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Home My WebLink Aboutsoil test Since 1988 Florida's Leading Engineering Source • Environmental-Geotechnical•Construction Materials Testing•Threshold and Special Inspections•Plan Review d Code Compliance '�TFRN AT10 September 28, 2015 Debra Alexander & Edward Milian 11348 Briarwood Place North Palm Beach, Florida 34995 RE: Soil Exploration - Proposed One-Story Residence 19 Nettles Boulevard (Lot 19 Nettles Island), St. Lucie County, FL GFA Project # 15-2055.00 GFA International performed soil testing with two Standard Penetration Test (SPT) borings at the above referenced project. Concrete was cored through an existing slab to allow access for drilling and to avoid damaging utilities the upper 4 feet were drilled with a hand auger with hand cone penetrometers performed at one foot intervals. Based on the test results, the soil on which the referenced structure is to rest is capable of sustaining a safe bearing capacity of 2,500 psf. The subsurface exploration activities were performed in accordance with Chapter 18 of the Florida Building Code (latest addition) and applicable ASTM standards. For detailed information on subsurface conditions encountered, please refer to the logs attached to this letter. We recommend that the bottom of the footings be founded at a depth of at least 12 inches below finish grade. The depth shall be measured from the lowest adjacent grade. We also recommend a minimum footing width of 18 inches for spread footings and 16 inches for monolithic footings, but not less than 8 inches more than the width of the imposed wall. This report does not state or imply that the foundation soils at the bearing level will remain in the original condition in which they were found during the subsurface exploration activities. Exposure to the environment may weaken the foundation soils at the bearing level if the foundation excavations remain open for a long period of time, or if the foundation soils are exposed to rainfall. Consequently, it is recommended that the excavations for the wall and column footings be performed to final grade and footings constructed as soon as possible to minimize potential damage of the bearing soils. GFA estimates the site is at or near final grade. It is also recommended that the 2 feet below existing grade, the bottom of all new footing excavations and slabs, and all fill material, be compacted to a minimum density of 95% of the Modified Proctor (ASTM D-1557) to a distance of at least 5 feet beyond the building perimeter (if practical), prior to the placement of the concrete for the footings. If compaction cannot be attained due to persistent wetness or the water table near the bottom of the footing excavation, GFA recommends undercutting below bottom of footing and replacement with No. 57 stone for subgrade that cannot be compacted. The rock fill should be compacted and tamped into the excavation and inspected and verified by a representative from GFA, and tested with hand cone penetrometers, probe rods, or density tests. 521 NW Enterprise Drive • Port St. Lucie, Florida 349 6 •c e o da $ 772 924.3575 772 24-3580 fax www.t eamgfa.com , 9 .team fa.com '� OFFICEs THROUGHOUT FLORIDA Proposed One-Story Residence September 28, 2015 19 Nettles Boulevard, St. Lucie County, FL GFA Project# 15-2055.00 Foundations and any below grade remains of any structures that are within the footprint of the new construction should be removed so as to not affect structures. Analysis of the foundation performance under hurricane conditions or other storm events, including the effects of loss of soil support due to scour or other forces, is not within the scope of this report, and the recommendations are valid only for normal conditions. If there is a nearby seawall or retaining wall, it must have the structural integrity to withstand the loadings imposed by the new structure. Evaluation and design of the nearby seawalls and retaining walls are the responsibility of the structural engineer, specialty engineer, contractor, or others. Evaluation of the seawall is not within our scope of work. Sincerely, GFA International, Inc. FBPE CA#� 0 1 Id M, an Collie, E.I. Senior Geoteihnical Engineer r j t Manager I�o�rida Fi istration NJ. 6 75 , R t t� �.a�..�: Atta . ap ��•�##of 10d+tocation Plan Standard Penetration Test (SPT) Borings (2) Notes Related to Test Borings Copies: Client (2) Vicinity . • Proposed • Residence• Nettles Blvd (Lot 19 Nettles Island) St. Lucie County, FL GFA Project No. 15-2055.00 •cation Note:Aerial Photograph from GoogleEarth Website ' ar ti'. 19y514 lotl?'