B2505ADD2Attachment.pdf

July 17, 2024 BET Project No. G24180

TO: Mr. Johnnie Lohrum Jr JL2 Architecture, LLC 1678 Kingston Road Longwood, Florida 32130

RE: Limited Geotechnical Study Fire Station #83 Addition 1655 East Taylor Road DeLand, Volusia County, Florida

Dear Mr. Lohrum:

As requested, Bechtol Engineering and Testing, Inc. (BET) has completed a limited geotechnical study relative to the construction of a new +/- 800 SF addition to the existing fire station at the above referenced site. The purpose of BET’s limited study was to evaluate physical and strength characteristics of subsurface materials encountered by test borings within the probable construction areas and based on these characteristics, to render opinions as to the overall site subsurface conditions and the materials' potential reaction to proposed construction activities. The following report summarizes BET’s findings and evaluations and provides appropriate earthwork and foundation related recommendations.

1.0 PROPOSED CONSTRUCTION

1.1 Structures

The proposed addition consists of a single-story plumbing, electrical and mechanical building to the northwest of the existing Fire Station, providing an additional ground floor area of approximately 800 square feet (SF). Proposed finish floor elevation (FFE) was not noted, but it anticipated to match the FFE of the existing building. Foundations are anticipated to consist of either conventional strip wall footings and spread column footings with floated slab on grade, or conventional monolithic slab foundation. Design structural loads were not known at the time of this report.

2.0 FIELD STUDY

BET’s field study, completed on June 28th, 2024, consisted of advancing two (2) Standard Penetration Test (SPT) borings (ASTM D-1586) within the proposed building addition area, each to a depth of 20 feet below the existing ground surface. Approximate locations of the test borings are shown on the Boring Location Plan presented on Sheet A1 in Appendix A. Encountered subsurface conditions are presented in the form of soil profiles, also shown on Sheet A1 in Appendix A .

Limited Geotechnical Study - Fire Station #83 Addition - 1655 East Taylor Road, DeLand, Volusia County, Florida

G24180 Limited Geotechnical Study Report.wpd

3.0 ENCOUNTERED SUBSURFACE CONDITIONS

3.1 Soil Conditions

In general, the borings encountered approximately 2 to 3 inches of surficial topsoil/sod deposits comprised of very loose dark brown slightly silty to silty fine sands, with roots (Stratum 1), underlaid by loose to medium dense light gray to gray-brown fine sands (Stratum 2), extending to depths ranging from 2.7 to 5.5 feet below the existing ground surface. Underlying soils consisted of loose to medium dense dark reddish-brown to orangish-brown fine sands, some with cemented sands

(Stratum 3), extending to depths ranging from 6 to 13.5 feet below the existing surface. Underlying soils to the boring termination depths consisted of loose to medium dense light brown to light yellowish-brown fine sands (Stratum 4), and/or loose gray fine sands (Stratum 5). For a more in-depth soil stratification, please refer to the soil profiles presented on Sheet A1 in Appendix A.

3.2 Groundwater Conditions

Groundwater level, as measured at the SPT boring locations, was encountered at depths ranging from 8.5 to 8.8 feet below the ground surface existing at the time of drilling. In reference to approximate ground surface elevations at the boring locations, as interpolated from topographic data shown on the online Florida Geographic Information Office’s LiDAR Mapping, the corresponding groundwater elevations appeared to approximately be on the order of 77' North

American Vertical Datum of 1988 (NAVD).

BET cautions that groundwater levels are subject to variation due to seasonal climate changes and man-induced influences. BET estimates that average seasonal high groundwater levels in the building area are estimated to be approximately 18 to 24 inches above those levels encountered in the field at the time of drilling.

4.0 GEOTECHNICAL EVALUATIONS AND RECOMMENDATIONS

4.1 Suitability of Encountered Soils

As indicated by the soil profiles, up to 3 inches of surficial topsoils/sod containing appreciable quantities of roots and organic matter exist in most areas of the site. Where encountered, surficial topsoils/sod should be removed from structural areas during standard clearing and grubbing operations. Generally, the underlying subgrade soils are granular in nature, and should be suitable as foundation subgrade and as structural fill, pending adequate completion of certain earthwork activities, including clearing and grubbing of vegetation, surface topsoils, removal of debris, and compaction of subgrade and structural fill soils. General Earthwork Recommendations are outlined on the attached Appendix B.

4.2 Foundation Recommendations

The recommended foundation system for the proposed addition to the existing structure is either conventional shallow footings, with floated slab-on-grade, or monolithic slab foundations.

Foundations should be proportioned for maximum soil contact bearing pressure of 2,000 pounds

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Limited Geotechnical Study - Fire Station #83 Addition - 1655 East Taylor Road, DeLand, Volusia County, Florida

G24180 Limited Geotechnical Study Report.wpd per square foot (psf), to include all dead and live loads. Base of strip footings should be a minimum of 24 inches in width. Minimum size of spread column footings should be 24 inches square. Base of conventional footings should be embedded a minimum of 20 inches below lowest adjacent exterior grade. Base of thickened, load bearing monolithic slab sections should be a minimum of 16 inches in width and should be embedded a minimum of 12 inches below lowest adjacent exterior grade. Additionally, footings and walls of additions should be doweled into, or otherwise suitably tied structurally to the foundation and walls of the existing building to minimize potential for differential settlement and separation between the new and existing structures. Actual foundation embedment, dimensions and reinforcing should be determined by a licensed Structural

Engineer based on design structural loads and the above recommended allowable soil bearing pressure. Suitability of the recommended foundation system is dependent on adequate completion of the recommended earthwork activities, as outlined in Appendix B.

