HomeMy WebLinkAboutEngineering & TestingDocuSign Envelope ID: 08616A47-913D-43B4-AF9C-A4DC1 D267DD5
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3866 PROSPECT AVENUE ® SUITE 9 ® WEST PALM BEACH, FLORIDA 33404 ® (561) 881-1939
30 March 2022
Phoenix Custom Homes
1760 Jog Road, Suite 120
West Palm Beach, FL 33411
Subject: Addendum to Report of Geotechnical Services - 3-Level Custom Home
8228 South Ocean Drive, Diamond Sands Lot 36 Jensen Beach, Florida
Allterra Engineering & Testing respectfully submits this addendum to its report of
geotechnical services for the subject project dated 8 March 2021. This addendum
revises conclusions and recommendations about auger -cast pile capacity, load
deflection, and design. This addendum is Allterra's instrument -of -service provided for
sole reliance and use by Phoenix Custom Homes. Third parties may read this report for
information purposes.
A digital copy of a memorandum dated March 14, 2022, and entitled Design Wave
Condition, 8228 S. Ocean Drive, Jensen Beach, St. Lucie County, Florida by Isiminger &
Stubbs Engineering was provided for Allterra's refence in performing its services. The
memorandum presented information on design eroded -grade elevation, breaking wave
crest elevation, still water elevation, wave and debris impact forces on square and round
piles, and hydrodynamic wave forces
Allterra applied the memorandum's information and conceptual subsurface profile from
the 8-March 2021 geotechnical services report to its design model. Allterra estimated the
following capacities for 14-inch and 16-inch auger -cast piles installed to approximately
27 feet below surface grade (approximately 19 feet below scour grade).
Pile Diameter CULTIMATE CALLOWABLE CULT / CALLOW Uplift Resistance
Notes: CULTIMATE = ultimate compressive load capacity.
CALLOWABLE = allowable compressive load capacity.
CULT/CALLOW = CULTIMATE / CALLOWABLE
Uplift Resistance = (weight of pile + skin friction)/1.5.
Kips = 1000 pounds.
Considering the breaking wave crest elevation of +15.5 feet NAVD and FF elevation
from site plans, Allterra assumed a low structural floor beam at +17 feet NAVD
(approximately 18 feet above eroded grade). Model lateral displacements for fixed -toe
fixed -head piles installed to approximately 29 feet below surface grade (approximately
18 feet below scour grade) are summarized in following table:
Pile Diameter • - • • • Displacement
14 inches 2.0 inches 0.5 inch
16 inches 1.1 inches 0.4 inch
Addendum to Geotechnical Services 1 8228 South Ocean Drive, Jensen Beach, FL
30 March 2022 21 - 179
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DocuSign Envelope ID: 08616A47-913D-43134-AF9C-A4DC1D267DD5
For auger -cast piles, Allterra recommends:
Pile Materials. Piles shall be formed with minimum 4000 PSI grout placed under
pressure. as the auger is progressively withdrawn from the borehole. Piles (14-inch
diameter) shall be reinforced with five full -depth number-5 steel bars and number-3 ties
spaced not more than 16 inches on -center. Piles (16-inch diameter) shall be reinforced
with seven full -depth number-5 steel bars and number-3 ties spaced not more than 16
inches on -center. The structural engineer shall determine the number and distribution of
piles, considering structural loads and geometry.
Pile Layout. The number and distribution of piles shall be determined by the structural
engineer considering project loads and geometry. Piles shall be spaced at -least 3
diameters center -to -center to avoid group effect on stress distribution in the bearing
stratum.
Pile -Installation Monitoring. Engage Allterra to monitor installation of piles. For
auger -cast piles, monitoring shall include:
1. Check pile layout for conformance to design foundation plan.
2. Observe field trial and calculate gout -pump factor.
3. Observe drilling of pile to verify target depths are achieved.
4. Observe grouting of pile bore to verify acceptable grout return.
5. Sample grout for compressive -strength testing.
6. Observe installation of reinforcing steel to verify full -depth penetration.
7. Test grout specimens to verify design compressive strength is achieved.
8. Calculate grout factors and summarize installation data for each pile.
9. Prepare report of work acceptance signed and sealed by Professional Engineer.
Please call the undersigned if one has questions about this report or needs other
services. \\� 11IIIIIII it/
Yours truly, ��` ��NEW ►Nq ��,�
Allterra Engineeriiig.&PTesi�fg
FBPE Registry No. @39
oocusigned by: No. 81271
EEF7B2552F31748A...
Matthew Watts P�?0 • STATE OF ���
Senior. Engineer ss•"tORIDP. G\��
FL Lic. No. 81271 ' �, 'ONAI-
1111111110
C: Rob Agsten, PE
This'item has been digitally signed and sealed by
Matthew Watts, PE 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 electronic copies.
Addendum to Geotechnicai Services 2 8228 South Ocean Drive, Jensen Beach, FL
30 March 2022 29 -179