.!3G`[4i,� to+`SiJ.?77951= Fle=. -i tt e•:e �.itvi:� Yt;�, GNAIkC" Test Location Plan Proposed One-Story Residence 19 Nettles Blvd (Lot 19 Nettles Island) St. Lucie County, FL GFA Project No. 15-2055.00 N_ ee 4% t � Q ♦ 1 Af <SPT-1 SPT-2 Le en Approximate Standard Penetration Test(SPT)Boring Locations • GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE,PORT ST. Lccir,FLORIDA 34986 PHONE: (772)924-3575 - FAX:(772)924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: Debra Alexander& Edward Millan Project No.:15-2055.00 Lab No.: Project: Proposed One-Story Residence Page: I of 1 19 Nettles Blvd(Lot 19 Nettles Island),St. Lucie County,FL Date: 9/24/2015 Elevation: Existing Grade Drill Rig: Simco-24 Water Level:5 feet after 0 hours Drilling Fluid commenced at depth of 10 feet Field Party:WN/KT Hand Auger with Hand Cone Pentrometer Test(HCP in ksf)performed in top 4 feet TEST LOCATION: SPT- 1 N27.28704° W80.22637° Laboratory Tests Depth Blows/ N Sample Laver: Passing Moisture Organic (feet) 6 in. Value No. From/to USCS Description No.200 Content Content 0 _ 0-%z Concrete(4 inches) 1 HCP= 80+ %2 - 5 SP Brown fine sand,trace shell -- 2 HCP= 80+ 3 HCP= 80+ 2 -- 4 HCP= 80+ 12 5 ...g... ...... 7 15 3 5 - 10 SP Gray fine sand,trace shell 5 --• 7 6 ... ... ...... 6 12 4 8 7 .-- 9 ..1U.. ...... 13 23 5 ...same, little shell to -.15.. ...... g Borin Terminated at 10 feet 11 .... .... 12 .... .... 13 .... .... 14 .... .... 15 ....... ...... 16 .... .... 17 .... .... 18 .... .... 19 ....... ...... • GFA INTERNATIONAL 521 N.W. ENTERPRISE DRIVE. PORT Sr. LuCll;FLORIDA 34986 PHONE: (772)924-3575 - FAx: (772)924-3580 STANDARD PENETRATION TEST BORING (ASTM D-1586) Client: Debra Alexander& Edward Millan Project No.:15-2055.00 Lab No.: Project: Proposed One-Story Residence Page: I of 1 19 Nettles Blvd(Lot 19 Nettles Island),St. Lucie County,FL Date: 9/24/2015 Elevation: Existing Grade Drill Rig: Simco-24 Water Level:4%feet after 0 hours Drilling Fluid commenced at depth of 10 feet Field Party: WN/KT Hand Auger with Hand Cone Pentrometer Test(HCP in ksf)performed in top 4 feet TEST LOCATION: SPT- 2 N27.287010 W80.226390 Laboratory Tests Depth Blows/ N Sample Layer: Passing Moisture Organic (feet) 6 in. lValuel No. From/to USCS Description No.200 Content Content 0 0- % Concrete(4 1/2 inches) 1 HCP= 80+ %z - 5 SP Brown fine sand,little shell -- 2 HCP= 80+ - 3 HCP= 80+ _ 2 HCP= 80+ 10 11 _ 5 13 23 3 5- 8 SP Gray fine sand,some shell 6 14. .... 11 -- 7 13 .. ... ...... _-_ 15 28 4 8 16 ...... 10 8 - 10 SP Gray fine sand, little shell 9 -. 7 16 5 to ...7... .... II .... .... 12 .•• .... 13 ..... .... 14 3 131/- 15 SP Gray fine sand,trace silt 3 15 ..-5... ...... 16 .... .... 17 .... .... 18 .... .... 19 7 18'/- 20 SP Gray fine sand and shell 13 -- 10 23 Boring Terminated at 20 feet NOTES RELATED TO RECORDS OF TEST BORING AND GENERALIZED SUBSURFACE PROFILE 1. Groundwater level was encountered and recorded(if shown) following the completion of the soil test boring on the date indicated.Fluctuations in groundwater levels are common;consult report text for a discussion. 2. The boring location was identified in the field by offsetting from existing reference marks and using a cloth tape and survey wheel. 3. The borehole was backfilled to site grade following boring completion,and patched with asphalt cold patch mix when pavement was encountered. 4. The Record of Test Boring represents our interpretation of field conditions based on engineering examination of the soil samples. 5. The Record of Test Boring is subject to the limitations,conclusions and recommendations presented in the Report text. ' 6. "Field Test Data"shown on the Record of Test Boring indicated as 11/6 refers to the Standard Penetration Test (SPT)and means 11 hammer blows drove the sampler 6 inches.SPT uses a 140-pound hammer falling 30 inches. 7. The N-value from the SPT is the sum of the hammer blows required to drive the sampler the second and third 6- inch increments. 8. The soil/rock strata interfaces shown on the Records of Test Boring are approximate and may vary from those shown.The soil/rock conditions shown on the Records of Test Boring refer to conditions at the specific location tested;soil/rock conditions may vary between test locations. 9. Relative density for sands/gravels and consistency for silts/clays are described as follows: SPT CPT SANDS/GRAVELS SPT CPT SILTS/CLAYS BLOWS/F T KG/CM-' RELATIVE DENSITY BLOWS/FOOT KGiCM- CONSISTENCY 0-4 0-16 Very loose 0-1 0-3 Very soft 5-10 17-40 Loose 2-4 4-6 Soft 11-30 41-120 Medium Dense 5-8 7-12 Firm 31-50 121-200 Dense 9-15 13-25 Stiff 50+ over 200 1 Very Dense 16-30 25-50 Very stiff >30 >50 Hard 10. Grain size descriptions are as follows: N M SIZE LIMITS Boulder 12 Inches or more Cobbles 3 to 12 Inches Coarse Gravel %to 3 Inches Fine Gravel No.4 sieve to%inch Coarse Sand No. 10 to No.4 sieve Medium Sand No.40 to No. 10 sieve Fine Sand No.200 to No.40 sieve Fines Smaller than No.200 sieve 11. Definitions related to adjectives used in soil/rock descriptions: PROPORTION ADJECTIVE APPROXIMATE ROOT DIAMETER ADJECTIVE <5% Trace Less than 1/32" Fine roots 5%to 12% Little 1/32"to'/:' Small roots 12%to 300/6 Some ''/:'to I" Medium roots 30%to 50% And Greater than 1" Large roots Organic Soils:Soils containing vegetable tissue in various stages of decomposition that has a fibrous to amorphous texture, usually a dark brown to black color,and an organic odor. Organic Content<25%:Slightly to Highly Organic;25%to 75%:Muck;>75%:Peat