4.3 Review of Final Design Criteria

The evaluations and recommendations presented in this report are based partly on assumed design criteria. Final design criteria, including foundation and grading plans and structural loading conditions, should be reviewed by BET in order that they may evaluate the applicability of their recommendations, and provide revised or additional recommendations as may be warranted.

BET appreciates the opportunity to be of service, and trusts this report is complete and sufficient for your needs. However, if you should have any questions or if BET may be of further service, please do not hesitate to call.

Respectfully, Bechtol Engineering and Testing, Inc.

Love B. Patel, P.E.

Senior Geotechnical Engineer Love B. Patel, P.E., State of Florida Professional Engineer, License No. 90753 This item has been digitally signed and sealed by Love B. Patel, P.E. on the date adjacent to the seal. Printed copies of this document are not considered signed and sealed, and the signature must be verified on any electronic copies.

G24180 Limited Geotechnical Study Report.wpd

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APPENDIX A

BORING LOCATION PLAN

SOIL PROFILES

SOIL & SYMBOL LEGEND

TB-1

TB-1

TB-2

A P

P R

O V

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K E

D

F

IE

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1SOIL PROFILES

SOIL & SYMBOL LEGEND

VERTICAL SCALE: 1" = 5'

BORING LOCATION PLAN

SCALE: 1" = 60'

DARK BROWN SLIGHTLY SILTY TO SILTY FINE SAND WITH

ROOTS [TOPSOIL/SOD], (SP-SM)(SM), VERY LOOSE

LIGHT GRAY TO GRAY-BROWN FINE SAND, (SP), LOOSE

TO MEDIUM DENSE

DARK REDDISH-BROWN TO ORANGISH-BROWN FINE

SAND, SOME WITH CEMENTED SANDS, (SP), LOOSE TO

MEDIUM DENSE

LIGHT BROWN TO LIGHT YELLOWISH-BROWN FINE SAND,

(SP), LOOSE TO MEDIUM DENSE

GRAY FINE SAND, (SP), LOOSE

UNIFIED SOIL CLASSIFICATION GROUP SYMBOL AS

DETERMINED BY VISUAL EXAMINATION

GROUNDWATER LEVEL, REFERENCED IN FEET TO

EXISTING GROUND SURFACE, DATE OF READING

STANDARD PENETRATION RESISTANCE IN BLOWS PER

FOOT

APPROXIMATE LOCATION OF STANDARD PENETRATION

TEST BORING

N

(SP)

-8.5

6-28-24

SHOWN ON THE ONLINE FLORIDA GEOGRAPHIC INFORMATION

ELEVATION AT BORING LOCATIONS FROM TOPOGRAPHIC DATA

ELEVATIONS BASED ON INTERPOLATION OF GROUND SURFACE

*NOTE

OFFICES LiDAR MAPPING. ACTUAL ELEVATIONS MAY VARY.

TB-1 TB-2

E L

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N

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F E

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V D

-8.8

6-28-24

-8.5

6-28-24

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IC

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EAST TAYLOR ROAD

100 503020 40 60

SCALE (feet)

APPENDIX B

GENERAL EARTHWORK RECOMMENDATIONS

Limited Geotechnical Study - Fire Station #83 Addition - 1655 East Taylor Road, DeLand, Volusia County, Florida

G24180 Limited Geotechnical Study Report.wpd

APPENDIX B

GENERAL EARTHWORK RECOMMENDATIONS

1.0 CLEARING

1.1 The footprint of the building area, plus suitable margins, should be cleared and stripped of all surface vegetation, organic topsoils/sod, debris, abandoned utilities, and any other deleterious materials which may be encountered.

1.2 Tree removal should include the extraction of stumps and associated root network.

2.0 SUBGRADE SOILS COMPACTION

2.1 Exposed subgrade soils in cleared and stripped building area should be wetted as needed to achieve near-optimum soil moisture conditions, and compacted to the degree and depth recommended below.

2.2 Recommended degree of subgrade soils compaction is 98% of the material’s theoretical maximum dry density, as determined by Modified Proctor Test (ASTM D-1557, AASHTO T-180).

2.3 Recommended depth of subgrade soils compaction is 2 foot below stripped grade or 2 feet below base of foundation elevation, whichever is deeper.

3.0 FILL MATERIAL PLACEMENT AND COMPACTION

3.1 Where applicable, fill soils utilized to raise the building area to desired grade should consist of clean, granular materials with less than 15% passing No. 200 U.S. Standard Sieve.

3.2 Fill soils should be spread in loose lifts not exceeding 16 inches if compacted with heavy compaction equipment, or 8 inches if compacted with light weight hand operated equipment.

3.3 Each successive lift should be wetted as needed to achieve near-optimum soil moisture conditions and compacted by appropriate mechanical means to the degree recommended below.

3.4 Recommended degree of fill soils compaction is 95% of the material’s theoretical maximum dry density, as determined by Modified Proctor Test (ASTM D-1557, AASHTO T-180).

4.0 COMPACTION TESTING

4.1 The recommended depth and degree of compaction for subgrade and fill soils should be verified by in-place density tests conducted in general conformance with appropriate ASTM density testing procedures.

4.2 Density tests should be conducted for each foot of compacted thickness at each test location.

4.3 Recommended minimum frequency of in-place density testing is one (1) location per isolated column footing, one (1) location per 25 lineal feet of strip footing or thickened load bearing monolithic slab section; and every 200 square feet of slab area. Appropriate frequency of testing may vary depending upon construction procedures.

5.0 SPECIAL CONSIDERATIONS

5.1 Foundation and slab areas should be wetted and proof-rolled prior to pouring concrete in order to re-compact surface materials which may have become disturbed by utility installations and other construction activities.

5.2 The earthwork contractor should be aware of nearby structures, and use vibratory compaction equipment with appropriate discretion.

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