compacted sand fill.

PSI Project No. 07571447 Page 8 of 11

To develop passive resistances, the foundations must be able to tolerate some lateral movement. In order to minimize the movement required to develop resistance, the pressure values presented above can be halved. We estimate lateral movements in the range one-quarter to three-eighths of an inch to fully develop the passive resistance. A factor of safety of at least 1.5 is recommended for design.

Floor Slabs

Floor slabs can be safely supported as slab-on-grade systems provided the final subgrade elevation is densified and prepared as recommended herein. We further recommend that the upper one foot of the subgrade soils within the building pad be compacted to at least 95 percent of the maximum dry density of the soil's modified Proctor (ASTM D-1557).

We recommend the floor slab bearing soils be covered by lapped polyethylene sheeting in order to minimize the potential for floor dampness which can affect the performance of floor coverings. This membrane should consist of a minimum six mil thick, single layer of non-corroding, non-deteriorating sheeting material placed to minimize seams and to cover all of the soil below the building floor slabs. Seams should be overlapped a minimum of 12 inches.

For slab design, we recommend a subgrade modulus of 150 pounds per cubic foot (pci) for subgrade prepared as noted herein.

Pavement Support

Provided a minimum separation of 18 inches is maintained between the bottom of the pavement basecourse and the estimated normal seasonal high groundwater table, new pavement base materials can consist of limerock, crushed concrete or soil cement. It should be noted the reflective cracking of the asphalt should be anticipated if soil cement base is used. Based on experience, we recommend the following minimum pavement section for heavy-duty uses, such as in aprons, dumpster pads, and areas to receive heavy truck traffic.

Heavy-Duty (Rigid Pavement)

7.0 inches Portland cement concrete, minimum 28 day compressive strength of 4000 psi.

12.0 inches Well-draining granular subgrade, compacted to 98 percent of the material’s AASHTO T-180 maximum dry density.

PSI Project No. 07571447 Page 9 of 11

As an alternate to the rigid section above, the following heavy-duty asphalt section can be considered for truck driveway areas. However, we recommend the noted rigid section be used for the aprons and dumpster pads.

Heavy-Duty (Asphalt Pavement)

2.5 inches Type S Asphaltic Concrete

10.0 inches Limerock/crushed concrete basecourse (LBR = 100) or soil cement (350 psi design or equivalent)

12.0 inches Stabilized subgrade (LBR=40) if a limerock/crushed concrete base is used or a subgrade compacted to 98 percent of the material’s ASTM D-1557 maximum dry density if soil cement is used as base material.

Pavement joints and reinforcing for concrete pavement should be in accordance with American Concrete Institute (ACI) standards. The recommended pavement sections are based on past experience with similar projects and the encountered subsurface conditions at the site. All pavement materials and construction should meet the more stringent of the Florida Department of Transportation (FDOT) and local city/county requirements. The noted pavement sections should be considered recommended minimums based on anticipated traffic loadings and our past experience.

The project civil engineer should provide the pavement design using actual traffic loads, design criteria provided by the Owner, and the soil and groundwater conditions noted herein.

OTHER CONSIDERATIONS

Site Dewatering

Dewatering will likely be necessary for excavations. If dewatering is necessary, excavations that are only a few feet below the water table can likely be dewatered with a sump pump. Deeper excavations will most likely require well-pointing or sock drains to achieve adequate drawdown.

In either case, the dewatering system should be designed and operated to lower the groundwater table to a depth at least 2 feet below the bottom of surfaces to be compacted in any given area.

The design and discharge of the dewatering system should be in accordance with current regulatory criteria.

Excavations

In Federal Register, Volume 54, No. 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 insure the safety of workmen entering trenches or excavations. It is mandated by this federal regulation that excavations, whether they be utility trenches, general construction excavations or footing excavations, be constructed in accordance with the new OSHA guidelines. It is our 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.

PSI Project No. 07571447 Page 10 of 11

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, 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.

LIMITATIONS

Our professional services have been performed, our findings obtained, and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices.

This company is not responsible for the conclusions, opinions or recommendations made by others based on these data.

The scope of our exploration was intended to evaluate soil conditions within the influence of the proposed building foundations and does not include an evaluation of potential deep soil problems such as sinkholes. The analysis and recommendations submitted in this report are based upon the data obtained from the soil borings performed at the locations indicated. If any subsoil variations become evident during the course of this project, a re-evaluation of the recommendations contained in this report will be necessary after we have had an opportunity to observe the characteristics of the conditions encountered. The applicability of the report should also be reviewed in the event significant changes occur in the design, nature or location of the proposed development.

The scope of our services does not include any environmental assessment or investigation for the presence or absence of hazardous or toxic materials in the soil, groundwater, or surface water within or beyond the site studied. Any statements in this report regarding odors, staining of soils, or other unusual conditions observed are strictly for the information of our client.

PSI Project No. 07571447 Page 11 of 11

CLOSURE

PSI appreciates the opportunity to provide our services to Jacobs on this project. If you have any questions regarding the contents of this report, or if we may be of further service, please contact the undersigned.

Respectfully submitted, PROFESSIONAL SERVICE INDUSTRIES, INC.

Certificate of Authorization No. 3684

Jonathan K. Thrasher, P.E. Robert A. Trompke, P.E.

Project Engineer Principal Consultant/Department Manager Florida License No. 76641 Florida License No. 55456

07571447 (Proposed Fire Crash Rescue Station)

Attachments

Sheet 1 – Boring Location Plan Sheets 2 and 3 – Boring Profiles

APPENDIX

NATIONAL GUARD BUREAU FACILITY

FIRE CRASH / RESCUE STATION

LOCATION PLAN

SCALE: 1"=60'

APPROXIMATE LOCATION OF

STANDARD PENETRATION

APPROXIMATE LOCATION OF

TEST BORING

AUGER BORING

LEGEND

B-4

B-2

B-1

B-3

HA-1

HA-2

HA-3

HA-8

HA-4

HA-9

HA-7

HA-6

HA-5

HA-10

HA-11

SOIL PROFILES

SCALE: 1"=5'

LIGHT GRAY TO DARK BROWN SILTY FINE

SAND, (SM)

ORANGE-BROWN TO GRAY CLAYEY FINE

SAND, (SC))

DARK GRAY CLAYEY SAND, (SC)

UNIFIED SOIL CLASSIFICATION GROUP

SYMBOL

STANDARD PENETRATION RESISTANCE IN

BLOWS PER FOOT USING AN AUTOMATIC

HAMMER

DEPTH TO GROUNDWATER LEVEL IN FEET

WITH DATE OF READING

NATURAL MOISTURE CONTENT IN PERCENT

FINES PASSING #200 SIEVE IN PERCENT

LIQUID LIMIT IN PERCENT

PLASTICITY INDEX

(SP)

N

W

-200

LEGEND

B-1 B-2 B-3 B-4

NATIONAL GUARD BUREAU FACILITY

FIRE CRASH / RESCUE STATION

LL

PI

SOIL PROFILES

SCALE: 1"=5'

HA-1 HA-2 HA-3 HA-4 HA-5

HA-6 HA-7 HA-8 HA-9 HA-10 HA-11

GNE

NATIONAL GUARD BUREAU FACILITY

FIRE CRASH / RESCUE STATION

LIGHT GRAY TO DARK BROWN SILTY FINE

SAND, (SM)

ORANGE-BROWN TO GRAY CLAYEY FINE

SAND, (SC)

DARK GRAY CLAYEY SAND, (SC)

UNIFIED SOIL CLASSIFICATION GROUP

SYMBOL

STANDARD PENETRATION RESISTANCE IN

BLOWS PER FOOT USING AN AUTOMATIC

HAMMER

DEPTH TO GROUNDWATER LEVEL IN FEET

WITH DATE OF READING

FINES PASSING #200 SIEVE IN PERCENT

(SP)

N

-200

LEGEND